GifBitmapDecoder 构造函数

定义

命名空间:

System.Windows.Media.Imaging

程序集:

PresentationCore.dll

初始化 GifBitmapDecoder 的新实例。

重载

GifBitmapDecoder(Stream, BitmapCreateOptions, BitmapCacheOption)	从指定的文件流，用指定的 createOptions 和 cacheOption 初始化 GifBitmapDecoder 类的一个新实例。
GifBitmapDecoder(Uri, BitmapCreateOptions, BitmapCacheOption)	从指定的 GifBitmapDecoder，用指定的 createOptions 和 cacheOption 初始化 Uri 的一个新实例。

GifBitmapDecoder(Stream, BitmapCreateOptions, BitmapCacheOption)

从指定的文件流，用指定的 createOptions 和 cacheOption 初始化 GifBitmapDecoder 类的一个新实例。

public:
 GifBitmapDecoder(System::IO::Stream ^ bitmapStream, System::Windows::Media::Imaging::BitmapCreateOptions createOptions, System::Windows::Media::Imaging::BitmapCacheOption cacheOption);

[System.Security.SecurityCritical]
public GifBitmapDecoder (System.IO.Stream bitmapStream, System.Windows.Media.Imaging.BitmapCreateOptions createOptions, System.Windows.Media.Imaging.BitmapCacheOption cacheOption);

public GifBitmapDecoder (System.IO.Stream bitmapStream, System.Windows.Media.Imaging.BitmapCreateOptions createOptions, System.Windows.Media.Imaging.BitmapCacheOption cacheOption);

[<System.Security.SecurityCritical>]
new System.Windows.Media.Imaging.GifBitmapDecoder : System.IO.Stream * System.Windows.Media.Imaging.BitmapCreateOptions * System.Windows.Media.Imaging.BitmapCacheOption -> System.Windows.Media.Imaging.GifBitmapDecoder

new System.Windows.Media.Imaging.GifBitmapDecoder : System.IO.Stream * System.Windows.Media.Imaging.BitmapCreateOptions * System.Windows.Media.Imaging.BitmapCacheOption -> System.Windows.Media.Imaging.GifBitmapDecoder

Public Sub New (bitmapStream As Stream, createOptions As BitmapCreateOptions, cacheOption As BitmapCacheOption)

参数

bitmapStream

Stream

要解码的位图流。

createOptions

BitmapCreateOptions

位图图像的初始化选项。

cacheOption

BitmapCacheOption

用于位图图像的缓存方法。

属性

SecurityCriticalAttribute

例外

ArgumentNullException

bitmapStream 值为 null。

FileFormatException

bitmapStream这不是图形交换格式 (GIF) 编码图像。

示例

下面的代码示例演示如何从文件流创建和使用 GifBitmapDecoder 实例。 解码的图像用作控件的 Image 源。

// 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);

// 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);

' 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)

注解

OnLoad如果要在创建解码器后关闭bitmapStream缓存选项，请使用缓存选项。 默认 OnDemand 缓存选项将保留对流的访问，直到需要位图，并由垃圾回收器处理清理。

GifBitmapDecoder(Uri, BitmapCreateOptions, BitmapCacheOption)

从指定的 GifBitmapDecoder，用指定的 createOptions 和 cacheOption 初始化 Uri 的一个新实例。

public:
 GifBitmapDecoder(Uri ^ bitmapUri, System::Windows::Media::Imaging::BitmapCreateOptions createOptions, System::Windows::Media::Imaging::BitmapCacheOption cacheOption);

[System.Security.SecurityCritical]
public GifBitmapDecoder (Uri bitmapUri, System.Windows.Media.Imaging.BitmapCreateOptions createOptions, System.Windows.Media.Imaging.BitmapCacheOption cacheOption);

public GifBitmapDecoder (Uri bitmapUri, System.Windows.Media.Imaging.BitmapCreateOptions createOptions, System.Windows.Media.Imaging.BitmapCacheOption cacheOption);

[<System.Security.SecurityCritical>]
new System.Windows.Media.Imaging.GifBitmapDecoder : Uri * System.Windows.Media.Imaging.BitmapCreateOptions * System.Windows.Media.Imaging.BitmapCacheOption -> System.Windows.Media.Imaging.GifBitmapDecoder

new System.Windows.Media.Imaging.GifBitmapDecoder : Uri * System.Windows.Media.Imaging.BitmapCreateOptions * System.Windows.Media.Imaging.BitmapCacheOption -> System.Windows.Media.Imaging.GifBitmapDecoder

Public Sub New (bitmapUri As Uri, createOptions As BitmapCreateOptions, cacheOption As BitmapCacheOption)

参数

bitmapUri

Uri

Uri，它标识要解码的位图。

createOptions

BitmapCreateOptions

位图图像的初始化选项。

cacheOption

BitmapCacheOption

用于位图图像的缓存方法。

属性

SecurityCriticalAttribute

例外

ArgumentNullException

bitmapUri 值为 null。

FileFormatException

bitmapUri这不是图形交换格式 (GIF) 编码图像。

示例

下面的代码示例演示如何创建实例并使用 GifBitmapDecoder a Uri. 解码的图像用作控件的 Image 源。

// Open a Uri and decode a GIF image
System::Uri^ myUri = gcnew System::Uri("tulipfarm.gif", UriKind::RelativeOrAbsolute);
GifBitmapDecoder^ decoder2 = gcnew GifBitmapDecoder(myUri, BitmapCreateOptions::PreservePixelFormat, BitmapCacheOption::Default);
BitmapSource^ bitmapSource2 = decoder2->Frames[0];

// Draw the Image
Image^ myImage2 = gcnew Image();
myImage2->Source = bitmapSource2;
myImage2->Stretch = Stretch::None;
myImage2->Margin = System::Windows::Thickness(20);

// Open a Uri and decode a GIF image
Uri myUri = new Uri("tulipfarm.gif", UriKind.RelativeOrAbsolute);
GifBitmapDecoder decoder2 = new GifBitmapDecoder(myUri, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default);
BitmapSource bitmapSource2 = decoder2.Frames[0];

// Draw the Image
Image myImage2 = new Image();
myImage2.Source = bitmapSource2;
myImage2.Stretch = Stretch.None;
myImage2.Margin = new Thickness(20);

' Open a Uri and decode a GIF image
Dim myUri As New Uri("tulipfarm.gif", UriKind.RelativeOrAbsolute)
Dim decoder2 As New GifBitmapDecoder(myUri, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default)
Dim bitmapSource2 As BitmapSource = decoder2.Frames(0)

' Draw the Image
Dim myImage2 As New Image()
myImage2.Source = bitmapSource2
myImage2.Stretch = Stretch.None
myImage2.Margin = New Thickness(20)