jquery+php实现ajax单个上传

HTML部分 <script type="text/javascript" src="jquery.min.js"></script> <script type="text/javascript" src="jquery.form.js"></script>   <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> CSS部分 .btn{position: relative;overflow: hidden;margin-right: 4px;display:inline-block; *display:inline;padding:4px 10px 4px;font-size:14px;line-height:18px; *line-height:20px;color:#fff; text-align:center;vertical-align:middle;cursor:pointer;background:#5bb75b; border:1px solid #cccccc;border-color:#e6e6e6 #e6e6e6 #bfbfbf; border-bottom-color:#b3b3b3;-webkit-border-radius:4px; -moz-border-radius:4px;border-radius:4px;} .btn input{position: absolute;top: 0; right: 0;margin: 0;border:solid transparent; opacity: 0;filter:alpha(opacity=0); cursor: pointer;} .progress{position:relative; margin-left:100px; margin-top:-24px;   width:200px;padding: 1px; border-radius:3px; display:none} .bar {background-color: green; display:block; width:0%; height:20px;   border-radius:3px; } .percent{position:absolute; height:20px; display:inline-block;   top:3px; left:2%; color:#fff } .files{height:22px; line-height:22px; margin:10px 0} .delimg{margin-left:20px; color:#090; cursor:pointer} js部分 $(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 + '%'; //得到进度                 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                 //得到后台返回的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             }         });     });     ... }); //接下来，文件上传完成，若是用户想删除上传的文件，能够写个ajax post请求来完成删除操做。 $(function () {     ...接上面的代码     $(".delimg").live('click',function(){         var pic = $(this).attr("rel");         $.post("action.php?act=delimg",{imagename:pic},function(msg){             if(msg==1){                 files.html("删除成功.");                 showimg.empty(); //清空图片                 progress.hide(); //隐藏进度条             }else{                 alert(msg);             }         });     }); }); PHP部分 action.php中须要处理图片上传以及删除图片。图片上传时须要验证格式和大小，而后经过move_uploaded_file()方法上传图片，最后返回json格式的数据。删除图片时使用unlink()便可完成删除操做。 $action = $_GET['act']; if($action=='delimg'){ //删除图片     $filename = $_POST['imagename'];     if(!empty($filename)){         unlink('files/'.$filename);         echo '1';     }else{         echo '删除失败.';     } }else{ //上传图片     $picname = $_FILES['mypic']['name'];     $picsize = $_FILES['mypic']['size'];     if ($picname != "") {         if ($picsize > 512000) { //限制上传大小             echo '图片大小不能超过500k';             exit;         }         $type = strstr($picname, '.'); //限制上传格式         if ($type != ".gif" && $type != ".jpg") {             echo '图片格式不对！';             exit;         }         $rand = rand(100, 999);         $pics = date("YmdHis") . $rand . $type; //命名图片名称         //上传路径         $pic_path = "files/". $pics;         move_uploaded_file($_FILES['mypic']['tmp_name'], $pic_path);     }     $size = round($picsize/1024,2); //转换成kb     $arr = array(         'name'=>$picname,         'pic'=>$pics,         'size'=>$size     );     echo json_encode($arr); //输出json数据 } 本文借助了jquery form插件来完成单文