我应该使用什么控件类型-图像,MediaElement等?


当前回答

在WPF中等待动画的替代方法是:

 <ProgressBar Height="20" Width="100" IsIndeterminate="True"/>

它将显示一个动画进度条。

其他回答

之前,我也遇到过类似的问题,我需要在你的项目中播放gif文件。我有两个选择:

使用WinForms中的PictureBox 使用第三方库,如codeplex.com的WPFAnimatedGif。

带有PictureBox的版本不适合我,而且项目不能为它使用外部库。所以我通过ImageAnimator的帮助,通过Bitmap为自己制作了它。因为,标准的BitmapImage不支持gif文件的回放。

完整的例子:

XAML

<Window x:Class="PlayGifHelp.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" Loaded="MainWindow_Loaded">

    <Grid>
        <Image x:Name="SampleImage" />
    </Grid>
</Window>

后面的代码

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    Bitmap _bitmap;
    BitmapSource _source;

    private BitmapSource GetSource()
    {
        if (_bitmap == null)
        {
            string path = Directory.GetCurrentDirectory();

            // Check the path to the .gif file
            _bitmap = new Bitmap(path + @"\anim.gif");
        }

        IntPtr handle = IntPtr.Zero;
        handle = _bitmap.GetHbitmap();

        return Imaging.CreateBitmapSourceFromHBitmap(handle, IntPtr.Zero, Int32Rect.Empty, BitmapSizeOptions.FromEmptyOptions());
    }

    private void MainWindow_Loaded(object sender, RoutedEventArgs e)
    {
        _source = GetSource();
        SampleImage.Source = _source;
        ImageAnimator.Animate(_bitmap, OnFrameChanged);
    }

    private void FrameUpdatedCallback()
    {
        ImageAnimator.UpdateFrames();

        if (_source != null)
        {
            _source.Freeze();
        }

        _source = GetSource();

        SampleImage.Source = _source;
        InvalidateVisual();
    }

    private void OnFrameChanged(object sender, EventArgs e)
    {
        Dispatcher.BeginInvoke(DispatcherPriority.Normal, new Action(FrameUpdatedCallback));
    }
}

位图不支持URI指令,所以我从当前目录加载。gif文件。

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);

你可以尝试使用web浏览器UI控件,并设置html字符串为html图像标签…

XML:

    <WebBrowser Name="webBrowser1"/>

c#: f

    webBrowser1.NavigateToString(        
      @"<img src=""arrow-24.png""/>"
    );

上面的方法我都试过了,但每个方法都有自己的不足,感谢大家,我想出了自己的GifImage:

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Windows.Controls;
    using System.Windows;
    using System.Windows.Media.Imaging;
    using System.IO;
    using System.Windows.Threading;

    namespace IEXM.Components
    {
    public class GifImage : Image
    {
            #region gif Source, such as "/IEXM;component/Images/Expression/f020.gif"
            public string GifSource
            {
                    get { return (string)GetValue(GifSourceProperty); }
                    set { SetValue(GifSourceProperty, value); }
            }

            public static readonly DependencyProperty GifSourceProperty =
                    DependencyProperty.Register("GifSource", typeof(string),
                    typeof(GifImage), new UIPropertyMetadata(null, GifSourcePropertyChanged));

            private static void GifSourcePropertyChanged(DependencyObject sender,
                    DependencyPropertyChangedEventArgs e)
            {
                    (sender as GifImage).Initialize();
            }
            #endregion

            #region control the animate
            /// <summary>
            /// Defines whether the animation starts on it's own
            /// </summary>
            public bool IsAutoStart
            {
                    get { return (bool)GetValue(AutoStartProperty); }
                    set { SetValue(AutoStartProperty, value); }
            }

            public static readonly DependencyProperty AutoStartProperty =
                    DependencyProperty.Register("IsAutoStart", typeof(bool),
                    typeof(GifImage), new UIPropertyMetadata(false, AutoStartPropertyChanged));

            private static void AutoStartPropertyChanged(DependencyObject sender,
                    DependencyPropertyChangedEventArgs e)
            {
                    if ((bool)e.NewValue)
                            (sender as GifImage).StartAnimation();
                    else
                            (sender as GifImage).StopAnimation();
            }
            #endregion

            private bool _isInitialized = false;
            private System.Drawing.Bitmap _bitmap;
            private BitmapSource _source;

            [System.Runtime.InteropServices.DllImport("gdi32.dll")]
            public static extern bool DeleteObject(IntPtr hObject);

            private BitmapSource GetSource()
            {
                    if (_bitmap == null)
                    {
                            _bitmap = new System.Drawing.Bitmap(Application.GetResourceStream(
                                     new Uri(GifSource, UriKind.RelativeOrAbsolute)).Stream);
                    }

                    IntPtr handle = IntPtr.Zero;
                    handle = _bitmap.GetHbitmap();

                    BitmapSource bs = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(
                            handle, IntPtr.Zero, Int32Rect.Empty, BitmapSizeOptions.FromEmptyOptions());
                    DeleteObject(handle);
                    return bs;
            }

            private void Initialize()
            {
            //        Console.WriteLine("Init: " + GifSource);
                    if (GifSource != null)
                            Source = GetSource();
                    _isInitialized = true;
            }

            private void FrameUpdatedCallback()
            {
                    System.Drawing.ImageAnimator.UpdateFrames();

                    if (_source != null)
                    {
                            _source.Freeze();
                    }

               _source = GetSource();

              //  Console.WriteLine("Working: " + GifSource);

                    Source = _source;
                    InvalidateVisual();
            }

            private void OnFrameChanged(object sender, EventArgs e)
            {
                    Dispatcher.BeginInvoke(DispatcherPriority.Normal, new Action(FrameUpdatedCallback));
            }

            /// <summary>
            /// Starts the animation
            /// </summary>
            public void StartAnimation()
            {
                    if (!_isInitialized)
                            this.Initialize();


             //   Console.WriteLine("Start: " + GifSource);

                    System.Drawing.ImageAnimator.Animate(_bitmap, OnFrameChanged);
            }

            /// <summary>
            /// Stops the animation
            /// </summary>
            public void StopAnimation()
            {
                    _isInitialized = false;
                    if (_bitmap != null)
                    {
                            System.Drawing.ImageAnimator.StopAnimate(_bitmap, OnFrameChanged);
                            _bitmap.Dispose();
                            _bitmap = null;
                    }
                    _source = null;
                    Initialize();
                    GC.Collect();
                    GC.WaitForFullGCComplete();

             //   Console.WriteLine("Stop: " + GifSource);
            }

            public void Dispose()
            {
                    _isInitialized = false;
                    if (_bitmap != null)
                    {
                            System.Drawing.ImageAnimator.StopAnimate(_bitmap, OnFrameChanged);
                            _bitmap.Dispose();
                            _bitmap = null;
                    }
                    _source = null;
                    GC.Collect();
                    GC.WaitForFullGCComplete();
               // Console.WriteLine("Dispose: " + GifSource);
            }
    }
}

用法:

<localComponents:GifImage x:Name="gifImage" IsAutoStart="True" GifSource="{Binding Path=value}" />

因为它不会导致内存泄漏,它动画gif图像自己的时间线,你可以尝试一下。

GifImage.Initialize()方法的小改进,该方法从GIF元数据中读取适当的帧定时。

    private void Initialize()
    {
        _gifDecoder = new GifBitmapDecoder(new Uri("pack://application:,,," + this.GifSource), BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default);

        int duration=0;
        _animation = new Int32AnimationUsingKeyFrames();
        _animation.KeyFrames.Add(new DiscreteInt32KeyFrame(0, KeyTime.FromTimeSpan(new TimeSpan(0))));
        foreach (BitmapFrame frame in _gifDecoder.Frames)
        {
            BitmapMetadata btmd = (BitmapMetadata)frame.Metadata;
            duration += (ushort)btmd.GetQuery("/grctlext/Delay");
            _animation.KeyFrames.Add(new DiscreteInt32KeyFrame(_gifDecoder.Frames.IndexOf(frame)+1, KeyTime.FromTimeSpan(new TimeSpan(duration*100000))));
        }            
         _animation.RepeatBehavior = RepeatBehavior.Forever;
        this.Source = _gifDecoder.Frames[0];            
        _isInitialized = true;
    }