PngBitmapEncoder Class
Defines an encoder that is used to encode Portable Network Graphics (PNG) format images.
Assembly: PresentationCore (in PresentationCore.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation
Portable Network Graphics (PNG) format bitmaps support frame level metadata. They do not support preview, global thumbnails, frame level thumbnails, global metadata, or multiple frames.
Encoding does not work in partial trust. See Windows Presentation Foundation Partial Trust Security for information on partial trust.
The following examples show how to decode and encode a Portable Network Graphics (PNG) image using the specific PngBitmapDecoder and PngBitmapEncoder objects. For the complete sample, see PNG Encoder and Decoder Sample.
This example demonstrates how to decode a PNG image using a PngBitmapDecoder from a FileStream.
' Open a Stream and decode a PNG image Dim imageStreamSource As New FileStream("smiley.png", FileMode.Open, FileAccess.Read, FileShare.Read) Dim decoder As New PngBitmapDecoder(imageStreamSource, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default) Dim bitmapSource As BitmapSource = decoder.Frames(0) ' Draw the Image Dim myImage As New Image() myImage.Source = bitmapSource myImage.Stretch = Stretch.None myImage.Margin = New Thickness(20)
This example demonstrates how to encode a BitmapSource into a PNG image using a PngBitmapEncoder.
Dim width As Integer = 128 Dim height As Integer = 128 Dim stride As Integer = width Dim pixels(height * stride) As Byte ' Define the image palette Dim myPalette As BitmapPalette = BitmapPalettes.Halftone256 ' Creates a new empty image with the pre-defined palette Dim image As BitmapSource = System.Windows.Media.Imaging.BitmapSource.Create( _ width, height, 96, 96, PixelFormats.Indexed8, myPalette, pixels, stride) Dim stream As New FileStream("new.png", FileMode.Create) Dim encoder As New PngBitmapEncoder() Dim myTextBlock As New TextBlock() myTextBlock.Text = "Codec Author is: " + encoder.CodecInfo.Author.ToString() encoder.Interlace = PngInterlaceOption.On encoder.Frames.Add(BitmapFrame.Create(image)) encoder.Save(stream)
System.Windows.Threading.DispatcherObject
System.Windows.Media.Imaging.BitmapEncoder
System.Windows.Media.Imaging.PngBitmapEncoder
Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.