Question

我有这个孩子绘画应用程序，它使用鼠标事件在图像上绘画。但是，我需要将鼠标事件转换为触摸，以便它可以在ipad上工作。有人可以解释一下如何做到这一点。我的应用代码与此示例代码http://cool-php-tutorials.blogspot.co.uk/2011/05/simple-html5-drawing-app-with-saving.html非常相似。

P.S我对javascript的了解并不高级，所以如果你能告诉我工作代码或示例将是一个很大的帮助

执行鼠标事件的代码如下。请将此功能从鼠标转换为触摸..请在2天后我被困在这里..：|

var clickX = new Array();
var clickY = new Array();
var clickDrag = new Array();

// binding events to the canvas
$('#drawingCanvas').mousedown(function(e){
  var mouseX = e.pageX - this.offsetLeft;
  var mouseY = e.pageY - this.offsetTop;

  paint = true; // start painting
  addClick(e.pageX - this.offsetLeft, e.pageY - this.offsetTop);

  // always call redraw
  redraw();
});

$('#drawingCanvas').mousemove(function(e){
  if(paint){
    addClick(e.pageX - this.offsetLeft, e.pageY - this.offsetTop, true);
    redraw();
  }
});

// when mouse is released, stop painting, clear the arrays with dots
$('#drawingCanvas').mouseup(function(e){
  paint = false;

  clickX = new Array();
  clickY = new Array();
  clickDrag = new Array();
});

// stop painting when dragged out of the canvas
$('#drawARobot').mouseleave(function(e){
  paint = false;
});


// The function pushes to the three dot arrays
function addClick(x, y, dragging)
{
  clickX.push(x);
  clickY.push(y);
  clickDrag.push(dragging);
}



// this is where actual drawing happens
// we add dots to the canvas


function redraw(){

  for(var i=0; i < clickX.length; i++)
  {  
    context.beginPath();
    if(clickDrag[i] && i){
      context.moveTo(clickX[i-1], clickY[i-1]);
     }else{
       context.moveTo(clickX[i]-1, clickY[i]);
     }
     context.lineTo(clickX[i], clickY[i]);
     context.closePath();
     context.stroke();
  }
}

Answer 1

你可以这样映射：

$('#drawingCanvas').bind("mousedown touchstart", function(e){

$('#drawingCanvas').bind("mousemove touchmove", function(e){

$('#drawingCanvas').bind("mouseup touchend", function(e){

而不是在需要时微调代码。

Answer 2

试试这个：

注意：您需要jquery库。

<强> touchmouse.js

(function() {

    /* == GLOBAL DECLERATIONS == */
    TouchMouseEvent = {
        DOWN: "touchmousedown",
        UP: "touchmouseup",
        MOVE: "touchmousemove"
    }

    /* == EVENT LISTENERS == */
    var onMouseEvent = function(event) {
        var type;

        switch (event.type) {
            case "mousedown": type = TouchMouseEvent.DOWN; break;
            case "mouseup":   type = TouchMouseEvent.UP;   break;
            case "mousemove": type = TouchMouseEvent.MOVE; break;
            default: 
                return;
        }

        var touchMouseEvent = normalizeEvent(type, event, event.pageX, event.pageY);      
        $(event.target).trigger(touchMouseEvent); 
    }

    var onTouchEvent = function(event) {
        var type;

        switch (event.type) {
            case "touchstart": type = TouchMouseEvent.DOWN; break;
            case "touchend":   type = TouchMouseEvent.UP;   break;
            case "touchmove":  type = TouchMouseEvent.MOVE; break;
            default: 
                return;
        }

        var touch = event.originalEvent.touches[0];
        var touchMouseEvent;

        if (type == TouchMouseEvent.UP) 
            touchMouseEvent = normalizeEvent(type, event, null, null);
        else 
            touchMouseEvent = normalizeEvent(type, event, touch.pageX, touch.pageY);

        $(event.target).trigger(touchMouseEvent); 
    }

    /* == NORMALIZE == */
    var normalizeEvent = function(type, original, x, y) {
        return $.Event(type, {
            pageX: x,
            pageY: y,
            originalEvent: original
        });
    }

    /* == LISTEN TO ORIGINAL EVENT == */
    var jQueryDocument = $(document);

    if ("ontouchstart" in window) {
        jQueryDocument.on("touchstart", onTouchEvent);
        jQueryDocument.on("touchmove", onTouchEvent);
        jQueryDocument.on("touchend", onTouchEvent); 
    } else {
        jQueryDocument.on("mousedown", onMouseEvent);
        jQueryDocument.on("mouseup", onMouseEvent);
        jQueryDocument.on("mousemove", onMouseEvent);
    }

})();

html页面（index.html）

<!DOCTYPE html>
<html>
    <head>
        <title>touch</title>

        <meta http-equiv="Content-Type" content="text/html;charset=utf8" />
        <meta name="author" content="AUTHOR" />
        <meta name="keyword" content="KEYWORD" />
        <meta name="description" content="DESCRIPTION" />
        <script type="text/javascript" src="jquery.min.js"></script><!-- Please Download the jquery library -->
        <script type="text/javascript" src="touchmouse.js"></script>
        <script type="text/javascript">
        $(function(){
                var startdrag= false;
             $("#a").on(TouchMouseEvent.DOWN, function(){
                startdrag= true;
                move();

             });
             function move(){

                 $("#a").on(TouchMouseEvent.MOVE, function(e){
                    if(startdrag){
                    $(this).css('left',(e.pageX-50)) ;
                    $(this).css('top',(e.pageY-50));
                 }
                 });

            }
             $("#a").on(TouchMouseEvent.UP, function(e){
                startdrag= false;

             });

        });
        </script>

    </head>
    <body>
        <div id ="a" style="display:block;position:absolute;width:100px;height:100px;background:red;" ></div>
    </body>
</html>

在Android手机上这对我有用。

Answer 3

鼠标和触摸事件的问题在于它们没有相同的api，

所以你需要规范化api以同时拥有鼠标和触摸输入。

有一些解决方案，如：

http://eightmedia.github.io/hammer.js/

锤子代码非常易于使用：

var hamme = $("#myCanvas").hammer();

hammer.on("touch", function(e){     
   e.gesture.center.pageX;
    // ..
});

hammer.on("drag", function(e){
    e.gesture.center.pageX
   //..
})

Answer 4

您也可以尝试 - jQuery UI Touch Punch

Click Here

鼠标事件触摸事件以获得ipad兼容性

4 个答案: