<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>3種用tagname和id獲取元素的方法</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">分類名稱</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]整體法，先獲取所有的元素，再通過ai+-b的方法來算出需要的元素
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++){
//確定按鈕
aBtn[2*i].onclick = function(){
aInput[this.index/2].disabled = true;
}
//取消按鈕
aBtn[2*i+1].onclick = function(){
aInput[(this.index-1)/2].disabled = false;
aInput[(this.index-1)/2].value = '';
console.log(1);
}
}
//[2]數組法，在全局環境下建立空數組，遇到需要循環的結構時，在循環中獲取元素，並放入數組
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;
//確定按鈕
aBtnY[i].onclick = function(){
aInput[this.index].disabled = true;
}
//取消按鈕
aBtnX[i].onclick = function(){
aInput[this.index].disabled = false;
aInput[this.index].value = '';
console.log(2);
}
}
//[3]函數法，遇到相同的幾組元素時，只操作一組元素，並用函數傳參來實現所有的效果
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];
//確定按鈕
oBtnY.onclick = function(){
oInput.disabled = true;
}
//取消按鈕
oBtnX.onclick = function(){
oInput.disabled = false;
oInput.value = '';
console.log(3);
}
}
for( var i = 0; i < aIn.length; i++){
fn(i);
}
</script>
</body>
</html>
