js模拟触发事件

window.onload = function () {

    var bot = document.getElementById(\'bot\');
    bot.addEventListener(\'touchstart\', function () {
        alert(\'touchstart\');
    });
    
    creatTouchstartEventAndDispatch(bot);
    
    function creatTouchstartEventAndDispatch (el) {
        var event = document.createEvent(\'Events\');
        event.initEvent(\'touchstart\', true, true);
        el.dispatchEvent(event);
    }
    
}

先用 createEvent 创建模拟事件，再用 dispatchEvent 触发