Question

让我们从一些事件监听器开始：

window.addEventListener('scroll', function (e) {
    console.log('scroll', e);
});
window.addEventListener('touchstart', function (e) {
    console.log('touchstart', e);
});
window.addEventListener('touchmove', function (e) {
    console.log('touchmove', e);
});
window.addEventListener('touchend', function (e) {
    console.log('touchend', e);
});

我需要以编程方式触摸位置{pageX: 0, pageY: 0}的文档，将其移至{pageX: 0, pageY: 100}并结束触摸事件。

为此，我将构建一个辅助函数TouchEvent，它将触发指定元素上的触摸事件。

/**
 * @see https://gist.github.com/sstephenson/448808
 * @see https://developer.apple.com/library/iad/documentation/UserExperience/Reference/TouchEventClassReference/TouchEvent/TouchEvent.html
 * @see http://stackoverflow.com/questions/18059860/manually-trigger-touch-event
 */
function touchEvent (element, type, identifier, pageX, pageY) {
    var e,
        touch,
        touches,
        targetTouches,
        changedTouches;

    touch = document.createTouch(window, element, identifier, pageX, pageY, pageX, pageY);

    if (type == 'touchend') {
        touches = document.createTouchList();
        targetTouches = document.createTouchList();
        changedTouches = document.createTouchList(touch);
    } else {
        touches = document.createTouchList(touch);
        targetTouches = document.createTouchList(touch);
        changedTouches = document.createTouchList(touch);
    }

    e = document.createEvent('TouchEvent');
    e.initTouchEvent(type, true, true, window, null, 0, 0, 0, 0, false, false, false, false, touches, targetTouches, changedTouches, 1, 0);

    window.dispatchEvent(e);
};

我将确保加载文档并发送代表先前商定的方案的触摸事件。

document.addEventListener('DOMContentLoaded', function() {
    var identifier = new Date().getTime(),
        element = document,
        i = 0;

    touchEvent(element, 'touchstart', identifier, 0, 0);
    while (i++ < 100) {
        touchEvent(element, 'touchmove', identifier, 0, i);
    }
    touchEvent(element, 'touchend', identifier, 0, i);
});

预计会触发touchstart，touchmove和touchend事件。出人意料的是，scroll事件尚未触发，实际触及＆＃34;该文件未反映在当前文件中。

＆＃13;

window.addEventListener('scroll', function (e) {
    console.log('scroll', e);
});
window.addEventListener('resize', function (e) {
    console.log('resize', e);
});
window.addEventListener('touchstart', function (e) {
    console.log('touchstart', e);
});
window.addEventListener('touchmove', function (e) {
    console.log('touchmove', e);
});
window.addEventListener('touchend', function (e) {
    console.log('touchend', e);
});

/**
 * @see https://gist.github.com/sstephenson/448808
 * @see https://developer.apple.com/library/iad/documentation/UserExperience/Reference/TouchEventClassReference/TouchEvent/TouchEvent.html
 * @see http://stackoverflow.com/questions/18059860/manually-trigger-touch-event
 */
function touchEvent (element, type, identifier, pageX, pageY) {
    var e,
        touch,
        touches,
        targetTouches,
        changedTouches;
  
    if (!document.createTouch) {
        throw new Error('This will work only in Safari browser.');
    }

    touch = document.createTouch(window, element, identifier, pageX, pageY, pageX, pageY);
    
    if (type == 'touchend') {
        touches = document.createTouchList();
        targetTouches = document.createTouchList();
        changedTouches = document.createTouchList(touch);
    } else {
        touches = document.createTouchList(touch);
        targetTouches = document.createTouchList(touch);
        changedTouches = document.createTouchList(touch);
    }

    e = document.createEvent('TouchEvent');
    e.initTouchEvent(type, true, true, window, null, 0, 0, 0, 0, false, false, false, false, touches, targetTouches, changedTouches, 1, 0);

    window.dispatchEvent(e);
};

document.addEventListener('DOMContentLoaded', function() {
    var identifier = new Date().getTime(),
        element = document,
        i = 0;

    touchEvent(element, 'touchstart', identifier, 0, 0);
    while (i++ < 100) {
        touchEvent(element, 'touchmove', identifier, 0, i);
    }
    touchEvent(element, 'touchend', identifier, 0, i);
});

＆＃13;

#playground {
    background: #999; height: 5000px;
}

＆＃13;

<div id="playground"></div>

＆＃13;

我的设置缺少什么使浏览器将触摸事件解释为最终用户发布的触摸事件？从本质上讲，我期待浏览器滚动以响应一系列以编程方式触发的触摸开始，移动和结束事件。

Answer 1

我不确定我是否正确理解了你的问题，但如果你开始触摸页面顶部并向下拖动你试图将页面滚动到顶部并且它已经存在，那么为什么滚动会触发。也许从位置{pageX: 0, pageY: 100}开始，到{pageX: 0, pageY: 0}结束，然后查看它是否仍无效。

问候，KJ。

如何触发触摸事件？

1 个答案: