.NET Framework Class Library
GifBitmapDecoder Class

Defines a decoder for Graphics Interchange Format (GIF) encoded images.

Namespace:  System.Windows.Media.Imaging
Assembly:  PresentationCore (in PresentationCore.dll)
Syntax

Visual Basic (Declaration)
Public NotInheritable Class GifBitmapDecoder _
    Inherits BitmapDecoder
Visual Basic (Usage)
Dim instance As GifBitmapDecoder
C#
public sealed class GifBitmapDecoder : BitmapDecoder
Visual C++
public ref class GifBitmapDecoder sealed : public BitmapDecoder
JScript
public final class GifBitmapDecoder extends BitmapDecoder
XAML
You cannot directly create an instance of this class in XAML.
Examples

The following examples show how to decode and encode a Graphics Interchange Format (GIF) image using the specific GifBitmapDecoder and GifBitmapEncoder objects. For the complete sample, see GIF Encoder and Decoder Sample

This example demonstrates how to decode a GIF image using a GifBitmapDecoder from a FileStream.

Visual Basic
' Open a Stream and decode a GIF image
Dim imageStreamSource As New FileStream("tulipfarm.gif", FileMode.Open, FileAccess.Read, FileShare.Read)
Dim decoder As New GifBitmapDecoder(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)
C#
// Open a Stream and decode a GIF image
Stream imageStreamSource = new FileStream("tulipfarm.gif", FileMode.Open, FileAccess.Read, FileShare.Read);
GifBitmapDecoder decoder = new GifBitmapDecoder(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);
Visual C++
// Open a Stream and decode a GIF image
Stream^ imageStreamSource = gcnew FileStream("tulipfarm.gif", FileMode::Open, FileAccess::Read, FileShare::Read);
GifBitmapDecoder^ decoder = gcnew GifBitmapDecoder(imageStreamSource, BitmapCreateOptions::PreservePixelFormat, BitmapCacheOption::Default);
BitmapSource^ bitmapSource = decoder->Frames[0];

// Draw the Image
Image^ myImage = gcnew Image();
myImage->Source = bitmapSource;
myImage->Stretch = Stretch::None;
myImage->Margin = System::Windows::Thickness(20);

This example demonstrates how to encode a BitmapSource into a GIF image using a GifBitmapEncoder.

Visual Basic
Dim width As Integer = 128
Dim height As Integer = width
Dim stride As Integer = CType(width / 8, Integer)
Dim pixels(height * stride) As Byte

' Define the image palette
Dim myPalette As BitmapPalette = BitmapPalettes.WebPalette

' 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.Indexed1, myPalette, pixels, stride)
Dim stream As New FileStream("new.gif", FileMode.Create)
Dim encoder As New GifBitmapEncoder()
Dim myTextBlock As New TextBlock()
myTextBlock.Text = "Codec Author is: " + encoder.CodecInfo.Author.ToString()
encoder.Frames.Add(BitmapFrame.Create(image))
encoder.Save(stream)
C#
int width = 128;
int height = width;
int stride = width / 8;
byte[] pixels = new byte[height * stride];

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

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

BitmapSource image = BitmapSource.Create(
    width,
    height,
    96,
    96,
    PixelFormats.Indexed1,
    myPalette,
    pixels,
    stride);

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

Visual C++
int width = 128;
int height = width;
int stride = width / 8;
array<System::Byte>^ pixels = gcnew array<System::Byte>(height * stride);

// Define the image palette

BitmapPalette^ myPalette = BitmapPalettes::WebPalette;

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

BitmapSource^ image = BitmapSource::Create(
   width,
   height,
   96,
   96,
   PixelFormats::Indexed1,
   myPalette,
   pixels,
   stride);

FileStream^ stream = gcnew FileStream("new.gif", FileMode::Create);
GifBitmapEncoder^ encoder = gcnew GifBitmapEncoder();
TextBlock^ myTextBlock = gcnew TextBlock();
myTextBlock->Text = "Codec Author is: " + encoder->CodecInfo->Author->ToString();
encoder->Frames->Add(BitmapFrame::Create(image));
encoder->Save(stream);

Inheritance Hierarchy

System..::.Object
  System.Windows.Threading..::.DispatcherObject
    System.Windows.Media.Imaging..::.BitmapDecoder
      System.Windows.Media.Imaging..::.GifBitmapDecoder
Thread Safety

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

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.
Version Information

.NET Framework

Supported in: 3.5, 3.0
See Also

Reference

Other Resources

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