<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style type="text/css">
div{
width: 200px;
height: 100px;
background-color: #ccc;
position: relative;
float: left;
margin: 10px;
}
div input{
/*text-align: center;*/
background-color: limegreen;
border: 1px solid #FF0000;
margin: 0px auto 0;
position: absolute;
bottom: 10px;
left:50%;
display: none;
}
</style>
</head>
<body>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<script type="text/javascript">
var oBtn = document.getElementById('btn');
var aDiv = document.getElementsByTagName('div');
for(var i=0;i<aDiv.length;i++)
{
aDiv[i].onmouseover = function()
{
aDiv[i].innerHTML = "<input type="button" name="btn" id="btn" value="Select" />";
oBtn.style.display = "block";
};
};
/*aDiv[i].onmouseover = function()
{
oBtn.style.display = "block";
}*/
</script>
</body>
</html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style type="text/css">
div{
width: 200px;
height: 100px;
background-color: #ccc;
position: relative;
float: left;
margin: 10px;
}
div input{
/*text-align: center;*/
background-color: limegreen;
border: 1px solid #FF0000;
margin: 0px auto 0;
position: absolute;
bottom: 10px;
left:50%;
display: none;
}
</style>
</head>
<body>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<script type="text/javascript">
var oBtn = document.getElementById('btn');
var aDiv = document.getElementsByTagName('div');
for(var i=0;i<aDiv.length;i++)
{
aDiv[i].onmouseover = function()
{
aDiv[i].innerHTML = "<input type="button" name="btn" id="btn" value="Select" />";
oBtn.style.display = "block";
};
};
/*aDiv[i].onmouseover = function()
{
oBtn.style.display = "block";
}*/
</script>
</body>
</html>
for(var i=0;i<aDiv.length;i++)
{aDiv[i].onmouseover = function()
{
this.innerHTML = '<input type="button" name="btn" value="Select" />';
var oBtn = this.getElementsByTagName("input")[0];
oBtn.style.display = "block";
};
};
for(let i=0;i<aDiv.length;i++)
{
aDiv[i].onmouseover = function()
{
aDiv[i].innerHTML = "<input type='button' name='btn' id='btn' value='Select' />";
//alert(aDiv[i]);
var oBtn = document.getElementById('btn');
oBtn.style.display = "block";
};
};
这样你看行不行
你这样不行。有两个问题。
一,
事件执行时,for循环早就结束了,这个时候i已经是最大值加1了。
解决方法是可以用闭包把每次循环i的值保存起来。
或者在事件函数内不使用循环变量i,而是用this获取触发事件的元素二,
同一页面中元素的id必须是唯一的,id不能重复,重复的id用document.getElementById()获取时,只能获取到第一个。