Question

我需要像字节数组一样传递图像（Image _thresholdedImage）...我不知道怎么做到这一点。任何的想法？谢谢！

_thresholdedImage.Source = ImageSource.FromStream (() => photo.Source);

var tessResult = await _tesseractApi.SetImage(imageBytes);

Answer 1

我无法在X.Forms中转换它，而是使用以下代码和依赖服务。谢谢大家。

    public async Task<byte[]> GetBytesFromImage(string filePath)
    {
        ConvertImageToBW(filePath);

        // Create another bitmap that will hold the results of the filter.
        Bitmap thresholdedBitmap = Bitmap.CreateBitmap (BitmapFactory.DecodeFile(filePath));

        thresholdedBitmap = BitmapFactory.DecodeFile (thresholdedImagePath);

        byte[] bitmapData;
        using (var stream = new MemoryStream())
        {
            thresholdedBitmap.Compress(Bitmap.CompressFormat.Png, 0, stream);
            bitmapData = stream.ToArray();
        }

        return bitmapData;
    }

Answer 2

您是否尝试过使用转换器？

 public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        ImageSource retSource = null;
        if (value != null)
        {
            byte[] imageAsBytes = (byte[])value;
            retSource = ImageSource.FromStream(() => new MemoryStream(imageAsBytes));
        }
        return retSource;
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }

Answer 3

您可以使用以下功能：

  public async Task<byte[]> Download(string url)
        {
            using (HttpClient client = new HttpClient())
            {
                byte[] fileArray = await client.GetByteArrayAsync(url);
                return fileArray;
            }

        }

Answer 4

通过在xamairn表单中使用Java.Io，我们可以从imagePath获取字节数组。它适用于所有平台。

private static byte[] GetBytesFromImage(string imagePath)
        {
            var imgFile = new File(imagePath);
            var stream = new FileInputStream(imgFile);
            var bytes = new byte[imgFile.Length()];
            stream.Read(bytes);
            return bytes;
        }

Answer 5

以下代码可用于将图像转换为字节数组。这里使用 CrossMedia 插件从相机中捕获图像。

public byte[] imageByte;
Stream imageStream = null; 
var file = await CrossMedia.Current.TakePhotoAsync(new Plugin.Media.Abstractions.StoreCameraMediaOptions
       { Name = "pic.jpg"});
if (file == null) return;
imageStream = file.GetStream();
BinaryReader br = new BinaryReader(imageStream);
imageByte = br.ReadBytes((int)imageStream.Length);

Answer 6

事实证明，您可以将MediaFile对象转换为字节数组。因此，无需将文件转换为ImageSource或Image。

var photo = await CrossMedia.Current.TakePhotoAsync(new Plugin.Media.Abstractions.StoreCameraMediaOptions() { });

byte[] imageArray = null;

using (MemoryStream memory = new MemoryStream()) {

    Stream stream = photo.GetStream();
    stream.CopyTo(memory);
    imageArray = memory.ToArray();
}

来源：https://forums.xamarin.com/discussion/156236/how-to-get-the-bytes-from-the-imagesource-in-xamarin-forms
在Xamarin论坛中向用户“ ajaxer”大喊大叫，该用户的解决方案在此问题上花了3天后才救了我。 ?

在Xamarin.Forms中将Image转换为字节数组

6 个答案: