jQuery之图片预览
主要知识点：
1）on() 事件绑定
2）DOM操作的实战运用
代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>在线相册</title>
<style>
ul{
list-style: none;
overflow: hidden;
}
ul li{
display: block;
float: left;
margin-left: 5px;
}
ul li img{
display: block;
}
</style>
</head>
<body>
<h2>在线预览</h2>
<p>
<label for="img_url">上传图片:
<input type="file" name="img_url" id="img_url" placeholder="上传图片">
</label>
</p>
<p>
图片类型:
<input type="radio" id="rect" name="border" value="0"><label for="rect">直角</label>
<input type="radio" id="radius" name="border" value="10%"><label for="radius">圆角</label>
<input type="radio" id="circle" name="border" value="50%"><label for="circle">圆形</label>
</p>
<p>
是否添加阴影:
<select name="shadow">
<option value="0">不添加</option>
<option value="1">添加</option>
</select>
</p>
<p>
<button class="btn">添加图片</button>
</p>
<div>
<h3>预览</h3>
<ul></ul>
</div>
</body>
<script src="./js/jquery.min.js"></script>
<script>
$(function(){
$(".btn").on("click",function(){
// 获取图片路径
let imgUrl = $('#img_url').val();
if(imgUrl.length === 0){
alert("请选择一张图片");
$('#img_url').focus();
return false;
}
console.log('http://theyon.com/0918/images/'+imgUrl.split('\\')[2]);
imgUrl = 'http://theyon.com/0918/images/'+imgUrl.split('\\')[2];
// 获取图片显示类型
let imgType = $("input[type=radio]:checked").val();
console.log(imgType);
// 获取图片显示效果
let shadow = 'none';
if($(':selected').val() === '1'){
shadow = '3px 3px 3px #666';
}
// 创建图片
let img = $('<img>')
.attr('src',imgUrl)
.width(150)
.height(150)
.css({
'border-radius': imgType,
'box-shadow': shadow
});
// 图片操作
let before = $('<button></button>').text('前移');
let after = $('<button></button>').text('后移');
let remove = $('<button></button>').text('删除');
// 创建一个<li>用来放所有的内容
let contaier = $('<li>');
//将图片和三个按钮打包到<li>中
contaier.append(img,before,after,remove);
$('ul').append(contaier);
before.click(function(){
let current = $(this).parent();
let prev = current.prev();
prev.before(current);
});
after.click(function(){
let current = $(this).parent();
let next = current.next();
next.after(current);
})
remove.click(function(){
let current = $(this).parent();
if(confirm('确认删除吗?')){
current.remove();
}
return false;
})
})
})
</script>
</html>运行结果
