如何在 UWP C# 中将 SVG 转换为 WriteableBitmap

Question

我们可以从 UWP 中的 1703 加载 SVG。 谁能提供一种机制，如何将 SVG 转换为 C# UWP 中的 WriteableBitmap。

Answer 1

Unfortunately, there is no such api could covert SVG to WriteableBitmap image directly, Because when we convert file to WriteableBitmap we need use BitmapDecoder class like the following, but BitmapDecoder does not support svg type.

private static async Task<WriteableBitmap> OpenWriteableBitmapFile(StorageFile file)
{
    using (IRandomAccessStream stream = await file.OpenAsync(FileAccessMode.Read))
    {
        BitmapDecoder decoder = await BitmapDecoder.CreateAsync(stream);
        WriteableBitmap image = new WriteableBitmap((int)decoder.PixelWidth, (int)decoder.PixelHeight);
        image.SetSource(stream);

        return image;
    }
}

目前我们有一个解决方法，使用RenderTargetBitmap来呈现您的图像控件并将RenderTargetBitmap转换为WriteableBitmap并使用以下方法。

private async void RenderTargetBitmapToWriteableBitmap(UIElement element)
{
    var bitmap = new RenderTargetBitmap();
    await bitmap.RenderAsync(element);
    var pixelBuffer = await bitmap.GetPixelsAsync();
    byte[] pixels = pixelBuffer.ToArray();
    var wb = new WriteableBitmap((int)bitmap.PixelWidth, (int)bitmap.PixelHeight);
    using (Stream stream = wb.PixelBuffer.AsStream())
    {
        await stream.WriteAsync(pixels, 0, pixels.Length);
    }
}