问如何调整SoftwareBitmap的大小？

EN

private async Task<ImageSource> ProcessImageAsync(StorageFile ImageFile)
    {
        if (ImageFile == null)
            throw new ArgumentNullException("ImageFile cannot be null.");

        //The new size of processed image.
        const int side = 100;

        //Initialize bitmap transformations to be applied to the image.
        var transform = new BitmapTransform() { ScaledWidth = side, ScaledHeight = side, InterpolationMode = BitmapInterpolationMode.Cubic };

        //Get image pixels.
        var stream = await ImageFile.OpenStreamForReadAsync();
        var decoder = await BitmapDecoder.CreateAsync(stream.AsRandomAccessStream());
        var pixelData = await decoder.GetPixelDataAsync(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Premultiplied, transform, ExifOrientationMode.RespectExifOrientation, ColorManagementMode.ColorManageToSRgb);
        var pixels = pixelData.DetachPixelData();

        //Initialize writable bitmap.
        var wBitmap = new WriteableBitmap((int)decoder.PixelWidth, (int)decoder.PixelHeight);
        await wBitmap.SetSourceAsync(stream.AsRandomAccessStream());

        //Create a software bitmap from the writable bitmap's pixel buffer.
        var sBitmap = SoftwareBitmap.CreateCopyFromBuffer(wBitmap.PixelBuffer, BitmapPixelFormat.Bgra8, side, side, BitmapAlphaMode.Premultiplied);

        //Create software bitmap source.
        var sBitmapSource = new SoftwareBitmapSource();
        await sBitmapSource.SetBitmapAsync(sBitmap);

        return sBitmapSource;
    }

    private async Task<SoftwareBitmap> ResizeSoftwareBitmap(SoftwareBitmap softwareBitmap, double scaleFactor)
    {
        var resourceCreator = CanvasDevice.GetSharedDevice();
        var canvasBitmap = CanvasBitmap.CreateFromSoftwareBitmap(resourceCreator, softwareBitmap);
        var canvasRenderTarget = new CanvasRenderTarget(resourceCreator, (int)(softwareBitmap.PixelWidth * scaleFactor), (int)(softwareBitmap.PixelHeight * scaleFactor), 96);

        using (var cds = canvasRenderTarget.CreateDrawingSession())
        {
            cds.DrawImage(canvasBitmap, canvasRenderTarget.Bounds);
        }

        var pixelBytes = canvasRenderTarget.GetPixelBytes();

        var writeableBitmap = new WriteableBitmap((int)(softwareBitmap.PixelWidth * scaleFactor), (int)(softwareBitmap.PixelHeight * scaleFactor));
        using (var stream = writeableBitmap.PixelBuffer.AsStream())
        {
            await stream.WriteAsync(pixelBytes, 0, pixelBytes.Length);
        }

        var scaledSoftwareBitmap = new SoftwareBitmap(BitmapPixelFormat.Bgra8, (int)(softwareBitmap.PixelWidth * scaleFactor), (int)(softwareBitmap.PixelHeight * scaleFactor));
        scaledSoftwareBitmap.CopyFromBuffer(writeableBitmap.PixelBuffer);

        return scaledSoftwareBitmap;
    }

public static SoftwareBitmap Resize(this SoftwareBitmap softwareBitmap, float newWidth, float newHeight)
{
    using (var resourceCreator = CanvasDevice.GetSharedDevice())
    using (var canvasBitmap = CanvasBitmap.CreateFromSoftwareBitmap(resourceCreator, softwareBitmap))
    using (var canvasRenderTarget = new CanvasRenderTarget(resourceCreator, newWidth, newHeight, canvasBitmap.Dpi))
    using (var drawingSession = canvasRenderTarget.CreateDrawingSession())
    using (var scaleEffect = new ScaleEffect())
    {
        scaleEffect.Source = canvasBitmap;
        scaleEffect.Scale = new System.Numerics.Vector2(newWidth / softwareBitmap.PixelWidth, newHeight / softwareBitmap.PixelHeight);
        drawingSession.DrawImage(scaleEffect);
        drawingSession.Flush();
        return SoftwareBitmap.CreateCopyFromBuffer(canvasRenderTarget.GetPixelBytes().AsBuffer(), BitmapPixelFormat.Bgra8, (int)newWidth, (int)newHeight, BitmapAlphaMode.Premultiplied);
    }
}