private void btnOpen_Click( object sender, RoutedEventArgs e )
{
CommonOpenFileDialog openDialog = new CommonOpenFileDialog();
openDialog.ShowPlacesList = true;
openDialog.Multiselect = false;
openDialog.IsFolderPicker = false;
openDialog.AddToMostRecentlyUsedList = true;
openDialog.Filters.Add( new CommonFileDialogFilter( "PNG images", "*.png" ) );
if ( openDialog.ShowDialog( this ) == CommonFileDialogResult.Ok ) {
soureFilePath = openDialog.FileName;
// get comment meta
using ( FileStream fileStream = new FileStream( soureFilePath, FileMode.Open, FileAccess.Read ) ) {
pngReader = new PngReader( fileStream );
// 参考自Hjg.Pngcs的SampleCustomChunk项目
// get last line: this forces loading all chunks
pngReader.ReadChunksOnly();
tblkComment.Text = pngReader.GetMetadata().GetTxtForKey( Key_SemanticInfo );
pngReader.End();
fileStream.Close();
}
image.BeginInit();
image.Source = new BitmapImage( new Uri( soureFilePath ) );
image.EndInit();
}
}
public static void fatalError(String s, PngReader png1)
{
try {
png1.End();
} catch (Exception ) {
}
throw new PngjException(s);
}
private void btnSave_Click( object sender, RoutedEventArgs e )
{
CommonSaveFileDialog saveDialog = new CommonSaveFileDialog();
saveDialog.ShowPlacesList = true;
saveDialog.AddToMostRecentlyUsedList = true;
saveDialog.Filters.Add( new CommonFileDialogFilter( "PNG images", "*.png" ) );
saveDialog.DefaultFileName = DateTime.Now.ToString( "yyyyMMddhhmmss" ) + ".png";
if ( saveDialog.ShowDialog( this ) == CommonFileDialogResult.Ok ) {
using ( FileStream newFileStream = new FileStream( saveDialog.FileName, FileMode.OpenOrCreate, FileAccess.ReadWrite ),
oldFileStream = new FileStream( soureFilePath, FileMode.Open, FileAccess.Read ) ) {
string semanticInfo = @"
sky: blue sky.
heart: cloud heart.
Meaning: It means love|爱|❤.
";
////// Reference: http://code.google.com/p/pngcs/wiki/Overview
// get decoder
pngReader = new PngReader( oldFileStream );
// create encoder
pngWriter = new PngWriter( newFileStream, pngReader.ImgInfo );
// copy
int chunkBehav = Hjg.Pngcs.Chunks.ChunkCopyBehaviour.COPY_ALL; // tell to copy all 'safe' chunks
pngWriter.CopyChunksFirst( pngReader, chunkBehav ); // copy some metadata from reader
int channels = pngReader.ImgInfo.Channels;
if ( channels < 3 )
throw new Exception( "This example works only with RGB/RGBA images" );
for ( int row = 0; row < pngReader.ImgInfo.Rows; row++ ) {
ImageLine l1 = pngReader.ReadRow( row ); // format: RGBRGB... or RGBARGBA...
pngWriter.WriteRow( l1, row );
}
pngWriter.CopyChunksLast( pngReader, chunkBehav ); // metadata after the image pixels? can happen
// app info
pngWriter.GetMetadata().SetText( Hjg.Pngcs.Chunks.PngChunkTextVar.KEY_Software, "Semantic Image" );
// semantic info
Hjg.Pngcs.Chunks.PngChunk chunk = pngWriter.GetMetadata().SetText( Key_SemanticInfo, semanticInfo, false, false );
chunk.Priority = true;
pngWriter.End(); // dont forget this
pngReader.End();
oldFileStream.Close();
newFileStream.Close();
}
}
}