顾名思义:事件委托就是利用冒泡原理,将事件加在父元素或祖元素上,触发执行效果
var btn6 = document.getElementById("btn6");
document.onclick = function(event){
event = event || window.event;
var target = event.target || event.srcElement;
if(target == btn6){
alert(btn5.value);
}
}
<ul id="list">
<li id="item1" >item1</li>
<li id="item2" >item2</li>
<li id="item3" >item3</li>
</ul>
var item1 = document.getElementById("item1");
var item2 = document.getElementById("item2");
var item3 = document.getElementById("item3");
document.addEventListener("click",function(event){
var target = event.target;
if(target == item1){
alert("hello item1");
}else if(target == item2){
alert("hello item2");
}else if(target == item3){
alert("hello item3");
}
})
<ul id="list">
<li id="item1" >item1</li>
<li id="item2" >item2</li>
<li id="item3" >item3</li>
</ul>
var list = document.getElementById("list");
document.addEventListener("click",function(event){
var target = event.target;
if(target.nodeName == "LI"){
alert(target.innerHTML);
}
})
var node=document.createElement("li");
var textnode=document.createTextNode("item4");
node.appendChild(textnode);
list.appendChild(node);