Provides access to a metadata query writer that can write metadata to a bitmap image file.
Assembly: PresentationCore (in PresentationCore.dll)
Metadata that is associated with an image is data that describes the image but that is not necessary for display of the image. Each supported bitmap image format handles metadata differently, but the facility for reading and writing metadata is the same.
Windows Presentation Foundation (WPF) supports the following image metadata schemas: Exchangeable image file (Exif), tEXt (PNG Textual Data), image file directory (IFD), International Press Telecommunications Council (IPTC), and Extensible Metadata Platform (XMP).
The following code example demonstrates how to use the method to write metadata to a Portable Network Graphics (PNG) file.
Dim pngStream As New System.IO.FileStream("smiley.png", FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite) Dim pngDecoder As New PngBitmapDecoder(pngStream, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default) Dim pngFrame As BitmapFrame = pngDecoder.Frames(0) Dim pngInplace As InPlaceBitmapMetadataWriter = pngFrame.CreateInPlaceBitmapMetadataWriter() If pngInplace.TrySave() = True Then pngInplace.SetQuery("/Text/Description", "Have a nice day.") End If pngStream.Close()
After the metadata is written, the GetQuery method is used to read that data and emit it as a text string.