我使用这个库:https://github.com/XamlAnimatedGif/WpfAnimatedGif

首先，将库安装到项目中(使用包管理器控制台):

    PM > Install-Package WpfAnimatedGif

然后，使用这个片段到XAML文件:

    <Window x:Class="WpfAnimatedGif.Demo.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:gif="http://wpfanimatedgif.codeplex.com"
        Title="MainWindow" Height="350" Width="525">
        <Grid>
            <Image gif:ImageBehavior.AnimatedSource="Images/animated.gif" />
        ...

希望能有所帮助。

来源:https://github.com/XamlAnimatedGif/WpfAnimatedGif

添加到主响应，建议使用WpfAnimatedGif，你必须在最后添加以下行，如果你是交换图像与Gif，以确保动画实际执行:

ImageBehavior.SetRepeatBehavior(img, new RepeatBehavior(0));
ImageBehavior.SetRepeatBehavior(img, RepeatBehavior.Forever);

所以你的代码看起来像这样:

var image = new BitmapImage();
image.BeginInit();
image.UriSource = new Uri(fileName);
image.EndInit();
ImageBehavior.SetAnimatedSource(img, image);
ImageBehavior.SetRepeatBehavior(img, new RepeatBehavior(0));
ImageBehavior.SetRepeatBehavior(img, RepeatBehavior.Forever);

这个小程序怎么样: 背后的代码:

public MainWindow()
{
  InitializeComponent();
  Files = Directory.GetFiles(@"I:\images");
  this.DataContext= this;
}
public string[] Files
{get;set;}

XAML:

<Window x:Class="PicViewer.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="175" />
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>
        <ListBox x:Name="lst" ItemsSource="{Binding Path=Files}"/>
        <MediaElement Grid.Column="1" LoadedBehavior="Play" Source="{Binding ElementName=lst, Path=SelectedItem}" Stretch="None"/>
    </Grid>
</Window>

我修改了迈克·艾希瓦的代码，让它运行得更好。你可以使用它与1帧jpg png bmp或多帧gif。如果你想绑定uri到控件，绑定UriSource属性，或者你想绑定任何内存流，你绑定Source属性，这是一个BitmapImage。

    /// <summary> 
/// Элемент управления "Изображения", поддерживающий анимированные GIF. 
/// </summary> 
public class AnimatedImage : Image
{
    static AnimatedImage()
    {
        DefaultStyleKeyProperty.OverrideMetadata(typeof(AnimatedImage), new FrameworkPropertyMetadata(typeof(AnimatedImage)));
    }

    #region Public properties

    /// <summary> 
    /// Получает/устанавливает номер текущего кадра. 
    /// </summary> 
    public int FrameIndex
    {
        get { return (int)GetValue(FrameIndexProperty); }
        set { SetValue(FrameIndexProperty, value); }
    }

    /// <summary>
    /// Get the BitmapFrame List.
    /// </summary>
    public List<BitmapFrame> Frames { get; private set; }

    /// <summary>
    /// Get or set the repeatBehavior of the animation when source is gif formart.This is a dependency object.
    /// </summary>
    public RepeatBehavior AnimationRepeatBehavior
    {
        get { return (RepeatBehavior)GetValue(AnimationRepeatBehaviorProperty); }
        set { SetValue(AnimationRepeatBehaviorProperty, value); }
    }

    public new BitmapImage Source
    {
        get { return (BitmapImage)GetValue(SourceProperty); }
        set { SetValue(SourceProperty, value); }
    }

    public Uri UriSource
    {
        get { return (Uri)GetValue(UriSourceProperty); }
        set { SetValue(UriSourceProperty, value); }
    }

    #endregion

    #region Protected interface

    /// <summary> 
    /// Provides derived classes an opportunity to handle changes to the Source property. 
    /// </summary> 
    protected virtual void OnSourceChanged(DependencyPropertyChangedEventArgs e)
    {
        ClearAnimation();
        BitmapImage source;
        if (e.NewValue is Uri)
        {
            source = new BitmapImage();
            source.BeginInit();
            source.UriSource = e.NewValue as Uri;
            source.CacheOption = BitmapCacheOption.OnLoad;
            source.EndInit();
        }
        else if (e.NewValue is BitmapImage)
        {
            source = e.NewValue as BitmapImage;
        }
        else
        {
            return;
        }
        BitmapDecoder decoder;
        if (source.StreamSource != null)
        {
            decoder = BitmapDecoder.Create(source.StreamSource, BitmapCreateOptions.DelayCreation, BitmapCacheOption.OnLoad);
        }
        else if (source.UriSource != null)
        {
            decoder = BitmapDecoder.Create(source.UriSource, BitmapCreateOptions.DelayCreation, BitmapCacheOption.OnLoad);
        }
        else
        {
            return;
        }
        if (decoder.Frames.Count == 1)
        {
            base.Source = decoder.Frames[0];
            return;
        }

        this.Frames = decoder.Frames.ToList();

        PrepareAnimation();
    }

    #endregion

    #region Private properties

    private Int32Animation Animation { get; set; }
    private bool IsAnimationWorking { get; set; }

    #endregion

    #region Private methods

    private void ClearAnimation()
    {
        if (Animation != null)
        {
            BeginAnimation(FrameIndexProperty, null);
        }

        IsAnimationWorking = false;
        Animation = null;
        this.Frames = null;
    }

    private void PrepareAnimation()
    {
        Animation =
            new Int32Animation(
                0,
                this.Frames.Count - 1,
                new Duration(
                    new TimeSpan(
                        0,
                        0,
                        0,
                        this.Frames.Count / 10,
                        (int)((this.Frames.Count / 10.0 - this.Frames.Count / 10) * 1000))))
            {
                RepeatBehavior = RepeatBehavior.Forever
            };

        base.Source = this.Frames[0];
        BeginAnimation(FrameIndexProperty, Animation);
        IsAnimationWorking = true;
    }

    private static void ChangingFrameIndex
        (DependencyObject dp, DependencyPropertyChangedEventArgs e)
    {
        AnimatedImage animatedImage = dp as AnimatedImage;

        if (animatedImage == null || !animatedImage.IsAnimationWorking)
        {
            return;
        }

        int frameIndex = (int)e.NewValue;
        ((Image)animatedImage).Source = animatedImage.Frames[frameIndex];
        animatedImage.InvalidateVisual();
    }

    /// <summary> 
    /// Handles changes to the Source property. 
    /// </summary> 
    private static void OnSourceChanged
        (DependencyObject dp, DependencyPropertyChangedEventArgs e)
    {
        ((AnimatedImage)dp).OnSourceChanged(e);
    }

    #endregion

    #region Dependency Properties

    /// <summary> 
    /// FrameIndex Dependency Property 
    /// </summary> 
    public static readonly DependencyProperty FrameIndexProperty =
        DependencyProperty.Register(
            "FrameIndex",
            typeof(int),
            typeof(AnimatedImage),
            new UIPropertyMetadata(0, ChangingFrameIndex));

    /// <summary> 
    /// Source Dependency Property 
    /// </summary> 
    public new static readonly DependencyProperty SourceProperty =
        DependencyProperty.Register(
            "Source",
            typeof(BitmapImage),
            typeof(AnimatedImage),
            new FrameworkPropertyMetadata(
                null,
                FrameworkPropertyMetadataOptions.AffectsRender |
                FrameworkPropertyMetadataOptions.AffectsMeasure,
                OnSourceChanged));

    /// <summary>
    /// AnimationRepeatBehavior Dependency Property
    /// </summary>
    public static readonly DependencyProperty AnimationRepeatBehaviorProperty =
        DependencyProperty.Register(
        "AnimationRepeatBehavior",
        typeof(RepeatBehavior),
        typeof(AnimatedImage),
        new PropertyMetadata(null));

    public static readonly DependencyProperty UriSourceProperty =
        DependencyProperty.Register(
        "UriSource",
        typeof(Uri),
        typeof(AnimatedImage),
                new FrameworkPropertyMetadata(
                null,
                FrameworkPropertyMetadataOptions.AffectsRender |
                FrameworkPropertyMetadataOptions.AffectsMeasure,
                OnSourceChanged));

    #endregion
}

这是一个自定义控件。您需要在WPF应用程序项目中创建它，并在样式中删除模板覆盖。

我无法让这个问题最流行的答案(上面由达里奥提出)正常工作。结果是奇怪的、起伏不定的动画和奇怪的工件。 目前为止我找到的最佳解决方案: https://github.com/XamlAnimatedGif/WpfAnimatedGif

你可以用NuGet安装它

WpfAnimatedGif安装包

并使用它，在一个新的名称空间的窗口，你想添加gif图像，并使用它如下所示

<Window x:Class="MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:gif="http://wpfanimatedgif.codeplex.com" <!-- THIS NAMESPACE -->
    Title="MainWindow" Height="350" Width="525">

<Grid>
    <!-- EXAMPLE USAGE BELOW -->
    <Image gif:ImageBehavior.AnimatedSource="Images/animated.gif" />

这个包非常简洁，你可以像下面这样设置一些属性

<Image gif:ImageBehavior.RepeatBehavior="3x"
       gif:ImageBehavior.AnimatedSource="Images/animated.gif" />

你也可以在你的代码中使用它:

var image = new BitmapImage();
image.BeginInit();
image.UriSource = new Uri(fileName);
image.EndInit();
ImageBehavior.SetAnimatedSource(img, image);

编辑:Silverlight支持

根据josh2112的评论，如果你想在Silverlight项目中添加GIF动画支持，请使用github.com/XamlAnimatedGif/XamlAnimatedGif

检查我的代码，我希望这对你有帮助:)

         public async Task GIF_Animation_Pro(string FileName,int speed,bool _Repeat)
                    {
    int ab=0;
                        var gif = GifBitmapDecoder.Create(new Uri(FileName), BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default);
                        var getFrames = gif.Frames;
                        BitmapFrame[] frames = getFrames.ToArray();
                        await Task.Run(() =>
                        {


                            while (ab < getFrames.Count())
                            {
                                Thread.Sleep(speed);
try
{
                                Dispatcher.Invoke(() =>
                                {
                                    gifImage.Source = frames[ab];
                                });
                                if (ab == getFrames.Count - 1&&_Repeat)
                                {
                                    ab = 0;

                                }
                                ab++;
            }
 catch
{
}

                            }
                        });
                    }

or

     public async Task GIF_Animation_Pro(Stream stream, int speed,bool _Repeat)
            {
 int ab = 0;   
                var gif = GifBitmapDecoder.Create(stream , BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default);
                var getFrames = gif.Frames;
                BitmapFrame[] frames = getFrames.ToArray();
                await Task.Run(() =>
                {


                    while (ab < getFrames.Count())
                    {
                        Thread.Sleep(speed);
    try
    {


                     Dispatcher.Invoke(() =>
                        {
                            gifImage.Source = frames[ab];
                        });
                        if (ab == getFrames.Count - 1&&_Repeat)
                        {
                            ab = 0;

                        }
                        ab++;
    }
     catch{} 



                    }
                });
            }