WPF尝试动画绑定前景时出现异常。

huangapple
go评论106阅读模式
英文:

WPF Exception when try animating binding foreground

问题

我有这个控件...:

  1. <iconPack:PackIconAlvo
  2.     Width="{StaticResource iconSize}"
  3.     Height="{StaticResource iconSize}"
  4.     HorizontalAlignment="Center"
  5.     Foreground="{Binding IsMonitoringButtonActive, Converter={StaticResource IsSelectedToColorConverter}}"
  6.     Kind="Monitoring"
  7.     Style="{StaticResource AlarmAnimation}" />

...使用了这个转换器...:

  1. public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
  2. {
  3.     return (bool)value ? new SolidColorBrush(Color.FromRgb(0, 255, 161)) : new SolidColorBrush(Color.FromRgb(131, 131, 131));
  4. }

...和这个动画样式:

  1. <Style x:Key="AlarmAnimation">
  2.     <Style.Triggers>
  3.         <DataTrigger Binding="{Binding IsAlarmForMonitoringButton}" Value="True">
  4.             <DataTrigger.EnterActions>
  5.                 <BeginStoryboard>
  6.                     <Storyboard>
  7.                         <ColorAnimation
  8.                             AutoReverse="True"
  9.                             RepeatBehavior="Forever"
  10.                             Storyboard.TargetProperty="Foreground.(SolidColorBrush.Color)"
  11.                             From="Gray"
  12.                             To="Red"
  13.                             Duration="0:0:0.5" />
  14.                     </Storyboard>
  15.                 </BeginStoryboard>
  16.             </DataTrigger.EnterActions>
  17.         </DataTrigger>
  18.     </Style.Triggers>
  19. </Style>

当我启动动画（IsAlarmForMonitoringButton == true）并且 IsMonitoringButtonActive == false 时，我遇到了错误:

无法在不可变对象实例上执行动画 'Foreground.(0)'。

我无法解决这个错误。在这个应用程序中，前景是可变的很重要，当IsAlarmForMonitoringButton==true时它也很重要。

如何处理这个问题？

英文:

I have this control…:

  1. &lt;iconPack:PackIconAlvo
  2. 	Width=&quot;{StaticResource iconSize}&quot;
  3. 	Height=&quot;{StaticResource iconSize}&quot;
  4. 	HorizontalAlignment=&quot;Center&quot;
  5. 	Foreground=&quot;{Binding IsMonitoringButtonActive, Converter={StaticResource IsSelectedToColorConverter}}&quot;
  6. 	Kind=&quot;Monitoring&quot;
  7. 	Style=&quot;{StaticResource AlarmAnimation}&quot; /&gt;

…with this converter…:

  1. public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
  2. {
  3. 	return (bool)value ? new SolidColorBrush(Color.FromRgb(0, 255, 161)) : new SolidColorBrush(Color.FromRgb(131, 131, 131));
  4. }

…and this animation style:

  1. &lt;Style x:Key=&quot;AlarmAnimation&quot;&gt;
  2. 	&lt;Style.Triggers&gt;
  3. 		&lt;DataTrigger Binding=&quot;{Binding IsAlarmForMonitoringButton}&quot; Value=&quot;True&quot;&gt;
  4. 			&lt;DataTrigger.EnterActions&gt;
  5. 				&lt;BeginStoryboard&gt;
  6. 					&lt;Storyboard&gt;
  7. 						&lt;ColorAnimation
  8. 							AutoReverse=&quot;True&quot;
  9. 							RepeatBehavior=&quot;Forever&quot;
  10. 							Storyboard.TargetProperty=&quot;Foreground.(SolidColorBrush.Color)&quot;
  11. 							From=&quot;Gray&quot;
  12. 							To=&quot;Red&quot;
  13. 							Duration=&quot;0:0:0.5&quot; /&gt;
  14. 					&lt;/Storyboard&gt;
  15. 				&lt;/BeginStoryboard&gt;
  16. 			&lt;/DataTrigger.EnterActions&gt;
  17. 		&lt;/DataTrigger&gt;
  18. 	&lt;/Style.Triggers&gt;
  19. &lt;/Style&gt;

When I start animation (IsAlarmForMonitoringButton == true) and IsMonitoringButtonActive == false, then I have error:

> Cannot animate 'Foreground.(0)' on an immutable object instance.

I can't deal with this error. It is important in this application that the foreground is variable, it is also important that it is animated when IsAlarmForMonitoringButton==true.

How can I handle this problem?

答案1

得分: 2

使用Style而不是使用绑定表达式和转换器来设置Foreground属性，例如：

  1. <iconPack:PackIconAlvo
  2.     Width="{StaticResource iconSize}"
  3.     Height="{StaticResource iconSize}"
  4.     HorizontalAlignment="Center"
  5.     Kind="Monitoring">
  6.     <iconPack:PackIconAlvo.Style>
  7.         <Style TargetType="iconPack:PackIconAlvo">
  8.             <Setter Property="Foreground" Value="Yellow" />
  9.             <Style.Triggers>
  10.                 <DataTrigger Binding="{Binding IsMonitoringButtonActive}" Value="True">
  11.                     <Setter Property="Foreground" Value="Red" />
  12.                 </DataTrigger>
  13.                 <DataTrigger Binding="{Binding IsAlarmForMonitoringButton}" Value="True">
  14.                     <DataTrigger.EnterActions>
  15.                         <BeginStoryboard>
  16.                             <Storyboard>
  17.                                 <ColorAnimation
  18.                                     AutoReverse="True"
  19.                                     RepeatBehavior="Forever"
  20.                                     Storyboard.TargetProperty="Foreground.(SolidColorBrush.Color)"
  21.                                     From="Gray"
  22.                                     To="Red"
  23.                                     Duration="0:0:0.5" />
  24.                             </Storyboard>
  25.                         </BeginStoryboard>
  26.                     </DataTrigger.EnterActions>
  27.                 </DataTrigger>
  28.             </Style.Triggers>
  29.         </Style>
  30.     </iconPack:PackIconAlvo.Style>
  31. </iconPack:PackIconAlvo>

另一种选项是以编程方式应用动画。

英文:

Set the Foreground property using a Style instead of using a binding expression and a converter, e.g.:

  1. &lt;iconPack:PackIconAlvo
  2.         Width=&quot;{StaticResource iconSize}&quot;
  3.         Height=&quot;{StaticResource iconSize}&quot;
  4.         HorizontalAlignment=&quot;Center&quot;
  5.         Kind=&quot;Monitoring&quot;&gt;
  6.     &lt;iconPack:PackIconAlvo.Style&gt;
  7.         &lt;Style TargetType=&quot;iconPack:PackIconAlvo&quot;&gt;
  8.             &lt;Setter Property=&quot;Foreground&quot; Value=&quot;Yellow&quot; /&gt;
  9.             &lt;Style.Triggers&gt;
  10.                 &lt;DataTrigger Binding=&quot;{Binding IsMonitoringButtonActive}&quot; Value=&quot;True&quot;&gt;
  11.                     &lt;Setter Property=&quot;Foreground&quot; Value=&quot;Red&quot; /&gt;
  12.                 &lt;/DataTrigger&gt;
  13.                 &lt;DataTrigger Binding=&quot;{Binding IsAlarmForMonitoringButton}&quot; Value=&quot;True&quot;&gt;
  14.                     &lt;DataTrigger.EnterActions&gt;
  15.                         &lt;BeginStoryboard&gt;
  16.                             &lt;Storyboard&gt;
  17.                                 &lt;ColorAnimation
  18.                                     AutoReverse=&quot;True&quot;                                
  19.                                     RepeatBehavior=&quot;Forever&quot;
  20.                                     Storyboard.TargetProperty=&quot;Foreground.(SolidColorBrush.Color)&quot;
  21.                                     From=&quot;Gray&quot;
  22.                                     To=&quot;Red&quot;
  23.                                     Duration=&quot;0:0:0.5&quot; /&gt;
  24.                             &lt;/Storyboard&gt;
  25.                         &lt;/BeginStoryboard&gt;
  26.                     &lt;/DataTrigger.EnterActions&gt;
  27.                 &lt;/DataTrigger&gt;
  28.             &lt;/Style.Triggers&gt;
  29.         &lt;/Style&gt;
  30.     &lt;/iconPack:PackIconAlvo.Style&gt;
  31. &lt;/iconPack:PackIconAlvo&gt;

The other option is to apply the animation programmatically.

huangapple
  • 本文由 发表于 2023年4月4日 16:16:38
  • 转载请务必保留本文链接：https://go.coder-hub.com/75927012.html
  • c#
  • wpf
匿名

发表评论

匿名网友

:?: :razz: :sad: :evil: :!: :smile: :oops: :grin: :eek: :shock: :???: :cool: :lol: :mad: :twisted: :roll: :wink: :idea: :arrow: :neutral: :cry: :mrgreen:

确定