对于那些有同样问题的人,我做了以下工作,并很乐意接受改进意见。
public static SKBitmap HandleOrientation(SKBitmap bitmap, SKCodecOrigin orientation)
{
SKBitmap rotated;
switch (orientation)
{
case SKCodecOrigin.BottomRight:
using (var surface = new SKCanvas(bitmap))
{
surface.RotateDegrees(180, bitmap.Width / 2, bitmap.Height / 2);
surface.DrawBitmap(bitmap.Copy(), 0, 0);
}
return bitmap;
case SKCodecOrigin.RightTop:
rotated = new SKBitmap(bitmap.Height, bitmap.Width);
using (var surface = new SKCanvas(rotated))
{
surface.Translate(rotated.Width, 0);
surface.RotateDegrees(90);
surface.DrawBitmap(bitmap, 0, 0);
}
return rotated;
case SKCodecOrigin.LeftBottom:
rotated = new SKBitmap(bitmap.Height, bitmap.Width);
using (var surface = new SKCanvas(rotated))
{
surface.Translate(0, rotated.Height);
surface.RotateDegrees(270);
surface.DrawBitmap(bitmap, 0, 0);
}
return rotated;
default:
return bitmap;
}
然后使用以下方法获取原始方向。
// TODO: Improve this.. I do not know how to "reset"
// the inputStream, so new it up twice. :/
using (var inputStream = new SKManagedStream(imageIn))
{
using (var codec = SKCodec.Create(inputStream))
{
orientation = codec.Origin;
}
}
…………
然后
SKBitmap orientedWExif = HandleOrientation(resized, orientation);