问如何在离子3中从画廊中获取或选择图像

EN

 //take Photo
  takePhoto(sourceType:number) {
    const options: CameraOptions = {
      quality: 50,
      destinationType: this.camera.DestinationType.DATA_URL,
      encodingType: this.camera.EncodingType.JPEG,
      mediaType: this.camera.MediaType.PICTURE,
      correctOrientation: true,
      sourceType:sourceType,
    }

    this.camera.getPicture(options).then((imageData) => {
      let base64Image = 'data:image/jpeg;base64,' + imageData;
    }, (err) => {
      // Handle error
    });
  }

  private optionsCamera: CameraOptions = {
    quality: 100,
    targetWidth: 600,
    sourceType: this.camera.PictureSourceType.CAMERA,
    destinationType: this.camera.DestinationType.DATA_URL,
    encodingType: this.camera.EncodingType.JPEG,
    mediaType: this.camera.MediaType.PICTURE
  }

  private optionsGallery: CameraOptions = {
    quality: 100,
    sourceType: this.camera.PictureSourceType.PHOTOLIBRARY,
    destinationType: this.camera.DestinationType.DATA_URL,
    encodingType: this.camera.EncodingType.JPEG,
    mediaType: this.camera.MediaType.PICTURE
  }

this.camera.getPicture(this.optionsCamera).then((imageData) => {
  let base64Image = 'data:image/jpeg;base64,' + imageData;
 }, (err) => {
  // Handle error
  console.log(err)
 })

this.camera.getPicture(this.optionsGallery).then((imageData) => {
  let base64Image = 'data:image/jpeg;base64,' + imageData;
 }, (err) => {
  // Handle error
  console.log(err)
 })

TakeCamera() {
    const options: CameraOptions = {
      quality: 100,
      destinationType: this.camera.DestinationType.DATA_URL,
      encodingType: this.camera.EncodingType.JPEG,
      mediaType: this.camera.MediaType.PICTURE
    }
    this.camera.getPicture(options).then((imageData) => {
      this.base64Image = 'data:image/jpeg;base64,' + imageData;
      this.photos.push(this.base64Image);
      this.photos.reverse();
    }, (err) => {
      console.log(err);
    });
  }