事件冒泡

if(window.event){
    //cancelBubble的字面意思是取消冒泡
    //如果事件句柄想阻止事件传播到包容对象，必须把该属性设为 true。
    e.cancelBubble = true;
} else {
    e.preventDefault(); //方法取消事件的默认动作
    e.stopPropagation(); //stopPropagation的字面意思是停止传播。
}

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en"> <head> <title>test-event-bubble</title> <meta http-equiv="Content-Type" content="text/html;charset=UTF-8" /> <style type="text/css"> #test-wrap div{border:1px solid #ccc;padding:5px 10px 10px;cursor:pointer;} #test2{margin-top:15px;} </style> </head> <body> <div id="test-wrap"> <h3>事件冒泡</h3> <div id="test"> test <div id="sub"> sub <div id="on">this is on</div> </div> </div> <h3>没有冒泡</h3> <div id="test2"> test2 <div id="sub2"> sub2 <div id="on2">this is on2</div> </div> </div> </div> <script type="text/javascript"> var $ = function(){ return document.getElementById(arguments[0])}; var test = $('test'), sub = $('sub'), on = $('on'), test2 = $('test2'), sub2 = $('sub2'), on2 = $('on2'); var can = function(event){ var e = event || window.event; if(window.event){ //cancelBubble的字面意思是取消冒泡 //如果事件句柄想阻止事件传播到包容对象，必须把该属性设为 true。 e.cancelBubble = true; } else { e.preventDefault(); //方法取消事件的默认动作 e.stopPropagation(); //stopPropagation的字面意思是停止传播。 } } on.onmouseover = function(event){ this.style.border = '2px dashed red'; } sub.onmouseover = function(event){ this.style.border = '2px dashed green'; } test.onmouseover = function(event){ this.style.border = '2px dashed blue'; } on2.onmouseover = function(event){ can(event); this.style.border = '2px dashed red'; } sub2.onmouseover = function(event){ can(event); this.style.border = '2px dashed green'; } test2.onmouseover = function(event){ can(event); this.style.border = '2px dashed blue'; } on.onmouseout = sub.onmouseout = test.onmouseout = on2.onmouseout = sub2.onmouseout = test2.onmouseout = function(){ this.style.border = '1px solid #ccc'; } </script> </body> </html>