滑块导航点未突出显示

Question

我的滑块部分由点组成，表示哪个幻灯片处于活动状态。因此，当幻灯片被激活时，其关联的点应该变为蓝色。

但是当我的幻灯片出现时，我无法突出显示最后一个（第三个）点。

有人可以帮我解决问题吗？ 谢谢。

到目前为止我的代码：

＆＃13;

＆＃13;

var prevDot = 0;

function init() {

    var elem = document.getElementById('mySwipe');
    window.mySwipe = Swipe(elem, {
        // startSlide: 4,
        // auto: 3000,
        // continuous: true,
        // disableScroll: true,
        // stopPropagation: true,
        // callback: function(index, element) {},
        transitionEnd: function(index, element) {
            $(".swipeDot").find("li").eq(prevDot).removeClass("dot_select");
            prevDot = (index == 0 || index == 2) ? 0 : 1;
            $(".swipeDot").find("li").eq(prevDot).addClass("dot_select");

            console.log(index);
        }
    });

    //$(".swipe-wrap").find("div").eq(2).find("span").css({backgroundImage:"url('../images/p006_img_2.png')"})
    $("#prevBtn").click(function() {
        window.mySwipe.prev();
    });

    $("#nextBtn").click(function() {
        window.mySwipe.next();
    });

    $(".swipeDot li").each(function(index) {
        $(this).attr("slideIndex", index);
    });

    $(".swipeDot li").click(function() {
        var slideIndex = $(this).attr("slideIndex");
        window.mySwipe.slide(slideIndex);
    });

}



$(document).ready(init);




function Swipe(container, options) {
    console.log(container);
    "use strict";

    // utilities
    var noop = function() {}; // simple no operation function
    var offloadFn = function(fn) {
        setTimeout(fn || noop, 0)
    }; // offload a functions execution

    // check browser capabilities
    var browser = {
        addEventListener: !!window.addEventListener,
        touch: ('ontouchstart' in window) || window.DocumentTouch && document instanceof DocumentTouch,
        transitions: (function(temp) {
            var props = ['transitionProperty', 'WebkitTransition', 'MozTransition', 'OTransition', 'msTransition'];
            for (var i in props)
                if (temp.style[props[i]] !== undefined) return true;
            return false;
        })(document.createElement('swipe'))
    };

    // quit if no root element
    if (!container) return;
    var element = container.children[0];
    var slides, slidePos, width, length;
    options = options || {};
    var index = parseInt(options.startSlide, 10) || 0;
    var speed = options.speed || 300;
    options.continuous = options.continuous !== undefined ? options.continuous : true;

    function setup() {

        // cache slides
        slides = element.children;
        length = slides.length;

        // set continuous to false if only one slide
        if (slides.length < 2) options.continuous = false;



        //special case if two slides
        if (browser.transitions && options.continuous && slides.length < 3) {
            element.appendChild(slides[0].cloneNode(true));
            element.appendChild(element.children[1].cloneNode(true));

            slides = element.children;
        }

        // create an array to store current positions of each slide
        slidePos = new Array(slides.length);

        // determine width of each slide
        width = container.offsetWidth;

        element.style.width = (slides.length * width) + 'px';

        // stack elements
        var pos = slides.length;

        while (pos--) {

            var slide = slides[pos];

            slide.style.width = width + 'px';

            slide.setAttribute('data-index', pos);

            if (browser.transitions) {
                slide.style.left = (pos * -width) + 'px';
                move(pos, index > pos ? -width : (index < pos ? width : 0), 0);
            }

        }

        // reposition elements before and after index
        if (options.continuous && browser.transitions) {
            move(circle(index - 1), -width, 0);
            move(circle(index + 1), width, 0);
        }

        if (!browser.transitions) element.style.left = (index * -width) + 'px';

        container.style.visibility = 'visible';

    }

    function prev() {

        if (options.continuous) slide(index - 1);
        else if (index) slide(index - 1);

    }

    function next() {

        if (options.continuous) slide(index + 1);
        else if (index < slides.length - 1) slide(index + 1);

    }

    function circle(index) {

        // a simple positive modulo using slides.length
        return (slides.length + (index % slides.length)) % slides.length;

    }

    function slide(to, slideSpeed) {

        // do nothing if already on requested slide
        if (index == to) return;

        if (browser.transitions) {

            var direction = Math.abs(index - to) / (index - to); // 1: backward, -1: forward

            // get the actual position of the slide
            if (options.continuous) {
                var natural_direction = direction;
                direction = -slidePos[circle(to)] / width;

                // if going forward but to < index, use to = slides.length + to
                // if going backward but to > index, use to = -slides.length + to
                if (direction !== natural_direction) to = -direction * slides.length + to;

            }

            var diff = Math.abs(index - to) - 1;

            // move all the slides between index and to in the right direction
            while (diff--) move(circle((to > index ? to : index) - diff - 1), width * direction, 0);

            to = circle(to);

            move(index, width * direction, slideSpeed || speed);
            move(to, 0, slideSpeed || speed);

            if (options.continuous) move(circle(to - direction), -(width * direction), 0); // we need to get the next in place

        } else {

            to = circle(to);
            animate(index * -width, to * -width, slideSpeed || speed);
            //no fallback for a circular continuous if the browser does not accept transitions
        }

        index = to;
        offloadFn(options.callback && options.callback(index, slides[index]));
    }

    function move(index, dist, speed) {

        translate(index, dist, speed);
        slidePos[index] = dist;

    }

    function translate(index, dist, speed) {

        var slide = slides[index];
        var style = slide && slide.style;

        if (!style) return;

        style.webkitTransitionDuration =
            style.MozTransitionDuration =
            style.msTransitionDuration =
            style.OTransitionDuration =
            style.transitionDuration = speed + 'ms';

        style.webkitTransform = 'translate(' + dist + 'px,0)' + 'translateZ(0)';
        style.msTransform =
            style.MozTransform =
            style.OTransform = 'translateX(' + dist + 'px)';

    }

    function animate(from, to, speed) {

        // if not an animation, just reposition
        if (!speed) {

            element.style.left = to + 'px';
            return;

        }

        var start = +new Date;

        var timer = setInterval(function() {

            var timeElap = +new Date - start;

            if (timeElap > speed) {

                element.style.left = to + 'px';

                if (delay) begin();

                options.transitionEnd && options.transitionEnd.call(event, index, slides[index]);

                clearInterval(timer);
                return;

            }

            element.style.left = (((to - from) * (Math.floor((timeElap / speed) * 100) / 100)) + from) + 'px';

        }, 4);

    }

    // setup auto slideshow
    var delay = options.auto || 0;
    var interval;

    function begin() {

        interval = setTimeout(next, delay);

    }

    function stop() {

        delay = 0;
        clearTimeout(interval);

    }


    // setup initial vars
    var start = {};
    var delta = {};
    var isScrolling;

    // setup event capturing
    var events = {

        handleEvent: function(event) {

            switch (event.type) {
                case 'touchstart':
                    this.start(event);
                    break;
                case 'touchmove':
                    this.move(event);
                    break;
                case 'touchend':
                    offloadFn(this.end(event));
                    break;
                case 'webkitTransitionEnd':
                case 'msTransitionEnd':
                case 'oTransitionEnd':
                case 'otransitionend':
                case 'transitionend':
                    offloadFn(this.transitionEnd(event));
                    break;
                case 'resize':
                    offloadFn(setup);
                    break;
            }

            if (options.stopPropagation) event.stopPropagation();

        },
        start: function(event) {

            var touches = event.touches[0];

            // measure start values
            start = {

                // get initial touch coords
                x: touches.pageX,
                y: touches.pageY,

                // store time to determine touch duration
                time: +new Date

            };

            // used for testing first move event
            isScrolling = undefined;

            // reset delta and end measurements
            delta = {};

            // attach touchmove and touchend listeners
            element.addEventListener('touchmove', this, false);
            element.addEventListener('touchend', this, false);

        },
        move: function(event) {

            // ensure swiping with one touch and not pinching
            if (event.touches.length > 1 || event.scale && event.scale !== 1) return

            if (options.disableScroll) event.preventDefault();

            var touches = event.touches[0];

            // measure change in x and y
            delta = {
                x: touches.pageX - start.x,
                y: touches.pageY - start.y
            }

            // determine if scrolling test has run - one time test
            if (typeof isScrolling == 'undefined') {
                isScrolling = !!(isScrolling || Math.abs(delta.x) < Math.abs(delta.y));
            }

            // if user is not trying to scroll vertically
            if (!isScrolling) {

                // prevent native scrolling
                event.preventDefault();

                // stop slideshow
                stop();

                // increase resistance if first or last slide
                if (options.continuous) { // we don't add resistance at the end

                    translate(circle(index - 1), delta.x + slidePos[circle(index - 1)], 0);
                    translate(index, delta.x + slidePos[index], 0);
                    translate(circle(index + 1), delta.x + slidePos[circle(index + 1)], 0);

                } else {

                    delta.x =
                        delta.x /
                        ((!index && delta.x > 0 // if first slide and sliding left
                                ||
                                index == slides.length - 1 // or if last slide and sliding right
                                &&
                                delta.x < 0 // and if sliding at all
                            ) ?
                            (Math.abs(delta.x) / width + 1) // determine resistance level
                            :
                            1); // no resistance if false

                    // translate 1:1
                    translate(index - 1, delta.x + slidePos[index - 1], 0);
                    translate(index, delta.x + slidePos[index], 0);
                    translate(index + 1, delta.x + slidePos[index + 1], 0);
                }

            }

        },
        end: function(event) {

            // measure duration
            var duration = +new Date - start.time;

            // determine if slide attempt triggers next/prev slide
            var isValidSlide =
                Number(duration) < 250 // if slide duration is less than 250ms
                &&
                Math.abs(delta.x) > 20 // and if slide amt is greater than 20px
                ||
                Math.abs(delta.x) > width / 2; // or if slide amt is greater than half the width

            // determine if slide attempt is past start and end
            var isPastBounds = !index && delta.x > 0 // if first slide and slide amt is greater than 0
                ||
                index == slides.length - 1 && delta.x < 0; // or if last slide and slide amt is less than 0

            if (options.continuous) isPastBounds = false;

            // determine direction of swipe (true:right, false:left)
            var direction = delta.x < 0;

            // if not scrolling vertically
            if (!isScrolling) {

                if (isValidSlide && !isPastBounds) {

                    if (direction) {

                        if (options.continuous) { // we need to get the next in this direction in place

                            move(circle(index - 1), -width, 0);
                            move(circle(index + 2), width, 0);

                        } else {
                            move(index - 1, -width, 0);
                        }

                        move(index, slidePos[index] - width, speed);
                        move(circle(index + 1), slidePos[circle(index + 1)] - width, speed);
                        index = circle(index + 1);

                    } else {
                        if (options.continuous) { // we need to get the next in this direction in place

                            move(circle(index + 1), width, 0);
                            move(circle(index - 2), -width, 0);

                        } else {
                            move(index + 1, width, 0);
                        }

                        move(index, slidePos[index] + width, speed);
                        move(circle(index - 1), slidePos[circle(index - 1)] + width, speed);
                        index = circle(index - 1);

                    }

                    options.callback && options.callback(index, slides[index]);

                } else {

                    if (options.continuous) {

                        move(circle(index - 1), -width, speed);
                        move(index, 0, speed);
                        move(circle(index + 1), width, speed);

                    } else {

                        move(index - 1, -width, speed);
                        move(index, 0, speed);
                        move(index + 1, width, speed);
                    }

                }

            }

            // kill touchmove and touchend event listeners until touchstart called again
            element.removeEventListener('touchmove', events, false)
            element.removeEventListener('touchend', events, false)

        },
        transitionEnd: function(event) {

            if (parseInt(event.target.getAttribute('data-index'), 10) == index) {

                if (delay) begin();

                options.transitionEnd && options.transitionEnd.call(event, index, slides[index]);

            }

        }

    }

    // trigger setup
    setup();

    // start auto slideshow if applicable
    if (delay) begin();


    // add event listeners
    if (browser.addEventListener) {

        // set touchstart event on element
        if (browser.touch) element.addEventListener('touchstart', events, false);

        if (browser.transitions) {
            element.addEventListener('webkitTransitionEnd', events, false);
            element.addEventListener('msTransitionEnd', events, false);
            element.addEventListener('oTransitionEnd', events, false);
            element.addEventListener('otransitionend', events, false);
            element.addEventListener('transitionend', events, false);
        }

        // set resize event on window
        window.addEventListener('resize', events, false);

    } else {

        window.onresize = function() {
            setup()
        }; // to play nice with old IE

    }

    // expose the Swipe API
    return {
        setup: function() {

            setup();

        },
        slide: function(to, speed) {

            // cancel slideshow
            stop();

            slide(to, speed);

        },
        prev: function() {

            // cancel slideshow
            stop();

            prev();

        },
        next: function() {

            // cancel slideshow
            stop();

            next();

        },
        stop: function() {

            // cancel slideshow
            stop();

        },
        getPos: function() {

            // return current index position
            return index;

        },
        getNumSlides: function() {

            // return total number of slides
            return length;
        },
        kill: function() {

            // cancel slideshow
            stop();

            // reset element
            element.style.width = '';
            element.style.left = '';

            // reset slides
            var pos = slides.length;
            while (pos--) {

                var slide = slides[pos];
                slide.style.width = '';
                slide.style.left = '';

                if (browser.transitions) translate(pos, 0, 0);

            }

            // removed event listeners
            if (browser.addEventListener) {

                // remove current event listeners
                element.removeEventListener('touchstart', events, false);
                element.removeEventListener('webkitTransitionEnd', events, false);
                element.removeEventListener('msTransitionEnd', events, false);
                element.removeEventListener('oTransitionEnd', events, false);
                element.removeEventListener('otransitionend', events, false);
                element.removeEventListener('transitionend', events, false);
                window.removeEventListener('resize', events, false);

            } else {

                window.onresize = null;

            }

        }
    }

}


if (window.jQuery || window.Zepto) {
    (function($) {
        $.fn.Swipe = function(params) {
            return this.each(function() {
                $(this).data('Swipe', new Swipe($(this)[0], params));
            });
        }
    })(window.jQuery || window.Zepto)
}

＆＃13;

ul, li{display: inline-block; list-style:none}
li, .swipeBtn{cursor: pointer}
li+li{margin-left:10px}
li::before {content:'●'; color:grey}
.dot_select::before{color: blue}
#mySwipe{overflow: hidden}

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="swipeBtn hotspot hspot cElement" id="prevBtn">&#x2770;</div>
<div id='mySwipe' style='width:600px;margin:0 auto' class='swipe hotspot hspot cElement'>
  <div class='swipe-wrap'>
    <div><span id="slide1">---- SLIDE1 ----</span></div>
    <div><span id="slide2">---- SLIDE2 ----</span></div>
	 <div><span id="slide3">---- SLIDE3 ----</span></div>
  </div>
</div>
<div class="swipeBtn hotspot hspot cElement" id="nextBtn">&#x2771;</div>
<ul class="swipeDot">
	<li class="dot_select"></li>
	<li ></li>
	<li></li>
</ul>

＆＃13;

＆＃13;

＆＃13;

Answer 1

添加了下一行

prevDot=index;  
$(".swipeDot").find("li").eq(index).addClass("dot_select");

这将保存活动点的值。第二行是你的，但我只是将eq(prevdot)更改为eq(index)

Fior在评论中说明了问题。我重新编写了代码并在js的第174行找到了错误。

你有  if（direction！== natural_direction）to = -direction * slides.length + to;

此行在结束操作之前更改了to的值并返回了垃圾。所以我刚刚更改了to的{​​{1}} var并且运行正常。这是一个长脚本的debbuge。可能有一个更好的解决方案，但这是我得到的。

希望这就是你要找的东西。如果需要，很乐意解释或帮助提供更好的解决方案。

＆＃13;

＆＃13;

newTo

＆＃13;

var prevDot = 0;

function init() {

  var elem = document.getElementById('mySwipe');
  window.mySwipe = Swipe(elem, {
    // startSlide: 4,
    // auto: 3000,
    // continuous: true,
    // disableScroll: true,
    // stopPropagation: true,
    // callback: function(index, element) {},
    transitionEnd: function(index, element) {
      $(".swipeDot").find("li").eq(prevDot).removeClass("dot_select");
      prevDot = (index == 0 || index == 2) ? 0 : 1;
    prevDot=index;  $(".swipeDot").find("li").eq(index).addClass("dot_select");

      console.log(index);
    }
  });

  //$(".swipe-wrap").find("div").eq(2).find("span").css({backgroundImage:"url('../images/p006_img_2.png')"})
  $("#prevBtn").click(function() {
    window.mySwipe.prev();
  });

  $("#nextBtn").click(function() {
    window.mySwipe.next();
  });

  $(".swipeDot li").each(function(index) {
    $(this).attr("slideIndex", index);
  });

  $(".swipeDot li").click(function() {
    var slideIndex = $(this).attr("slideIndex");
    window.mySwipe.slide(slideIndex);
  });

}



$(document).ready(init);




function Swipe(container, options) {
  console.log(container);
  "use strict";

  // utilities
  var noop = function() {}; // simple no operation function
  var offloadFn = function(fn) {
    setTimeout(fn || noop, 0)
  }; // offload a functions execution

  // check browser capabilities
  var browser = {
    addEventListener: !!window.addEventListener,
    touch: ('ontouchstart' in window) || window.DocumentTouch && document instanceof DocumentTouch,
    transitions: (function(temp) {
      var props = ['transitionProperty', 'WebkitTransition', 'MozTransition', 'OTransition', 'msTransition'];
      for (var i in props)
        if (temp.style[props[i]] !== undefined) return true;
      return false;
    })(document.createElement('swipe'))
  };

  // quit if no root element
  if (!container) return;
  var element = container.children[0];
  var slides, slidePos, width, length;
  options = options || {};
  var index = parseInt(options.startSlide, 10) || 0;
  var speed = options.speed || 300;
  options.continuous = options.continuous !== undefined ? options.continuous : true;

  function setup() {

    // cache slides
    slides = element.children;
    length = slides.length;

    // set continuous to false if only one slide
    if (slides.length < 2) options.continuous = false;



    //special case if two slides
    if (browser.transitions && options.continuous && slides.length < 3) {
      element.appendChild(slides[0].cloneNode(true));
      element.appendChild(element.children[1].cloneNode(true));

      slides = element.children;
    }

    // create an array to store current positions of each slide
    slidePos = new Array(slides.length);

    // determine width of each slide
    width = container.offsetWidth;

    element.style.width = (slides.length * width) + 'px';

    // stack elements
    var pos = slides.length;

    while (pos--) {

      var slide = slides[pos];

      slide.style.width = width + 'px';

      slide.setAttribute('data-index', pos);

      if (browser.transitions) {
        slide.style.left = (pos * -width) + 'px';
        move(pos, index > pos ? -width : (index < pos ? width : 0), 0);
      }

    }

    // reposition elements before and after index
    if (options.continuous && browser.transitions) {
      move(circle(index - 1), -width, 0);
      move(circle(index + 1), width, 0);
    }

    if (!browser.transitions) element.style.left = (index * -width) + 'px';

    container.style.visibility = 'visible';

  }

  function prev() {

    if (options.continuous) slide(index - 1);
    else if (index) slide(index - 1);

  }

  function next() {

    if (options.continuous) slide(index + 1);
    else if (index < slides.length - 1) slide(index + 1);

  }

  function circle(index) {

    // a simple positive modulo using slides.length
    return (slides.length + (index % slides.length)) % slides.length;

  }

  function slide(to, slideSpeed) {

    // do nothing if already on requested slide
    if (index == to) return;
    
    if (browser.transitions) {

      var direction = Math.abs(index - to) / (index - to); // 1: backward, -1: forward

      // get the actual position of the slide
      if (options.continuous) {
        var natural_direction = direction;
        direction = -slidePos[circle(to)] / width;

        // if going forward but to < index, use to = slides.length + to
        // if going backward but to > index, use to = -slides.length + to
        if (direction !== natural_direction) newTo = -direction * slides.length + to;
      }

      var diff = Math.abs(index - to) - 1;

      // move all the slides between index and to in the right direction
      while (diff--) move(circle((to > index ? to : index) - diff - 1), width * direction, 0);

      to = circle(to);

      move(index, width * direction, slideSpeed || speed);
      move(to, 0, slideSpeed || speed);

      if (options.continuous) move(circle(to - direction), -(width * direction), 0); // we need to get the next in place

    } else {

      to = circle(to);
      animate(index * -width, to * -width, slideSpeed || speed);
      //no fallback for a circular continuous if the browser does not accept transitions
    }

    index = to;
    offloadFn(options.callback && options.callback(index, slides[index]));
  }

  function move(index, dist, speed) {

    translate(index, dist, speed);
    slidePos[index] = dist;

  }

  function translate(index, dist, speed) {

    var slide = slides[index];
    var style = slide && slide.style;

    if (!style) return;

    style.webkitTransitionDuration =
      style.MozTransitionDuration =
      style.msTransitionDuration =
      style.OTransitionDuration =
      style.transitionDuration = speed + 'ms';

    style.webkitTransform = 'translate(' + dist + 'px,0)' + 'translateZ(0)';
    style.msTransform =
      style.MozTransform =
      style.OTransform = 'translateX(' + dist + 'px)';

  }

  function animate(from, to, speed) {

    // if not an animation, just reposition
    if (!speed) {

      element.style.left = to + 'px';
      return;

    }

    var start = +new Date;

    var timer = setInterval(function() {

      var timeElap = +new Date - start;

      if (timeElap > speed) {

        element.style.left = to + 'px';

        if (delay) begin();

        options.transitionEnd && options.transitionEnd.call(event, index, slides[index]);

        clearInterval(timer);
        return;

      }

      element.style.left = (((to - from) * (Math.floor((timeElap / speed) * 100) / 100)) + from) + 'px';

    }, 4);

  }

  // setup auto slideshow
  var delay = options.auto || 0;
  var interval;

  function begin() {

    interval = setTimeout(next, delay);

  }

  function stop() {

    delay = 0;
    clearTimeout(interval);

  }


  // setup initial vars
  var start = {};
  var delta = {};
  var isScrolling;

  // setup event capturing
  var events = {

    handleEvent: function(event) {

      switch (event.type) {
        case 'touchstart':
          this.start(event);
          break;
        case 'touchmove':
          this.move(event);
          break;
        case 'touchend':
          offloadFn(this.end(event));
          break;
        case 'webkitTransitionEnd':
        case 'msTransitionEnd':
        case 'oTransitionEnd':
        case 'otransitionend':
        case 'transitionend':
          offloadFn(this.transitionEnd(event));
          break;
        case 'resize':
          offloadFn(setup);
          break;
      }

      if (options.stopPropagation) event.stopPropagation();

    },
    start: function(event) {

      var touches = event.touches[0];

      // measure start values
      start = {

        // get initial touch coords
        x: touches.pageX,
        y: touches.pageY,

        // store time to determine touch duration
        time: +new Date

      };

      // used for testing first move event
      isScrolling = undefined;

      // reset delta and end measurements
      delta = {};

      // attach touchmove and touchend listeners
      element.addEventListener('touchmove', this, false);
      element.addEventListener('touchend', this, false);

    },
    move: function(event) {

      // ensure swiping with one touch and not pinching
      if (event.touches.length > 1 || event.scale && event.scale !== 1) return

      if (options.disableScroll) event.preventDefault();

      var touches = event.touches[0];

      // measure change in x and y
      delta = {
        x: touches.pageX - start.x,
        y: touches.pageY - start.y
      }

      // determine if scrolling test has run - one time test
      if (typeof isScrolling == 'undefined') {
        isScrolling = !!(isScrolling || Math.abs(delta.x) < Math.abs(delta.y));
      }

      // if user is not trying to scroll vertically
      if (!isScrolling) {

        // prevent native scrolling
        event.preventDefault();

        // stop slideshow
        stop();

        // increase resistance if first or last slide
        if (options.continuous) { // we don't add resistance at the end

          translate(circle(index - 1), delta.x + slidePos[circle(index - 1)], 0);
          translate(index, delta.x + slidePos[index], 0);
          translate(circle(index + 1), delta.x + slidePos[circle(index + 1)], 0);

        } else {

          delta.x =
            delta.x /
            ((!index && delta.x > 0 // if first slide and sliding left
                ||
                index == slides.length - 1 // or if last slide and sliding right
                &&
                delta.x < 0 // and if sliding at all
              ) ?
              (Math.abs(delta.x) / width + 1) // determine resistance level
              :
              1); // no resistance if false

          // translate 1:1
          translate(index - 1, delta.x + slidePos[index - 1], 0);
          translate(index, delta.x + slidePos[index], 0);
          translate(index + 1, delta.x + slidePos[index + 1], 0);
        }

      }

    },
    end: function(event) {

      // measure duration
      var duration = +new Date - start.time;

      // determine if slide attempt triggers next/prev slide
      var isValidSlide =
        Number(duration) < 250 // if slide duration is less than 250ms
        &&
        Math.abs(delta.x) > 20 // and if slide amt is greater than 20px
        ||
        Math.abs(delta.x) > width / 2; // or if slide amt is greater than half the width

      // determine if slide attempt is past start and end
      var isPastBounds = !index && delta.x > 0 // if first slide and slide amt is greater than 0
        ||
        index == slides.length - 1 && delta.x < 0; // or if last slide and slide amt is less than 0

      if (options.continuous) isPastBounds = false;

      // determine direction of swipe (true:right, false:left)
      var direction = delta.x < 0;

      // if not scrolling vertically
      if (!isScrolling) {

        if (isValidSlide && !isPastBounds) {

          if (direction) {

            if (options.continuous) { // we need to get the next in this direction in place

              move(circle(index - 1), -width, 0);
              move(circle(index + 2), width, 0);

            } else {
              move(index - 1, -width, 0);
            }

            move(index, slidePos[index] - width, speed);
            move(circle(index + 1), slidePos[circle(index + 1)] - width, speed);
            index = circle(index + 1);

          } else {
            if (options.continuous) { // we need to get the next in this direction in place

              move(circle(index + 1), width, 0);
              move(circle(index - 2), -width, 0);

            } else {
              move(index + 1, width, 0);
            }

            move(index, slidePos[index] + width, speed);
            move(circle(index - 1), slidePos[circle(index - 1)] + width, speed);
            index = circle(index - 1);

          }

          options.callback && options.callback(index, slides[index]);

        } else {

          if (options.continuous) {

            move(circle(index - 1), -width, speed);
            move(index, 0, speed);
            move(circle(index + 1), width, speed);

          } else {

            move(index - 1, -width, speed);
            move(index, 0, speed);
            move(index + 1, width, speed);
          }

        }

      }

      // kill touchmove and touchend event listeners until touchstart called again
      element.removeEventListener('touchmove', events, false)
      element.removeEventListener('touchend', events, false)

    },
    transitionEnd: function(event) {

      if (parseInt(event.target.getAttribute('data-index'), 10) == index) {

        if (delay) begin();

        options.transitionEnd && options.transitionEnd.call(event, index, slides[index]);

      }

    }

  }

  // trigger setup
  setup();

  // start auto slideshow if applicable
  if (delay) begin();


  // add event listeners
  if (browser.addEventListener) {

    // set touchstart event on element
    if (browser.touch) element.addEventListener('touchstart', events, false);

    if (browser.transitions) {
      element.addEventListener('webkitTransitionEnd', events, false);
      element.addEventListener('msTransitionEnd', events, false);
      element.addEventListener('oTransitionEnd', events, false);
      element.addEventListener('otransitionend', events, false);
      element.addEventListener('transitionend', events, false);
    }

    // set resize event on window
    window.addEventListener('resize', events, false);

  } else {

    window.onresize = function() {
      setup()
    }; // to play nice with old IE

  }

  // expose the Swipe API
  return {
    setup: function() {

      setup();

    },
    slide: function(to, speed) {

      // cancel slideshow
      stop();

      slide(to, speed);

    },
    prev: function() {

      // cancel slideshow
      stop();

      prev();

    },
    next: function() {

      // cancel slideshow
      stop();

      next();

    },
    stop: function() {

      // cancel slideshow
      stop();

    },
    getPos: function() {

      // return current index position
      return index;

    },
    getNumSlides: function() {

      // return total number of slides
      return length;
    },
    kill: function() {

      // cancel slideshow
      stop();

      // reset element
      element.style.width = '';
      element.style.left = '';

      // reset slides
      var pos = slides.length;
      while (pos--) {

        var slide = slides[pos];
        slide.style.width = '';
        slide.style.left = '';

        if (browser.transitions) translate(pos, 0, 0);

      }

      // removed event listeners
      if (browser.addEventListener) {

        // remove current event listeners
        element.removeEventListener('touchstart', events, false);
        element.removeEventListener('webkitTransitionEnd', events, false);
        element.removeEventListener('msTransitionEnd', events, false);
        element.removeEventListener('oTransitionEnd', events, false);
        element.removeEventListener('otransitionend', events, false);
        element.removeEventListener('transitionend', events, false);
        window.removeEventListener('resize', events, false);

      } else {

        window.onresize = null;

      }

    }
  }

}


if (window.jQuery || window.Zepto) {
  (function($) {
    $.fn.Swipe = function(params) {
      return this.each(function() {
        $(this).data('Swipe', new Swipe($(this)[0], params));
      });
    }
  })(window.jQuery || window.Zepto)
}

＆＃13;

ul,
li {
  display: inline-block;
  list-style: none
}

li,
.swipeBtn {
  cursor: pointer
}

li+li {
  margin-left: 10px
}

li::before {
  content: '●';
  color: grey
}

.dot_select::before {
  color: blue
}

#mySwipe {
  overflow: hidden
}

＆＃13;

＆＃13;

＆＃13;

Answer 2

您不需要var prevDot。您可以使用index：

正确播放

  $(".swipeDot li").removeClass("dot_select")
  .eq(index).addClass("dot_select");

请参阅代码段：

function init() {

  var elem = document.getElementById('mySwipe');
  window.mySwipe = Swipe(elem, {
    // startSlide: 4,
    // auto: 3000,
    // continuous: true,
    // disableScroll: true,
    // stopPropagation: true,
    // callback: function(index, element) {},
    transitionEnd: function(index, element) {
      $(".swipeDot li").removeClass("dot_select")
      .eq(index).addClass("dot_select");
    }
  });

  //$(".swipe-wrap").find("div").eq(2).find("span").css({backgroundImage:"url('../images/p006_img_2.png')"})
  $("#prevBtn").click(function() {
    window.mySwipe.prev();
  });

  $("#nextBtn").click(function() {
    window.mySwipe.next();
  });

  $(".swipeDot li").each(function(index) {
    $(this).attr("slideIndex", index);
  });

  $(".swipeDot li").click(function() {
    var slideIndex = $(this).attr("slideIndex");
    window.mySwipe.slide(slideIndex);
  });

}



$(document).ready(init);




function Swipe(container, options) {
  console.log(container);
  "use strict";

  // utilities
  var noop = function() {}; // simple no operation function
  var offloadFn = function(fn) {
    setTimeout(fn || noop, 0)
  }; // offload a functions execution

  // check browser capabilities
  var browser = {
    addEventListener: !!window.addEventListener,
    touch: ('ontouchstart' in window) || window.DocumentTouch && document instanceof DocumentTouch,
    transitions: (function(temp) {
      var props = ['transitionProperty', 'WebkitTransition', 'MozTransition', 'OTransition', 'msTransition'];
      for (var i in props)
        if (temp.style[props[i]] !== undefined) return true;
      return false;
    })(document.createElement('swipe'))
  };

  // quit if no root element
  if (!container) return;
  var element = container.children[0];
  var slides, slidePos, width, length;
  options = options || {};
  var index = parseInt(options.startSlide, 10) || 0;
  var speed = options.speed || 300;
  options.continuous = options.continuous !== undefined ? options.continuous : true;

  function setup() {

    // cache slides
    slides = element.children;
    length = slides.length;

    // set continuous to false if only one slide
    if (slides.length < 2) options.continuous = false;



    //special case if two slides
    if (browser.transitions && options.continuous && slides.length < 3) {
      element.appendChild(slides[0].cloneNode(true));
      element.appendChild(element.children[1].cloneNode(true));

      slides = element.children;
    }

    // create an array to store current positions of each slide
    slidePos = new Array(slides.length);

    // determine width of each slide
    width = container.offsetWidth;

    element.style.width = (slides.length * width) + 'px';

    // stack elements
    var pos = slides.length;

    while (pos--) {

      var slide = slides[pos];

      slide.style.width = width + 'px';

      slide.setAttribute('data-index', pos);

      if (browser.transitions) {
        slide.style.left = (pos * -width) + 'px';
        move(pos, index > pos ? -width : (index < pos ? width : 0), 0);
      }

    }

    // reposition elements before and after index
    if (options.continuous && browser.transitions) {
      move(circle(index - 1), -width, 0);
      move(circle(index + 1), width, 0);
    }

    if (!browser.transitions) element.style.left = (index * -width) + 'px';

    container.style.visibility = 'visible';

  }

  function prev() {

    if (options.continuous) slide(index - 1);
    else if (index) slide(index - 1);

  }

  function next() {

    if (options.continuous) slide(index + 1);
    else if (index < slides.length - 1) slide(index + 1);

  }

  function circle(index) {

    // a simple positive modulo using slides.length
    return (slides.length + (index % slides.length)) % slides.length;

  }

  function slide(to, slideSpeed) {

    // do nothing if already on requested slide
    if (index == to) return;

    if (browser.transitions) {

      var direction = Math.abs(index - to) / (index - to); // 1: backward, -1: forward

      // get the actual position of the slide
      if (options.continuous) {
        var natural_direction = direction;
        direction = -slidePos[circle(to)] / width;

        // if going forward but to < index, use to = slides.length + to
        // if going backward but to > index, use to = -slides.length + to
        if (direction !== natural_direction) to = -direction * slides.length + to;

      }

      var diff = Math.abs(index - to) - 1;

      // move all the slides between index and to in the right direction
      while (diff--) move(circle((to > index ? to : index) - diff - 1), width * direction, 0);

      to = circle(to);

      move(index, width * direction, slideSpeed || speed);
      move(to, 0, slideSpeed || speed);

      if (options.continuous) move(circle(to - direction), -(width * direction), 0); // we need to get the next in place

    } else {

      to = circle(to);
      animate(index * -width, to * -width, slideSpeed || speed);
      //no fallback for a circular continuous if the browser does not accept transitions
    }

    index = to;
    offloadFn(options.callback && options.callback(index, slides[index]));
  }

  function move(index, dist, speed) {

    translate(index, dist, speed);
    slidePos[index] = dist;

  }

  function translate(index, dist, speed) {

    var slide = slides[index];
    var style = slide && slide.style;

    if (!style) return;

    style.webkitTransitionDuration =
      style.MozTransitionDuration =
      style.msTransitionDuration =
      style.OTransitionDuration =
      style.transitionDuration = speed + 'ms';

    style.webkitTransform = 'translate(' + dist + 'px,0)' + 'translateZ(0)';
    style.msTransform =
      style.MozTransform =
      style.OTransform = 'translateX(' + dist + 'px)';

  }

  function animate(from, to, speed) {

    // if not an animation, just reposition
    if (!speed) {

      element.style.left = to + 'px';
      return;

    }

    var start = +new Date;

    var timer = setInterval(function() {

      var timeElap = +new Date - start;

      if (timeElap > speed) {

        element.style.left = to + 'px';

        if (delay) begin();

        options.transitionEnd && options.transitionEnd.call(event, index, slides[index]);

        clearInterval(timer);
        return;

      }

      element.style.left = (((to - from) * (Math.floor((timeElap / speed) * 100) / 100)) + from) + 'px';

    }, 4);

  }

  // setup auto slideshow
  var delay = options.auto || 0;
  var interval;

  function begin() {

    interval = setTimeout(next, delay);

  }

  function stop() {

    delay = 0;
    clearTimeout(interval);

  }


  // setup initial vars
  var start = {};
  var delta = {};
  var isScrolling;

  // setup event capturing
  var events = {

    handleEvent: function(event) {

      switch (event.type) {
        case 'touchstart':
          this.start(event);
          break;
        case 'touchmove':
          this.move(event);
          break;
        case 'touchend':
          offloadFn(this.end(event));
          break;
        case 'webkitTransitionEnd':
        case 'msTransitionEnd':
        case 'oTransitionEnd':
        case 'otransitionend':
        case 'transitionend':
          offloadFn(this.transitionEnd(event));
          break;
        case 'resize':
          offloadFn(setup);
          break;
      }

      if (options.stopPropagation) event.stopPropagation();

    },
    start: function(event) {

      var touches = event.touches[0];

      // measure start values
      start = {

        // get initial touch coords
        x: touches.pageX,
        y: touches.pageY,

        // store time to determine touch duration
        time: +new Date

      };

      // used for testing first move event
      isScrolling = undefined;

      // reset delta and end measurements
      delta = {};

      // attach touchmove and touchend listeners
      element.addEventListener('touchmove', this, false);
      element.addEventListener('touchend', this, false);

    },
    move: function(event) {

      // ensure swiping with one touch and not pinching
      if (event.touches.length > 1 || event.scale && event.scale !== 1) return

      if (options.disableScroll) event.preventDefault();

      var touches = event.touches[0];

      // measure change in x and y
      delta = {
        x: touches.pageX - start.x,
        y: touches.pageY - start.y
      }

      // determine if scrolling test has run - one time test
      if (typeof isScrolling == 'undefined') {
        isScrolling = !!(isScrolling || Math.abs(delta.x) < Math.abs(delta.y));
      }

      // if user is not trying to scroll vertically
      if (!isScrolling) {

        // prevent native scrolling
        event.preventDefault();

        // stop slideshow
        stop();

        // increase resistance if first or last slide
        if (options.continuous) { // we don't add resistance at the end

          translate(circle(index - 1), delta.x + slidePos[circle(index - 1)], 0);
          translate(index, delta.x + slidePos[index], 0);
          translate(circle(index + 1), delta.x + slidePos[circle(index + 1)], 0);

        } else {

          delta.x =
            delta.x /
            ((!index && delta.x > 0 // if first slide and sliding left
                ||
                index == slides.length - 1 // or if last slide and sliding right
                &&
                delta.x < 0 // and if sliding at all
              ) ?
              (Math.abs(delta.x) / width + 1) // determine resistance level
              :
              1); // no resistance if false

          // translate 1:1
          translate(index - 1, delta.x + slidePos[index - 1], 0);
          translate(index, delta.x + slidePos[index], 0);
          translate(index + 1, delta.x + slidePos[index + 1], 0);
        }

      }

    },
    end: function(event) {

      // measure duration
      var duration = +new Date - start.time;

      // determine if slide attempt triggers next/prev slide
      var isValidSlide =
        Number(duration) < 250 // if slide duration is less than 250ms
        &&
        Math.abs(delta.x) > 20 // and if slide amt is greater than 20px
        ||
        Math.abs(delta.x) > width / 2; // or if slide amt is greater than half the width

      // determine if slide attempt is past start and end
      var isPastBounds = !index && delta.x > 0 // if first slide and slide amt is greater than 0
        ||
        index == slides.length - 1 && delta.x < 0; // or if last slide and slide amt is less than 0

      if (options.continuous) isPastBounds = false;

      // determine direction of swipe (true:right, false:left)
      var direction = delta.x < 0;

      // if not scrolling vertically
      if (!isScrolling) {

        if (isValidSlide && !isPastBounds) {

          if (direction) {

            if (options.continuous) { // we need to get the next in this direction in place

              move(circle(index - 1), -width, 0);
              move(circle(index + 2), width, 0);

            } else {
              move(index - 1, -width, 0);
            }

            move(index, slidePos[index] - width, speed);
            move(circle(index + 1), slidePos[circle(index + 1)] - width, speed);
            index = circle(index + 1);

          } else {
            if (options.continuous) { // we need to get the next in this direction in place

              move(circle(index + 1), width, 0);
              move(circle(index - 2), -width, 0);

            } else {
              move(index + 1, width, 0);
            }

            move(index, slidePos[index] + width, speed);
            move(circle(index - 1), slidePos[circle(index - 1)] + width, speed);
            index = circle(index - 1);

          }

          options.callback && options.callback(index, slides[index]);

        } else {

          if (options.continuous) {

            move(circle(index - 1), -width, speed);
            move(index, 0, speed);
            move(circle(index + 1), width, speed);

          } else {

            move(index - 1, -width, speed);
            move(index, 0, speed);
            move(index + 1, width, speed);
          }

        }

      }

      // kill touchmove and touchend event listeners until touchstart called again
      element.removeEventListener('touchmove', events, false)
      element.removeEventListener('touchend', events, false)

    },
    transitionEnd: function(event) {

      if (parseInt(event.target.getAttribute('data-index'), 10) == index) {

        if (delay) begin();

        options.transitionEnd && options.transitionEnd.call(event, index, slides[index]);

      }

    }

  }

  // trigger setup
  setup();

  // start auto slideshow if applicable
  if (delay) begin();


  // add event listeners
  if (browser.addEventListener) {

    // set touchstart event on element
    if (browser.touch) element.addEventListener('touchstart', events, false);

    if (browser.transitions) {
      element.addEventListener('webkitTransitionEnd', events, false);
      element.addEventListener('msTransitionEnd', events, false);
      element.addEventListener('oTransitionEnd', events, false);
      element.addEventListener('otransitionend', events, false);
      element.addEventListener('transitionend', events, false);
    }

    // set resize event on window
    window.addEventListener('resize', events, false);

  } else {

    window.onresize = function() {
      setup()
    }; // to play nice with old IE

  }

  // expose the Swipe API
  return {
    setup: function() {

      setup();

    },
    slide: function(to, speed) {

      // cancel slideshow
      stop();

      slide(to, speed);

    },
    prev: function() {

      // cancel slideshow
      stop();

      prev();

    },
    next: function() {

      // cancel slideshow
      stop();

      next();

    },
    stop: function() {

      // cancel slideshow
      stop();

    },
    getPos: function() {

      // return current index position
      return index;

    },
    getNumSlides: function() {

      // return total number of slides
      return length;
    },
    kill: function() {

      // cancel slideshow
      stop();

      // reset element
      element.style.width = '';
      element.style.left = '';

      // reset slides
      var pos = slides.length;
      while (pos--) {

        var slide = slides[pos];
        slide.style.width = '';
        slide.style.left = '';

        if (browser.transitions) translate(pos, 0, 0);

      }

      // removed event listeners
      if (browser.addEventListener) {

        // remove current event listeners
        element.removeEventListener('touchstart', events, false);
        element.removeEventListener('webkitTransitionEnd', events, false);
        element.removeEventListener('msTransitionEnd', events, false);
        element.removeEventListener('oTransitionEnd', events, false);
        element.removeEventListener('otransitionend', events, false);
        element.removeEventListener('transitionend', events, false);
        window.removeEventListener('resize', events, false);

      } else {

        window.onresize = null;

      }

    }
  }

}


if (window.jQuery || window.Zepto) {
  (function($) {
    $.fn.Swipe = function(params) {
      return this.each(function() {
        $(this).data('Swipe', new Swipe($(this)[0], params));
      });
    }
  })(window.jQuery || window.Zepto)
}

ul,
li {
  display: inline-block;
  list-style: none
}

li,
.swipeBtn {
  cursor: pointer
}

li+li {
  margin-left: 10px
}

li::before {
  content: '●';
  color: grey
}

.dot_select::before {
  color: blue
}

#mySwipe {
  overflow: hidden
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="swipeBtn hotspot hspot cElement" id="prevBtn">&#x2770;</div>
<div id='mySwipe' style='width:600px;margin:0 auto' class='swipe hotspot hspot cElement'>
  <div class='swipe-wrap'>
    <div><span id="slide1">---- SLIDE1 ----</span></div>
    <div><span id="slide2">---- SLIDE2 ----</span></div>
    <div><span id="slide3">---- SLIDE3 ----</span></div>
  </div>
</div>
<div class="swipeBtn hotspot hspot cElement" id="nextBtn">&#x2771;</div>
<ul class="swipeDot">
  <li class="dot_select"></li>
  <li></li>
  <li></li>
</ul>