BitmapEncoder FlushAsync()在Xamarin UWP中永远不会返回

Question

我正在使用此代码将png转换为Jpeg，但它卡住了encoder.FlushAsync()并且永远不会返回。我已经尝试了几种方法来解决这个问题，但没有任何效果。encoder.FlushAsync()甚至不给出异常。没有await，调试通过，但图像不正确，使用await，应用程序冻结。我已经提到了下面的链接和代码:

https://www.syncfusion.com/kb/7918/how-to-convert-jpeg-image-from-png-image-and-draw-those-jpeg-image-into-pdf-document

public async Task<Stream> ConvertPngToJpeg2(Stream s)
{
         byte[] resultArray = null;
            
         //Convert stream into byte array
         byte[] image = new byte[s.Length];
         s.Read(image, 0, image.Length);
           
         //Create An Instance of WriteableBitmap object  
         WriteableBitmap resultBitmap = new WriteableBitmap(1, 1);
 
         using (IRandomAccessStream ms = new InMemoryRandomAccessStream())
          {
              await ms.WriteAsync(image.AsBuffer());
              ms.Seek(0);
                
               //Set the source for WriteableBitmap  
               resultBitmap.SetSource(ms);
          }
 
        //Get the image data
        using (IRandomAccessStream ms = new InMemoryRandomAccessStream())
         {
             try
              {
                  byte[] bytes;
 
                  // Open a stream to copy the image contents to the WriteableBitmap's pixel buffer
                  using (Stream stream = resultBitmap.PixelBuffer.AsStream())
                  {
                      bytes = new byte[(uint)stream.Length];
                      await stream.ReadAsync(bytes, 0, bytes.Length);
                  }
 
                 // Create an encoder with the Jpeg format
                 BitmapEncoder encoder = await   BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, ms);
                   
                 // WriteableBitmap uses BGRA format 
                 encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Ignore, (uint)resultBitmap.PixelWidth, (uint)resultBitmap.PixelHeight, 96, 96, bytes);
 
                 //Terminate the encoder bytes
                 await encoder.FlushAsync();
                    
                 resultArray = new byte[ms.AsStream().Length];
                 await ms.AsStream().ReadAsync(resultArray, 0, resultArray.Length);
             }
             catch (Exception e)
             {
                  System.Diagnostics.Debug.WriteLine(e.Message);
             }
         }
 
         //Store the image into memory stream
         Stream imgStream = new MemoryStream(resultArray);
 
        //Return the Jpeg image as stream
        return imgStream;
 }

通过一些链接:BitmapEncoder FlushAsync()永远不会返回BitmapEncoder FlushAsync抛出参数异常- c#

Answer 1

我们附上了可运行的样品供您参考。请在您那边试一下，然后告诉我们结果。

示例:https://www.syncfusion.com/downloads/support/directtrac/general/ze/uwp_sample - 1957906502