Web Api 接收图片

 public async Task<HttpResponseMessage> Upload()
        {
            if (!Request.Content.IsMimeMultipartContent())
            {
                throw new HttpResponseException(HttpStatusCode.UnsupportedMediaType);
            }

            string fileSaveLocation = HttpContext.Current.Server.MapPath("/img");
            CustomMultipartFormDataStreamProvider provider = new CustomMultipartFormDataStreamProvider(fileSaveLocation);

            List<string> files = new List<string>();
            try
            {
                await Request.Content.ReadAsMultipartAsync(provider);
                ].LocalFileName;
                FileAttributes attr = File.GetAttributes(path);
                if (attr == FileAttributes.Directory)
                {
                    Directory.Delete(path, true);
                }
                else
                {
                    File.Delete(path);
                }

                foreach (var file in provider.FileData)
                {
                    files.Add(file.LocalFileName);
                }
                return new HttpResponseMessage(HttpStatusCode.OK)
                {
                    Content = ])
                };
            }
            catch (Exception ex)
            {
                return Request.CreateErrorResponse(HttpStatusCode.InternalServerError, ex);
            }
        }

 public class CustomMultipartFormDataStreamProvider : MultipartFormDataStreamProvider
    {
        public CustomMultipartFormDataStreamProvider(string path) : base(path)
        {

        }

        public override string GetLocalFileName(HttpContentHeaders headers)
        {
            return headers.ContentDisposition.FileName.Replace("\"", string.Empty);
        }
    }

 function upload() {
            var url = "http://localhost:42561/api/upload";
            var formData = new FormData($("#uploadForm")[0]);
            $.ajax({
                url: url,
                type: "post",
                data: formData,
                async: false,//设置所有请求为同步请求
                cache: false,//false 表示第一次请求完毕之后，如果再次去请求，直接从缓存里面读取而不是再到服务器端读取。该值默认为true
                contentType: false,
                processData: false,//false 表示提交的时候不会序列化 data,而是直接使用 data,默认为 true
                success: function (result) {
                    $("img").attr("src", result);
                    console.log($("img").length);
                },
                error: function (result) {
                    console.log(result);
                }
            });
            return false;
        }

    <div>
        <form id="uploadForm">
            <input type="file" name="file" value="" /><br />
        </form>
        <input type="button" value="上传" onclick="upload();" />
    </div>
    <hr />
    <div>
        <img src="" />
    </div>