wpf - 在xaml中创建自定义VisualState并在CodeBehind中手动进行设置

Question

我有一个TabItem样式，具有VisualStates。

<VisualState x:Name="MouseOver"> 
<!-- Tab turns bronze when mouseover -->
</VisualState>

现在，我想拥有一个自定义的视觉状态，并在代码隐藏中手动设置该状态，而不是依赖于MouseOver事件。

<VisualState x:Name="CustomVisualState">
<!-- this will be a storyboard to cause flashing -->
</VisualState> 

然后，我需要在CodeBehind中进行设置。

MyTabItem.VisualState = CustomVisualState.  //something like this

Answer 1

你有没有尝试过VisualStateManager.GoToState接受Control，带有自定义状态名称的字符串和用于转换的bool标志。
来自msdn的示例用法

private void UpdateStates(bool useTransitions)
{
    if (Value >= 0)
    {
        VisualStateManager.GoToState(this, "Positive", useTransitions);
    }
    else
    {
        VisualStateManager.GoToState(this, "Negative", useTransitions);
    }

    if (IsFocused)
    {
        VisualStateManager.GoToState(this, "Focused", useTransitions);
    }
    else
    {
        VisualStateManager.GoToState(this, "Unfocused", useTransitions);
    }
}

here的示例用法稍微复杂一些

Given this xaml

      <Grid x:Name="LayoutRoot"  Background="LightBlue">
          <VisualStateManager.VisualStateGroups>
              <VisualStateGroup x:Name="SG1">
                  <VisualStateGroup.Transitions>
                      <VisualTransition GeneratedDuration="00:00:01">
                          <VisualTransition.GeneratedEasingFunction>
                              <ElasticEase EasingMode="EaseOut"/>
                          </VisualTransition.GeneratedEasingFunction>
                      </VisualTransition>
                  </VisualStateGroup.Transitions>
                  <VisualState x:Name="SG1Normal"/>
                  <VisualState x:Name="SG1EllipseRight" >
                      <Storyboard>
                            <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="ellipse" Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[3].(TranslateTransform.X)">
                              <EasingDoubleKeyFrame KeyTime="00:00:00" Value="320"/>
                          </DoubleAnimationUsingKeyFrames>
                      </Storyboard>
                  </VisualState>
              </VisualStateGroup>
          </VisualStateManager.VisualStateGroups>
          <Ellipse x:Name="ellipse" Fill="Red" Stroke="Black" 
                   Height="116" HorizontalAlignment="Left" Margin="50,98,0,0" 
                   VerticalAlignment="Top" Width="235" RenderTransformOrigin="0.5,0.5" >
              <Ellipse.RenderTransform>
                  <TransformGroup>
                      <ScaleTransform/>
                      <SkewTransform/>
                      <RotateTransform/>
                      <TranslateTransform/>
                  </TransformGroup>
              </Ellipse.RenderTransform>
          </Ellipse>
      </Grid>

Changing state can be done like so.

 VisualStateManager.GoToState(this, SG1EllipseRight.Name, true);

Or alternatively

VisualStateManager.GoToState(control, "SG1EllipseRight", true);