Question

我想在按下和释放期间更改按钮的背景。我在c＃通用Windows平台上编码。我正在尝试以下但失败了。

 private void pay_LostFocus(object sender, RoutedEventArgs e)
    {
        pay.Background = new SolidColorBrush(Windows.UI.Colors.Pink);
    }

    private void one_FocusEngaged(Control sender, FocusEngagedEventArgs args)
    {
        one.Background = new SolidColorBrush(Windows.UI.Colors.White);
    }

Answer 1

只需修改按钮的样式，尤其是 Pressed VisualState。样品：

<Style x:Key="MyButtonStyle" TargetType="Button">
    <Setter Property="Background" Value="{ThemeResource ButtonBackground}"/>
    <Setter Property="Foreground" Value="{ThemeResource ButtonForeground}"/>
    <Setter Property="BorderBrush" Value="{ThemeResource ButtonBorderBrush}"/>
    <Setter Property="BorderThickness" Value="{ThemeResource ButtonBorderThemeThickness}"/>
    <Setter Property="Padding" Value="8,4,8,4"/>
    <Setter Property="HorizontalAlignment" Value="Left"/>
    <Setter Property="VerticalAlignment" Value="Center"/>
    <Setter Property="FontFamily" Value="{ThemeResource ContentControlThemeFontFamily}"/>
    <Setter Property="FontWeight" Value="Normal"/>
    <Setter Property="FontSize" Value="{ThemeResource ControlContentThemeFontSize}"/>
    <Setter Property="UseSystemFocusVisuals" Value="True"/>
    <Setter Property="FocusVisualMargin" Value="-3"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="Button">
                <Grid x:Name="RootGrid" Background="{TemplateBinding Background}">
                    <VisualStateManager.VisualStateGroups>
                        <VisualStateGroup x:Name="CommonStates">
                            <VisualState x:Name="Normal">
                                <Storyboard>
                                    <PointerUpThemeAnimation Storyboard.TargetName="RootGrid"/>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="PointerOver">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="RootGrid">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonBackgroundPointerOver}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="ContentPresenter">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonBorderBrushPointerOver}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonForegroundPointerOver}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <PointerUpThemeAnimation Storyboard.TargetName="RootGrid"/>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Pressed">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="RootGrid">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="White"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="ContentPresenter">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonBorderBrushPressed}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonForegroundPressed}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <PointerDownThemeAnimation Storyboard.TargetName="RootGrid"/>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Disabled">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="RootGrid">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonBackgroundDisabled}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="ContentPresenter">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonBorderBrushDisabled}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonForegroundDisabled}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>
                    <ContentPresenter x:Name="ContentPresenter" AutomationProperties.AccessibilityView="Raw" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" ContentTemplate="{TemplateBinding ContentTemplate}" ContentTransitions="{TemplateBinding ContentTransitions}" Content="{TemplateBinding Content}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" Padding="{TemplateBinding Padding}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"/>
                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

然后使用它：

<Button Content="Something" Style="{StaticResource MyButtonStyle}" Padding="20" Background="Pink"/>

Answer 2

您可以使用指针事件来执行此操作，但您必须通过AddHandler方法手动添加处理程序，因为您还需要能够处理以前处理的指针事件以确保用户界面保持一致。

您可以使用此代码：

MyButton.AddHandler(
  UIElement.PointerEnteredEvent, // The target event
  new PointerEventHandler((s, e) => 
  {
      // Handle your background here
  }), 
  true); // Include previously handled events

以下是您需要使用的事件：UIElement.PointerEnteredEvent，UIElement.PointerExitedEvent，UIElement.PointerCaptureLostEvent，UIElement.PointerCanceledEvent，UIElement.PointerReleasedEvent。

您需要根据源事件调整按钮的背景，因为当用户开始按下按钮时会触发其中一些方法，而当按钮被释放时会激活其他方法。

修改：这是添加按钮释放时处理程序的示例：

foreach (RoutedEvent target in new[] { UIElement.PointerExitedEvent, UIElement.PointerCaptureLostEvent,
                                        UIElement.PointerCanceledEvent, UIElement.PointerReleasedEvent })
{
    MyButton.AddHandler(target, new PointerRoutedEventArgs((s, e) => 
    {
        MyButton.Background = new SolidColorBrush(Colors.Red);
    }), true);
}

使用另一个画笔（当按下按钮时）对PointerPressedEvent执行相同操作，并且您应该全部设置。

如何在按下和释放之间的持续时间内更改按钮的背景？

2 个答案: