必须组件
jquery.min.js和jquery.form.js
<div class="demo">
<p>说明:示例中只允许上传gif/jpg格式的图片,图片大小不能超过500k。</p>
<div class="btn">
<span>添加附件</span>
<input id="fileupload" type="file" name="mypic">
</div>
<div class="progress">
<span class="bar"></span><span class="percent">0%</span >
</div>
<div class="files"></div>
<div id="showimg"></div>
</div>
$(function () {
var bar = $('.bar');
var percent = $('.percent');
var showimg = $('#showimg');
var progress = $(".progress");
var files = $(".files");
var btn = $(".btn span");
$("#fileupload").wrap("<form id='myupload' action='action.php'
method='post' enctype='multipart/form-data'></form>");
$("#fileupload").change(function(){ //选择文件
$("#myupload").ajaxSubmit({
dataType: 'json', //数据格式为json
beforeSend: function() { //开始上传
showimg.empty(); //清空显示的图片
progress.show(); //显示进度条
var percentVal = '0%'; //开始进度为0%
bar.width(percentVal); //进度条的宽度
percent.html(percentVal); //显示进度为0%
btn.html("上传中..."); //上传按钮显示上传中
},
uploadProgress: function(event, position, total, percentComplete) {
var percentVal = percentComplete + '%'; //获得进度
bar.width(percentVal); //上传进度条宽度变宽
percent.html(percentVal); //显示上传进度百分比
},
success: function(data) { //成功
//获得后台返回的json数据,显示文件名,大小,以及删除按钮
files.html("<b>"+data.name+"("+data.size+"k)</b>
<span class='delimg' rel='"+data.pic+"'>删除</span>");
//显示上传后的图片
var img = "http://demo.helloweba.com/upload/files/"+data.pic;
showimg.html("<img src='"+img+"'>");
btn.html("添加附件"); //上传按钮还原
},
error:function(xhr){ //上传失败
btn.html("上传失败");
bar.width('0');
files.html(xhr.responseText); //返回失败信息
}
});
});
...
});
http://www.1983blue.com/posts/php-jquery-form-js