the problem has been solved by using CsXMpToolKit.dll ,which is the best option to fetch the metadat from any type of file.
To change the metatags of PNG Image files
题
I am using PngCs dll to fetch the chunk data for Png image file in asp.net, I am able to do that but now I want to update the chunk data for that PNG.
I used PngWriter but it is creating whole new file without inheriting chunk data.
PngReader pngr = FileHelper.CreatePngReader(path);
pngr.GetMetadata().GetTxtForKey(PngChunkITXT.KEY_Title);
Response.Write(pngr.GetMetadata().GetTxtForKey(PngChunkITXT.KEY_Title));
Below code is for writing new Png Image through PngWriter ,I want embed new itxt chunk while creating new file.
PngReader pngr = FileHelper.CreatePngReader(origFilename); // or you can use the constructor
PngWriter pngw = FileHelper.CreatePngWriter(destFilename, pngr.ImgInfo, true); // idem
Console.WriteLine(pngr.ToString()); // just information
int chunkBehav = ChunkCopyBehaviour.COPY_ALL_SAFE; // tell to copy all 'safe' chunks
pngw.CopyChunksFirst(pngr, chunkBehav); // copy some metadata from reader
for (int row = 0; row < pngr.ImgInfo.Rows; row++)
{
ImageLine l1 = pngr.ReadRowInt(row); // format: RGBRGB... or RGBARGBA...
pngw.WriteRow(l1, row);
}
pngw.CopyChunksLast(pngr, chunkBehav); // metadata after the image pixels? can happen
pngw.End(); // dont forget this
pngr.End();
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解决方案 2
其他提示
Try this
PngReader pngr = FileHelper.CreatePngReader(origFilename);
PngWriter pngw = FileHelper.CreatePngWriter(destFilename, pngr.ImgInfo, true);
pngw.CopyChunksFirst(pngr, ChunkCopyBehaviour.COPY_ALL);
pngw.GetMetadata().SetText(myKey, myText,false,false); // provide your own data
for (int row = 0; row < pngr.ImgInfo.Rows; row++) {
ImageLine l1 = pngr.ReadRowInt(row);
pngw.WriteRow(l1, row);
}
pngw.CopyChunksLast(pngr, ChunkCopyBehaviour.COPY_ALL);
pngw.End(); // dont forget this
pngr.End();
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