Question

我使用Blend for Visual Studio创建了最简单的WPF应用程序。

我为单个文本框创建了最简单的可视状态组：

我的问题是我无法使用此代码动态GoToState：

public MainWindow()
{
    InitializeComponent();
    textBox.MouseEnter+=new System.Windows.Input.MouseEventHandler(textBox_MouseEnter);
}
private void textBox_MouseEnter(object sender, System.Windows.Input.MouseEventArgs e)
{
    // This will be an empty list
    var states = VisualStateManager.GetVisualStateGroups(textBox);
    // This will be false
    bool thisReturnsFalse =   VisualStateManager.GoToState(textBox, "VisualState1", true);
}

这是我的XAML：

<VisualStateManager.VisualStateGroups>
    <VisualStateGroup x:Name="VisualStateGroup">
        <VisualState x:Name="VisualState">
            <Storyboard>
                <ColorAnimationUsingKeyFrames Storyboard.TargetProperty="(Panel.Background).(SolidColorBrush.Color)" Storyboard.TargetName="textBox">
                    <EasingColorKeyFrame KeyTime="0" Value="#FFE40404"/>
                </ColorAnimationUsingKeyFrames>
            </Storyboard>
        </VisualState>
        <VisualState x:Name="VisualState1">
            <Storyboard>
                <ColorAnimationUsingKeyFrames Storyboard.TargetProperty="(Panel.Background).(SolidColorBrush.Color)" Storyboard.TargetName="textBox">
                    <EasingColorKeyFrame KeyTime="0" Value="#FF23FF00"/>
                </ColorAnimationUsingKeyFrames>
            </Storyboard>
        </VisualState>
    </VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<TextBox x:Name="textBox" HorizontalAlignment="Left" Height="23" TextWrapping="Wrap" Text="TextBox" VerticalAlignment="Top" Width="120">
    <i:Interaction.Triggers>
        <i:EventTrigger EventName="KeyUp">
            <ei:GoToStateAction StateName="VisualState1"/>
        </i:EventTrigger>
        <i:EventTrigger EventName="KeyDown">
            <ei:GoToStateAction StateName="VisualState"/>
        </i:EventTrigger>
    </i:Interaction.Triggers>
</TextBox>

Answer 1

您的VisualStateGroups未在TextBox中定义，因此呼叫

var states = VisualStateManager.GetVisualStateGroups(textBox);

不会返回您的期望。如果您想获得已定义的状态，请传递包含FrameworkElement的{{1}}（我假设此处为VisualStateGroups）：

Window

同样应该用于调用var states = VisualStateManager.GetVisualStateGroups(this);：

VisualStateManager.GoToState

我不能在WPF中动态GoToState。怎么了？

1 个答案: