我试图写一个函数，将调整图像大小和压缩它使用压缩质量值。我发现了一些有用的信息here和here和here，但我仍然很困惑。
我正在使用依赖服务，并成功地为iOS和Android完成了它。下面是我在iOS上使用的代码。

iOS

public byte[] DecodeImage(byte[] imgBytes, int regWidth, int regHeight, int compressionQuality)
{
    try
    {
        NSData data = NSData.FromArray(imgBytes);
        var image = UIImage.LoadFromData(data);
        
        data = image.AsJPEG((nfloat) compressionQuality / 100);
        byte[] bytes = new byte[data.Length];
        System.Runtime.InteropServices.Marshal.Copy(data.Bytes, bytes, 0, Convert.ToInt32(data.Length));
        return bytes;
    }
    catch (Exception ex)
    {
        return null;
    }
}

我想在我的UWP项目中为依赖服务复制相同的功能，任何帮助都将不胜感激。
这是我目前所拥有的，但它不起作用。

public async Task<byte[]> DecodeImageAsync(string fileUri, int regWidth, int regHeight, int compressionQuality)
{
    byte[] returnVal;

    StorageFile file = await StorageFile.GetFileFromPathAsync(fileUri);

    using (IRandomAccessStream stream = await file.OpenAsync(FileAccessMode.Read))
    {
        BitmapDecoder decoder = await BitmapDecoder.CreateAsync(stream); //ConfigureAwait(false).;

        var qualityNum = (float)compressionQuality / 100;
        var propertySet = new BitmapPropertySet();
        var qualityValue = new BitmapTypedValue(
            qualityNum, // Maximum quality
            Windows.Foundation.PropertyType.Single
        );
        propertySet.Add("ImageQuality", qualityValue);

        var resizedStream = new InMemoryRandomAccessStream();

        BitmapEncoder en = await BitmapEncoder.CreateForTranscodingAsync(resizedStream, decoder);
        BitmapEncoder encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, stream,
            propertySet);

        double widthRatio = (double) regWidth / decoder.PixelWidth;
        double heightRatio = (double) regHeight / decoder.PixelHeight;

        double scaleRatio = Math.Min(widthRatio, heightRatio);

        if (regWidth == 0)
            scaleRatio = heightRatio;

        if (regHeight == 0)
            scaleRatio = widthRatio;

        uint aspectHeight = (uint) Math.Floor(decoder.PixelHeight * scaleRatio);
        uint aspectWidth = (uint) Math.Floor(decoder.PixelWidth * scaleRatio);

        encoder.BitmapTransform.InterpolationMode = BitmapInterpolationMode.Linear;

        encoder.BitmapTransform.ScaledHeight = aspectHeight;
        encoder.BitmapTransform.ScaledWidth = aspectWidth;

        returnVal = new byte[stream.Size];
        await encoder.FlushAsync();
        stream.Seek(0);
        returnVal = new byte[stream.Size];
        var dr = new DataReader(stream.GetInputStreamAt(0));
        await dr.LoadAsync((uint)stream.Size);
        dr.ReadBytes(returnVal);
    }
    return returnVal;
}

任何想法，我可以改变代码，以调整大小以及压缩图像将不胜感激。