C#编辑图像文件EXIF信息

 private void setImageTag(string imgFile, string tagFile, string imgTag, string imgTitle)
 {
     uint padding = ;
     if (File.Exists(imgFile))
     {
         BitmapDecoder decoder = null;
         // load the jpg file with a JpegBitmapDecoder
         using (Stream jpegStreamIn = File.Open(imgFile, FileMode.Open, FileAccess.ReadWrite, FileShare.None))
         {
             decoder = new JpegBitmapDecoder(jpegStreamIn, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.OnLoad);
         }
         if (decoder != null)
         {
             BitmapFrame bitmapFrame = decoder.Frames[];
             if (bitmapFrame != null)
             {
                 // the size of the metadata has been increased and we can't save it
                 BitmapMetadata metaData = (BitmapMetadata)bitmapFrame.Metadata.Clone();
                 if (metaData != null)
                 {
                     // Add padding
                     metaData.SetQuery("/app1/ifd/PaddingSchema:Padding", padding);
                     metaData.Title = imgTitle;
                     List<string> taglist = new List<string>();
                     taglist.Add(imgTag);
                     metaData.Keywords = new System.Collections.ObjectModel.ReadOnlyCollection<string>(taglist);
                     // get an encoder to create a new jpg file with the addit'l metadata.
                     JpegBitmapEncoder encoder = new JpegBitmapEncoder();
                     encoder.Frames.Add(BitmapFrame.Create(bitmapFrame, bitmapFrame.Thumbnail, metaData, bitmapFrame.ColorContexts));
                     using (Stream jpegStreamOut = File.Open(tagFile, FileMode.CreateNew, FileAccess.ReadWrite))
                     {
                         encoder.Save(jpegStreamOut);
                     }
                 }
             }
         }
     }
 }

其中22行，添加PADDING是不能少的，否则编辑信息保存不上。