SoftwareBitmap and BitmapEncoder in Windows.Graphics.Imaging Namespace

下面的代码创建了一个透明的图片

var bitmap = new SoftwareBitmap(BitmapPixelFormat.Rgba8, 192, 192);
var writer = new DataWriter();
for (int i = 0; i < 192 * 192; i++)
{
    writer.WriteUInt32(0);
}
bitmap.CopyFromBuffer(writer.DetachBuffer());
using var file = File.OpenWrite("icon_background.png");
var encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId, file.AsRandomAccessStream());
encoder.SetSoftwareBitmap(bitmap);
await encoder.FlushAsync();