ASP.net WebAPI 上传图片实例

[HttpPost]
public Task<Hashtable> ImgUpload()

{

    // 检查是否是 multipart/form-data

    if (!Request.Content.IsMimeMultipartContent("form-data"))

        throw new HttpResponseException(HttpStatusCode.UnsupportedMediaType);

    //文件保存目录路径

    string SaveTempPath = "~/SayPlaces/" + "/SayPic/SayPicTemp/";

    String dirTempPath = HttpContext.Current.Server.MapPath(SaveTempPath);

    // 设置上传目录

    var provider = new MultipartFormDataStreamProvider(dirTempPath);

    //var queryp = Request.GetQueryNameValuePairs();//获得查询字符串的键值集合

    var task = Request.Content.ReadAsMultipartAsync(provider).

        ContinueWith<Hashtable>(o =>

        {

            Hashtable hash = new Hashtable();

            hash["error"] = 1;

            hash["errmsg"] = "上传出错";

            var file = provider.FileData[0];//provider.FormData

            string orfilename = file.Headers.ContentDisposition.FileName.TrimStart('"').TrimEnd('"');

            FileInfo fileinfo = new FileInfo(file.LocalFileName);                    

            //最大文件大小

            int maxSize = 10000000;

            if (fileinfo.Length <= 0)

            {

                hash["error"] = 1;

                hash["errmsg"] = "请选择上传文件。";

            }

            else if (fileinfo.Length > maxSize)

            {

                hash["error"] = 1;

                hash["errmsg"] = "上传文件大小超过限制。";

            }

            else

            {

                string fileExt = orfilename.Substring(orfilename.LastIndexOf('.'));

                //定义允许上传的文件扩展名

                String fileTypes = "gif,jpg,jpeg,png,bmp";

                if (String.IsNullOrEmpty(fileExt) || Array.IndexOf(fileTypes.Split(','), fileExt.Substring(1).ToLower()) == -1)

                {

                    hash["error"] = 1;

                    hash["errmsg"] = "上传文件扩展名是不允许的扩展名。";

                }

                else

                {

                    String ymd = DateTime.Now.ToString("yyyyMMdd", System.Globalization.DateTimeFormatInfo.InvariantInfo);

                    String newFileName = DateTime.Now.ToString("yyyyMMddHHmmss_ffff", System.Globalization.DateTimeFormatInfo.InvariantInfo);

                    fileinfo.CopyTo(Path.Combine(dirTempPath, newFileName + fileExt), true);

                    fileinfo.Delete();

                    hash["error"] = 0;

                    hash["errmsg"] = "上传成功";

                }

            }

            return hash;

        });

    return task;

}