private static GifFile DecodeGifFile(Uri uri)
{
Stream stream = null;
if (uri.Scheme == PackUriHelper.UriSchemePack)
{
StreamResourceInfo sri;
if (uri.Authority == "siteoforigin:,,,")
{
sri = Application.GetRemoteStream(uri);
}
else
{
sri = Application.GetResourceStream(uri);
}
if (sri != null)
{
stream = sri.Stream;
}
}
else
{
WebClient wc = new WebClient();
stream = wc.OpenRead(uri);
}
if (stream != null)
{
using (stream)
{
return(GifFile.ReadGifFile(stream, true));
}
}
return(null);
}
private static BitmapDecoder GetDecoder(BitmapSource image, out GifFile gifFile)
{
gifFile = null;
BitmapDecoder decoder = null;
Stream stream = null;
Uri uri = null;
BitmapCreateOptions createOptions = BitmapCreateOptions.None;
if (image is BitmapImage bmp)
{
createOptions = bmp.CreateOptions;
if (bmp.StreamSource != null)
{
stream = bmp.StreamSource;
}
else if (bmp.UriSource != null)
{
uri = bmp.UriSource;
if (bmp.BaseUri != null && !uri.IsAbsoluteUri)
{
uri = new Uri(bmp.BaseUri, uri);
}
}
}
else
{
if (image is BitmapFrame frame)
{
decoder = frame.Decoder;
Uri.TryCreate(frame.BaseUri, frame.ToString(), out uri);
}
}
if (decoder == null)
{
if (stream != null)
{
stream.Position = 0;
decoder = BitmapDecoder.Create(stream, createOptions, BitmapCacheOption.OnLoad);
}
else if (uri != null && uri.IsAbsoluteUri)
{
decoder = BitmapDecoder.Create(uri, createOptions, BitmapCacheOption.OnLoad);
}
}
if (decoder is GifBitmapDecoder && !CanReadNativeMetadata(decoder))
{
if (stream != null)
{
stream.Position = 0;
gifFile = GifFile.ReadGifFile(stream, true);
}
else if (uri != null)
{
gifFile = DecodeGifFile(uri);
}
else
{
throw new InvalidOperationException("Can't get URI or Stream from the source. AnimatedSource should be either a BitmapImage, or a BitmapFrame constructed from a URI.");
}
}
if (decoder == null)
{
throw new InvalidOperationException("Can't get a decoder from the source. AnimatedSource should be either a BitmapImage or a BitmapFrame.");
}
return(decoder);
}
