ajax无刷新上传

我们在使用上传控件的时候，会遇到刷新的问题，最近使用ajax做的上传，觉得效果还是很不错。

首先，我们需要在页面上放上上传控件；需要注意的是，我们必须放在form里面，实现表单上传。

 <form class="picForm" name="uploadPic" enctype="multipart/form-data">
        选择图片：<input type="file" class="file" name="picture" /><br />
 </form>

 前台提交方法

function TajaxFileUpload() {
               var mypath = "../ajax/upload.ashx?fileName="+需要的参数;
                $("form[name='uploadPic']").ajaxSubmit({
                    url: mypath,
                    type: 'POST',
                    success: function (html, status) {
                        if (status == "success") {
                            html = html.replace(/</?[^>]*>/g, '');
                            //html = html.replace(/[ | ]*
/g, '
');
                            var json = eval('(' + html + ')');
                            if (json.state == "success") {
                              //上传成功
                                      } 
                            else {//上传失败
                                      }
                               } 
                             else {
                            art.dialog.alert("请求数据失败");
                                  } //stauts success
                    } //submit success
                }); //ajaxSubmit
            
        } //t ajax

 upload.ashx代码如下

using System;
using System.IO;
using System.Web;
using System.Text;
using System.Net;

namespace BatchImageUpload
{
    /// <summary>
    /// Summary description for upload
    /// </summary>
    public class upload : IHttpHandler
    {

        public void ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "text/plain";
            try
            {
                if (context.Request.Files["picture"] == null)
                {
                    //图片控件中没有选择图片
                    context.Response.Write("{state:'error',msg:'您还未选择图片'}");
                }
                else
                {

                    string fileName = context.Request.QueryString["fileName"];
                    HttpPostedFile pic = context.Request.Files["picture"];
                    string foldPath = HttpContext.Current.Server.MapPath("/") + @"OrderUserInfoImages";
                    foldPath = foldPath + fileName;
                    DirectoryInfo di = new DirectoryInfo(foldPath);
                    if (!di.Exists)//如果文件夹目录不存在
                    {
                        di.Create();//新建文件夹
                    }
                    string imageName = UpLoadImage(pic, foldPath);
                    context.Response.Write("{state:'success',msg:'上传成功：" + imageName + "'}");




                }
            }
            catch (Exception ex)
            {
                context.Response.Write("{state:'error',msg:'" + ex.Message + "'}");
            }
        }

        #region 上传图片
        /// <summary>
        /// 上传图片
        /// </summary>
        /// <param name="imgfile">文件http流</param>
        /// <param name="nowpath">所需放置的文件路径</param>
        /// <returns>上传成功，返回字符串，否则，抛出异常</returns>
        public static string UpLoadImage(HttpPostedFile imgfile, string nowpath)
        {
            try
            {
                string serverPath = System.Web.HttpContext.Current.Server.MapPath("~");

                string toFilePath = Path.Combine(serverPath, nowpath);

                //获取要保存的文件信息
                FileInfo file = new FileInfo(imgfile.FileName);
                //获得文件扩展名
                string fileNameExt = file.Extension;

                //验证合法的文件
                if (CheckImageExt(fileNameExt))
                {
                    //生成将要保存的随机文件名
                    string fileName = GetImageName() + fileNameExt;

                    //获得要保存的文件路径
                    string serverFileName = toFilePath + fileName;
                    //物理完整路径                    
                    string toFileFullPath = serverFileName; //HttpContext.Current.Server.MapPath(toFilePath);

                    //将要保存的完整文件名                
                    string toFile = toFileFullPath;//+ fileName;

                    ///创建WebClient实例       
                    WebClient myWebClient = new WebClient();
                    //设定windows网络安全认证   方法1
                    myWebClient.Credentials = CredentialCache.DefaultCredentials;
                    ////设定windows网络安全认证   方法2
                    imgfile.SaveAs(toFile);
 
                    string relativePath =fileName;
                    return relativePath;
                }
                else
                {
                    throw new Exception("文件格式非法，请上传gif|jpg|bmp|png格式的文件。");
                }
            }
            catch
            {
                throw;
            }
        }
        #endregion

        #region 图片上传格式和文件名
        /// <summary>
        /// 检查是否为合法的上传图片
        /// </summary>
        /// <param name="_fileExt"></param>
        /// <returns></returns>
        public static bool CheckImageExt(string _ImageExt)
        {
            string[] allowExt = new string[] { ".gif", ".jpg", ".jpeg", ".bmp", ".png" };
            for (int i = 0; i < allowExt.Length; i++)
            {
                if (string.Compare(allowExt[i], _ImageExt, true) == 0)
                { return true; }
            }
            return false;

        }

        private static string GetImageName()
        {
            Random rd = new Random();
            StringBuilder serial = new StringBuilder();
            serial.Append(DateTime.Now.ToString("yyyyMMddHHmmssff"));
            serial.Append(rd.Next(0, 999999).ToString());
            return serial.ToString();

        }

        #endregion

        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }
}

 单文件上传只需要按照这个方法就可以。如果要做到批量上传，需要动态添加上传控件，然后遍历上传控件坐上传功能即可