如何获得此WPF .gif以便在更新时播放?
|
题:
为什么用
GifSourcePropertyChanged
加载我的.gif
却不能播放?
大约.gif
装载:
目前我已经使用U.IsValidURL()
来防止new Uri
投掷Exception
。这是因为我需要ѭ6才能加载应用程序,然后再从ѭ7进行更新。一切正常,直到调用GifSourcePropertyChanged
,然后更新local:GifImage
,但the0ѭ不播放(我相信它会随着MediaElement
并行加载而载入,而local:GifImage
会变黑,假设where0ѭ要加载)。如果我从一开始就对样本Uri
进行硬编码,则local:GifImage
会加载并正常播放。
XAML示例:
<local:GifImage
GifSource=\"{
Binding Path=myGifImage,
UpdateSourceTrigger=PropertyChanged,
Mode=OneWay}\"
AutoStart=\"True\"/>
示例ViewModel:
public class ViewModel: INotifyPropertyChanged
{
private string _myGifImage;
public string myGifImage
{
get { return this._myGifImage; }
set
{
this._myGifImage = value;
this.OnPropertyChanged(\"myGifImage\");
}
}
}
示例GifImage类:
public class GifImage : Image
{
#region Memmbers
private GifBitmapDecoder _gifDecoder;
private Int32Animation _animation;
private bool _isInitialized;
#endregion Memmbers
#region Properties
private int FrameIndex
{
get { return (int)GetValue(FrameIndexProperty); }
set { SetValue(FrameIndexProperty, value); }
}
private static readonly DependencyProperty FrameIndexProperty =
DependencyProperty.Register(\"FrameIndex\", typeof(int), typeof(GifImage), new FrameworkPropertyMetadata(0, new PropertyChangedCallback(ChangingFrameIndex)));
private static void ChangingFrameIndex(DependencyObject obj, DependencyPropertyChangedEventArgs ev)
{
GifImage image = obj as GifImage;
image.Source = image._gifDecoder.Frames[(int)ev.NewValue];
}
/// <summary>
/// Defines whether the animation starts on it\'s own
/// </summary>
public bool AutoStart
{
get { return (bool)GetValue(AutoStartProperty); }
set { SetValue(AutoStartProperty, value); }
}
public static readonly DependencyProperty AutoStartProperty =
DependencyProperty.Register(\"AutoStart\", typeof(bool), typeof(GifImage), new UIPropertyMetadata(false, AutoStartPropertyChanged));
private static void AutoStartPropertyChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
if ((bool)e.NewValue)
(sender as GifImage).StartAnimation();
}
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(string.Empty, GifSourcePropertyChanged));
private static void GifSourcePropertyChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
// CARLO 20100622: Reinitialize animation everytime image is changed
(sender as GifImage).Initialize();
}
#endregion Properties
#region Private Instance Methods
private void Initialize()
{
if (U.IsValidURL(this.GifSource, UriKind.Absolute))
{
_gifDecoder = new GifBitmapDecoder(
new Uri(this.GifSource),
BitmapCreateOptions.PreservePixelFormat,
BitmapCacheOption.Default);
_animation = new Int32Animation(0, _gifDecoder.Frames.Count - 1, new Duration(new TimeSpan(0, 0, 0, _gifDecoder.Frames.Count / 10, (int)((_gifDecoder.Frames.Count / 10.0 - _gifDecoder.Frames.Count / 10) * 1000))));
_animation.RepeatBehavior = RepeatBehavior.Forever;
this.Source = _gifDecoder.Frames[0];
_isInitialized = true;
}
}
#endregion Private Instance Methods
#region Public Instance Methods
/// <summary>
/// Shows and starts the gif animation
/// </summary>
public void Show()
{
this.Visibility = Visibility.Visible;
this.StartAnimation();
}
/// <summary>
/// Hides and stops the gif animation
/// </summary>
public void Hide()
{
this.Visibility = Visibility.Collapsed;
this.StopAnimation();
}
/// <summary>
/// Starts the animation
/// </summary>
public void StartAnimation()
{
if (!_isInitialized)
this.Initialize();
BeginAnimation(FrameIndexProperty, _animation);
}
/// <summary>
/// Stops the animation
/// </summary>
public void StopAnimation()
{
BeginAnimation(FrameIndexProperty, null);
}
#endregion Public Instance Methods
}
我从某处的某个地方得到了6英镑(我不记得哪个问题,在20英镑和21英镑上有几个问题)。 GifImage
是唯一没有很多错误的类(至少对我而言)。
没有找到相关结果
已邀请:
1 个回复
梦砍废么