C#(WinForm)上传图片到服务器

//本地上传代码Files item = fis as Files;
WebClient wc = new WebClient();
string url = stringFormat("{0}Overwrite=true&Path={1}", "服务器上传地址", itemPath);
 wcUploadFile(url, "POST", itemPath);
 //服务器接收
 string ServerSrc = contextServerMapPath("~/DownLogin/");
        foreach (string filekey in contextRequestFiles)
        {
            HttpPostedFile file = contextRequestFiles[filekey];
            string FilePath = PathCombine(ServerSrc, fileFileName);
            if (FileExists(FilePath))
            {
                if (ConvertToBoolean(contextRequest["overwrite"]))
                {
                    FileDelete(FilePath);
                }
                else
                    continue;
            }
            fileSaveAs(FilePath);
        }