public MessageObjectPO<UploadPO> OnPostUpload(UploadRO uploadRO) {

            var response = new MessageObjectPO<UploadPO>();

            Guid guid = Guid.NewGuid();

            string FilePath = _serverSettings.SafetyRuleTempPath + "\\" + guid + "\\";

            DirectoryInfo di = new DirectoryInfo(FilePath);

            if (!di.Exists) {

                di.Create();

            }

            using (var stream = System.IO.File.Create(FilePath + "\\" + uploadRO.fileName)) {

                byte[] bytes = uploadRO.content;

                stream.Write(bytes, 0, uploadRO.content.Length);

                response.Data = new UploadPO() {

                    Edition = DateTime.Now.DayOfYear,

                    Revision = 0,

                    MinorVersion = 0,

                    OperativeFrom = DateTime.Now,

                    VersionFileSharePointPath = FilePath.Replace(@"\\", @"\"),

                    VersionFileName = uploadRO.fileName,

                    VersionFileSize = uploadRO.fileSize / 1024 / 1024,

                    VersionId = Guid.NewGuid(),

                };

            }

            response.StatusCode = HttpStatusCode.OK;

            return response;

        }

 public class UploadRO {

        public string uid { get; set; }

        public string fileName { get; set; }

        public int fileSize { get; set; }

        public byte[] content { get; set; }

    }

function onSaveRequest(

        files: UploadFileInfo[],

        options: { formData: FormData; requestOptions: any },

        onProgress: (uid: string, event: ProgressEvent<EventTarget>) => void

    ): Promise<{ uid: string }> {

        const currentFile = files[0] as UploadFileInfo;

        const uid = currentFile.uid;

        const saveRequestPromise = new Promise<{ uid: string }>( (resolve, reject) => {

            // as currently configured it is impossible to request a save from the UI if there are validation errors, but that can be changed so keeping this check in place

            if (currentFile.validationErrors && currentFile.validationErrors.length > 0) {

                reject({ uid: uid });

            } else {

                const reader = new FileReader();

                // onload is executed when the load even is fired i.e. when content read with readAsArrayBuffer, readAsBinaryString, readAsDataURL or readAsText is available

                reader.onload = () => {

                    if (reader.result && typeof reader.result === "string") {

                        // stripping the data-url declaration as per https://developer.mozilla.org/en-US/docs/Web/API/FileReader/readAsDataURL

                        const base64Result = reader.result.split(",")[1];

                        // update viewModel and resolve

                        const fileUpload: IFileUploadViewModel = { uid: uid, fileName: currentFile.name, fileSize: currentFile.size!, content: base64Result};

                        Handler_Upload(fileUpload);

                        resolve({ uid: uid });

                    } else {

                        reject({ uid: uid });

                    }

                };

                // onprogress is fired periodically as the FileReader reads data and the ProgressEvent can be passed directly to the Upload control, handy!

                reader.onprogress = (data) => {

                    reader.readAsArrayBuffer(currentFile.getRawFile!())

                    console.log(data)

                    onProgress(uid, data);

                };

                // if the read is not completed due to error or user intervention, reject

                reader.onabort = () => {

                    reject({ uid: uid });

                };

                reader.onerror = () => {

                    reject({ uid: uid });

                };

               reader.readAsDataURL(currentFile.getRawFile!());

            }

        });

        return saveRequestPromise;

    }

const pageTable = (

        <div>

            <Upload

                {...fileProps}

                batch={false}

                multiple={false}

                defaultFiles={[]}

                showFileList={true}

                restrictions={{

                    allowedExtensions: [".pdf"],

                }}

                withCredentials={true}

                onAdd={onAdd}

                onProgress={onProgress}

                onStatusChange={onStatusChange}

                onBeforeUpload={onBeforeUpload}

                onRemove={onRemove}

                saveUrl={onSaveRequest}

            />

        </div>

    )

    return <>{pageTable}</>

  beforeUpload(file, fileList) {

   var reader = new FileReader();

   const image = new Image();

   var height;

   var width;

   var base64Url;

   //因为读取文件需要时间,所以要在回调函数中使用读取的结果

   reader.readAsDataURL(file); //开始读取文件

   reader.onload = (e) => {

     image.src = reader.result;

     image.onload = () => {

       height = image.naturalHeight;

       width = image.naturalWidth;

       base64Url= e.target.result, //cropper的图片路径

     }

   }

   return false;

 }