将来自Xam.Plugin.Media 5.0.1的图像源转换为Xamarinforms中的字节数组?

Question

if (!CrossMedia.Current.IsPickPhotoSupported)
{
await Application.Current.MainPage.DisplayAlert("Photos Not Supported", ":( Permission not granted to photos.", "OK");
return;
}
var file = await Plugin.Media.CrossMedia.Current.PickPhotoAsync(new Plugin.Media.Abstractions.PickMediaOptions
{
PhotoSize = Plugin.Media.Abstractions.PhotoSize.Medium,
});

if (file == null)
return;
var tmpSrc = ImageSource.FromStream(() =>
{
var stream = file.GetStream();
file.Dispose();
return stream;
});

ImageSource toBeConversion = tmpSrc;

• 我希望变量toBeConvert转换为 Byte[] 所以 我可以将其发送到我的网络 ...

Answer 1

ImageSource

是一种为 Xamarin.Forms.Image 提供源图像以显示某些内容的方法。如果您已经在屏幕上显示某些内容，则Image视图中填充了来自其他位置的数据，例如文件或资源或存储在内存中的数组中......或者不管你一开始就得到了它。与其尝试从ImageSource中获取该数据，不如保留对它的引用并根据需要上传。

因此，您可以在选择照片后从文件中获取字节数组。

var file = await Plugin.Media.CrossMedia.Current.PickPhotoAsync(new Plugin.Media.Abstractions.PickMediaOptions
{
PhotoSize = Plugin.Media.Abstractions.PhotoSize.Medium,
});
if (file == null)
return;    
var bytes = File.ReadAllBytes(file.Path); // you could get  the byte[] here from the file path.

Answer 2

• 这段代码也对我有用...

  private async void Capture()
  {
  if (!CrossMedia.Current.IsCameraAvailable || !CrossMedia.Current.IsTakePhotoSupported)
  {
  await Application.Current.MainPage.DisplayAlert("No Camera", ":( No camera available.", "OK");
  return;
  }
  var file = await CrossMedia.Current.TakePhotoAsync(new Plugin.Media.Abstractions.StoreCameraMediaOptions
  {
  Directory = "Test",
  SaveToAlbum = true,
  CompressionQuality = 75,
  CustomPhotoSize = 50,
  PhotoSize = PhotoSize.Medium,
  DefaultCamera = CameraDevice.Front
  });
  if (file == null)
  return;
  var stream = file.GetStream();
  if (stream != null)
  {
  var StreamByte = ReadAllBytes(stream);
  var NewStream = new MemoryStream(StreamByte);
  // stream = mystream;
  Device.BeginInvokeOnMainThread(() => {
  ImageSource = ImageSource.FromStream(() => NewStream);
  });
  student.ProfilePicture = StreamByte;
  }
  }
  public byte[] ReadAllBytes(Stream instream)
  {
  if (instream is MemoryStream)
  return ((MemoryStream)instream).ToArray();
  using (var memoryStream = new MemoryStream())
  {
  instream.CopyTo(memoryStream);
  return memoryStream.ToArray();
  }
  }