圖像到字節[]，Convert和ConvertBack

Question

我有一項將網站上存儲的圖像轉換為字節數組的服務

                HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create("URLTOIMAGE");
                myRequest.Method = "GET";
                HttpWebResponse myResponse = (HttpWebResponse)myRequest.GetResponse();
                Bitmap bmp = new Bitmap(myResponse.GetResponseStream());
                myResponse.Close();
                ms = new MemoryStream();
                bmp.Save(ms, ImageFormat.Bmp);

此代碼返回一個字節數組，該字節數組存儲在數據庫（SQL Azure）中。 在Windows Phone應用程序中，我嘗試轉換此字節數組以在頁面上顯示它。

public class BytesToImageConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        BitmapImage empImage = new BitmapImage();
        empImage.SetSource(new MemoryStream((Byte[])value));
        return empImage;
    }

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

字節數組被應用程序很好地接收，但是當我嘗試執行SetSource時會引發異常。

empImage.SetSource(new MemoryStream((Byte[])value));
=> "Exception was unhandled", The request is not supported

你能幫助我嗎？ 謝謝

Answer 1

此代碼有效：

public class BytesToImageConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        MemoryStream stream = new MemoryStream((Byte[])value);
        WriteableBitmap bmp = new WriteableBitmap(173, 173);
        bmp.LoadJpeg(stream);
        return bmp;
    }

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

謝謝大家 ：）

Answer 2

這些問題已經在stackoverflow上得到了解答
為圖像到一個字節[]試試這個
並為字節[]圖像試試這個

Answer 3

private ImageSource GetPhoto(byte[] bytearr)
{
   if (bytearr != null)
   {
      BitmapImage image = new BitmapImage();

      InMemoryRandomAccessStream ms = new InMemoryRandomAccessStream();
      ms.AsStreamForWrite().Write(bytearr, 0, bytearr.Length);
      ms.Seek(0);

      image.SetSource(ms);
      ImageSource src = image;

      return src;
   }
   else
      return null;
}

Answer 4

對於我的UWP應用，我使用以下IValueConverter將字節數組轉換為<Image Source={Binding} />的可綁定對象。

internal class ByteImageSourceConverter : IValueConverter
{
    object IValueConverter.Convert(object value, Type targetType, object parameter, string language)
    {
        if (value == null)
            return null;
        return ByteToImage((byte[])value);
    }

    object IValueConverter.ConvertBack(object value, Type targetType, object parameter, string language)
    {
        throw new NotImplementedException();
    }

    static ImageSource ByteToImage(byte[] imageBytes)
    {
        BitmapImage image = new BitmapImage();
        image.SetSource(imageBytes.ConvertToInMemoryRandomAcessStream());
        ImageSource src = image;
        return src;
    }
}

internal static InMemoryRandomAccessStream ConvertToInMemoryRandomAcessStream(this byte[] arr)
{
    var randomAccessStream = new InMemoryRandomAccessStream();
    randomAccessStream.WriteAsync(arr.AsBuffer());
    randomAccessStream.Seek(0);
    return randomAccessStream;
}

對不起，我使用同步功能中的WriteAsync。 為了這篇文章的目的，我沒有時間解決這個問題，但是它是這樣工作的:)