欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  IT编程

JS基础——事件操作总结

程序员文章站 2024-01-18 16:04:58
通用事件绑定 function bindEvent(elem,type,fn) { elem.addEventListener(type,fn); } let a =document.getElementById('a'); bindEvent(a,'click',function(e){ e.pr ......

通用事件绑定

 
function bindEvent(elem,type,fn) {
  elem.addEventListener(type,fn);
}
let a =document.getElementById('a');
bindEvent(a,'click',function(e){
  e.preventDefault() //阻止浏览器默认行为,防止调转
  alert(‘clicked’);
}) 

事件冒泡

<body>
<div>
<p id ="p1">激活</p>
<p id ="p2">取消</p>
<p id ="p3">取消</p>
</div>
<div>
<p id ="p4">取消</p>
<p id ="p5">取消</p>
</div>
</body>
let body =document.body
let p1 =document.getElementById('p1');
bindEvent(p1,'click',function(e){
    e.stopPropagation(); //阻止事件冒泡
    alert('激活')
})
bindEvent(body,'click',function(e){
    alert('取消')
})

事件代理 

<body>
<div id="div1">
<p id ="p1">激活</p>
<p id ="p2">取消</p>
<p id ="p3">确认</p>
</div>
</body>

 

let body =document.body
let div1 =document.getElementById('div1');
bindEvent(div1,'click',function(e){
        const target =e.target;
        if(target.nodeName === 'A') {  //判断是否是a标签
alert('target.innerHTML')
}
}) 

事件绑定函数(完善)

function bindEvent(elem,type,selector,fn) {
if(fn == null){
fn = selector;
selector = null;
}
elem.addEventListener(type,function(e){
if(selector){
const target= e.target
if(target.matches(seletor)){
fn.call(target, e)
}
}else {
fn(e);
}
});
}