<!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>
