jquery.form 和MVC4做无刷新上传DEMO

<script src="~/Scripts/jquery-1.10.2.min.js"></script>
<script type="text/javascript" src="/Scripts/jquery.form.js"></script>
<script type="text/javascript" src="/Scripts/common.js"></script>  

<form accept-charset="UTF-8" id="node_form" method="post" action="">
    <input size="30" class="tino_file" maxlength="128" name="pic" id="field-pic" imgstyle=" width=100" type="text" />
    <input size="30" class="tino_file1" maxlength="128" name="pic1" id="field-pic1" imgstyle=" width=100" type="text" />        
</form>

$(document).ready(function(){
    $(‘input.tino_file‘).each(function(){
        var form=$(this).parents("form");
        form.attr(‘enctype‘,‘multipart/form-data‘);
        var old_name=$(this).attr(‘name‘);
        $(this).hide();
        var new_name=old_name+‘_file‘;
        var imgstyle=$(this).attr(‘imgstyle‘);
        var imgstr=‘‘;
        var old_file=$(this).val();

        if(‘‘!=old_file)
        {
            imgstr=‘<a href="‘+old_file+‘" target="_blank"><img src="‘+old_file+‘" ‘+imgstyle+‘></a> <a href="###" onclick="del_pic(\‘‘+old_name+‘\‘)">删除</a>‘;
        }
        var str=‘<input type="file" name="‘+new_name+‘" id="‘+new_name+‘" value=""><input type="hidden" id="‘+new_name+‘_del" value=""><div id="‘+new_name+‘_show">‘+imgstr+‘</div>‘;
        $(this).after(str);

        var ahah=$(this);
    
        $(‘#‘+new_name).change(function(){
            var tmp=$(this).val();
            if(‘‘!=tmp)
            {
                //alert(ahah.val());
                form.ajaxSubmit({
                    url:"/Home/UploadImage",
                    type: ‘POST‘,
                    data:{‘field‘:new_name,‘only_img‘:‘yes‘,‘old_img‘:$(‘#‘+new_name+‘_del‘).val()},
                    dataType: "json",
                    //beforeSend:function(){loading_start();},
                    success: function(result) {
                        if (‘‘ != result.url) {
                            var tmp = result;
                        
                            $(‘#‘ + new_name + ‘_show‘).html(‘<a href="‘ + tmp.url + ‘" target="_blank"><img src="‘ + tmp.realpath + ‘" ‘ + imgstyle + ‘></a> <a href="###" onclick="del_pic(\‘‘ + old_name + ‘\‘)">删除</a>‘);
                            ahah.val(tmp.url);
                            $(‘#‘ + new_name + ‘_del‘).val(tmp.realpath);
                        
                            window.onbeforeunload = function () {

                            }
                        } else {
                            alert("请选择正确图片上传");
                        }
                        
                        
                    }
                });
            }
        });
        

    });

        public JsonResult UploadImage()
        {
            var relativeurl = "";//相对路径
            var realurlpath = "";//绝对路径
            if (Request.Files.Count <= 0)
                return Json(new
                {
                    url =relativeurl,
                    realpath=realurlpath
                });
            for(var i = 0;i < Request.Files.Count;i++)
            {
                var extensionname = DateTime.Now.ToString("yyyyMMddmmss");
                var file = HttpContext.Request.Files[i];
                if (file == null || file.ContentLength <= 0) continue;
                var originExtensionName = EnHtml(HttpUtility.UrlDecode(file.FileName,Encoding.GetEncoding("GB2312"))).Substring(EnHtml(HttpUtility.UrlDecode(file.FileName,Encoding.GetEncoding("GB2312"))).Length - 3);
                if (originExtensionName.ToLower() != "jpg" && originExtensionName.ToLower() != "gif") continue;
                var newFile = extensionname + "." + originExtensionName;
                relativeurl = newFile;
                realurlpath = "/upfile/" + newFile;
                file.SaveAs(HttpContext.Server.MapPath("/upfile/" + newFile));
            }
            return Json(new {
                url = relativeurl,
                realpath = realurlpath
            });
        }

        private static string EnHtml(string str) {
            if(str == null)
                return "";
            str = str.Replace(" ","");

            str = str.Trim();
            return str;
        }