<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>3种用tagname和id获取元素的方法</title>
<style>
body{
margin: 0;
}
ul{
margin: 0;
padding: 0;
list-style: none;
}
h1{
margin: 0;
}
</style>
</head>
<body>
<div class="box" id="box">
<h1 class="box-tit">分类名称</h1>
<ul class="box-list" id="box-list">
<li class="box-listI">
<input class="box-listI-input">
<button>保存</button>
<button>取消</button>
</li>
<li class="box-listI">
<input class="box-listI-input">
<button>保存</button>
<button>取消</button>
</li>
<li class="box-listI">
<input class="box-listI-input">
<button>保存</button>
<button>取消</button>
</li>
</ul>
</div>
<script>
//[1]整体法，先获取所有的元素，再通过ai+-b的方法来算出需要的元素
var oList = document.getElementById('box-list');
var aInput = oList.getElementsByTagName('input');
var aBtn =oList.getElementsByTagName('button'); for(var i = 0; i < aBtn.length; i++){
aBtn[i].index = i;
}
for(var i = 0; i < aInput.length; i++){
//确定按钮
aBtn[2*i].onclick = function(){
aInput[this.index/2].disabled = true;
}
//取消按钮
aBtn[2*i+1].onclick = function(){
aInput[(this.index-1)/2].disabled = false;
aInput[(this.index-1)/2].value = '';
console.log(1);
}
}
//[2]数组法，在全局环境下建立空数组，遇到需要循环的结构时，在循环中获取元素，并放入数组
var oList = document.getElementById('box-list');
var aIn = oList.getElementsByTagName('li');
var aInput = [];
var aBtnY = [];
var aBtnX = [];
for(var i = 0; i < aIn.length; i++){
aInput[i] = aIn[i].getElementsByTagName('input')[0];
aBtnY[i] = aIn[i].getElementsByTagName('button')[0];
aBtnX[i] = aIn[i].getElementsByTagName('button')[1]; aBtnY[i].index = aBtnX[i].index = i;
//确定按钮
aBtnY[i].onclick = function(){
aInput[this.index].disabled = true;
}
//取消按钮
aBtnX[i].onclick = function(){
aInput[this.index].disabled = false;
aInput[this.index].value = '';
console.log(2);
}
} //[3]函数法，遇到相同的几组元素时，只操作一组元素，并用函数传参来实现所有的效果
var oList = document.getElementById('box-list');
var aIn = oList.getElementsByTagName('li'); function fn(i){
var oInput = aIn[i].getElementsByTagName('input')[0];
var oBtnY = aIn[i].getElementsByTagName('button')[0];
var oBtnX = aIn[i].getElementsByTagName('button')[1];
//确定按钮
oBtnY.onclick = function(){
oInput.disabled = true;
}
//取消按钮
oBtnX.onclick = function(){
oInput.disabled = false;
oInput.value = '';
console.log(3);
}
}
for( var i = 0; i < aIn.length; i++){
fn(i);
}
</script>
</body>
</html>