HarmonyOS 鸿蒙Next 元服务不支持imagePackerApi.packToFile()方法

使用元服务支持的api实现packToFile()，示例代码如下：

  packToFile() {

    const imagePackerApi: image.ImagePacker = image.createImagePacker();

    const context: Context = getContext(this);

    const path: string = context.filesDir + "/test.jpg";

    const imageSourceApi: image.ImageSource = image.createImageSource(path);

    imageSourceApi.createPixelMap().then((pixelMap: image.PixelMap) => {

      console.info('Succeeded in creating pixelMap object through image decoding parameters.');

      // 图片压缩或重新打包

      let packOpts: image.PackingOption = { format: "image/jpeg", quality: 98 }

      imagePackerApi.packing(pixelMap, packOpts).then((data: ArrayBuffer) => {

        console.info('Succeeded in packing the image.');

        this.createFile(data)

      }).catch((error: BusinessError) => {

        console.error(`Failed to pack the image.code ${error.code},message is ${error.message}`);

      })

    }).catch((error: BusinessError) => {

      console.error('Failed to create pixelMap object through image decoding parameters.');

    })

  }

  // ArrayBuffer 写入 file

  createFile(data: ArrayBuffer): void {

    let context = getContext(this) as common.UIAbilityContext;

    let filesDir = context.filesDir;

    let file = fs.openSync(filesDir + '/test.jpg', fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);

    let writeLen = fs.writeSync(file.fd, data);

    console.info("The length of str is: " + writeLen);

    fs.closeSync(file);

  }