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PngBitmapEncoder Class

Defines an encoder that is used to encode Portable Network Graphics (PNG) format images.

Namespace:  System.Windows.Media.Imaging
Assembly:  PresentationCore (in PresentationCore.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation

public sealed class PngBitmapEncoder : BitmapEncoder
This managed class is not typically used in XAML.

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
Stream imageStreamSource = new FileStream("smiley.png", FileMode.Open, FileAccess.Read, FileShare.Read);
PngBitmapDecoder decoder = new PngBitmapDecoder(imageStreamSource, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default);
BitmapSource bitmapSource = decoder.Frames[0];

// Draw the Image
Image myImage = 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.

int width = 128;
int height = 128;
int stride = width;
byte[] pixels = new byte[height * stride];

// Define the image palette
BitmapPalette myPalette = BitmapPalettes.Halftone256;

// Creates a new empty image with the pre-defined palette

BitmapSource image = BitmapSource.Create(
    width,
    height,
    96,
    96,
    PixelFormats.Indexed8,
    myPalette,
    pixels,
    stride);

FileStream stream = new FileStream("new.png", FileMode.Create);
PngBitmapEncoder encoder = new PngBitmapEncoder();
TextBlock myTextBlock = new TextBlock();
myTextBlock.Text = "Codec Author is: " + encoder.CodecInfo.Author.ToString();
encoder.Interlace = PngInterlaceOption.On;
encoder.Frames.Add(BitmapFrame.Create(image));
encoder.Save(stream);

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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.

.NET Framework

Supported in: 3.5, 3.0

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