具有自定义样式的TextBox未激发GotFocus

Question

我遇到了一个对一些人来说可能很简单的问题，尽管我尽了最大努力，但我还是无法"解决"这个问题：

我有一个TextBox的自定义样式，在"公共"程序集中定义；此样式覆盖默认样式，因此每次有人使用TextBox时都会使用此样式。问题是，当应用样式时，GotFocus、IsKeyboardFocusWithinChanged和PreviewGotKeyboard福克斯事件不再被激发。我已经验证了只有当应用此样式时才会发生这种情况（如果我注释掉它并运行应用程序，则事件会正确触发）。

所以我的问题是，有人经历过类似的事情吗？如果是的话，有人知道这个问题的解决方案吗？

样式如下（静态资源一个简单的SolidColorBrushes）：

<Style TargetType="{x:Type TextBox}" x:Key="{x:Type TextBox}" BasedOn="{StaticResource {x:Type TextBox}}">
    <Setter Property="FocusVisualStyle" Value="{x:Null}" />
    <Setter Property="OverridesDefaultStyle" Value="True" />
    <Setter Property="BorderBrush" Value="{StaticResource BrushBorder}"/>
    <Setter Property="ContextMenu" Value="{StaticResource TextBoxContextMenu}" />
    <Setter Property="Foreground" Value="{StaticResource BrushForeground}" />
    <Setter Property="SelectionBrush" Value="{StaticResource BrushHighlight}" />
    <Setter Property="Background" Value="{StaticResource BrushBackground}"/>
    <Setter Property="KeyboardNavigation.TabNavigation" Value="None"/>
    <Setter Property="SnapsToDevicePixels" Value="True"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type TextBox}">
                <Border BorderThickness="1" x:Name="Border" BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}">
                    <ScrollViewer x:Name="PART_ContentHost"
                                  Margin="0" />
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
    <Style.Triggers>
        <Trigger Property="IsKeyboardFocusWithin" Value="True">
            <Setter Property="Background" Value="{StaticResource BrushLightBg}" />
        </Trigger>
        <Trigger Property="IsMouseOver" Value="True">
            <Setter Property="Background" Value="{StaticResource BrushMouseoverBackground}" />
        </Trigger>
    </Style.Triggers>
</Style>

Answer 1

嗨，我在这里工作得很好，我不得不添加一些你错过的颜色，这会让你的眼睛流血，对不起，但我有点着急：）

<!-- nice colors you were missing them ;) -->
<SolidColorBrush x:Key="BrushBorder" Color="Blue"/>
<SolidColorBrush x:Key="TextBoxContextMenu" Color="DeepPink"/>
<SolidColorBrush x:Key="BrushForeground" Color="Red"/>        
<SolidColorBrush x:Key="BrushHighlight" Color="Aqua"/>
<SolidColorBrush x:Key="BrushBackground" Color="DarkBlue"/>
<SolidColorBrush x:Key="BrushLightBg" Color="LightSeaGreen"/>
<SolidColorBrush x:Key="BrushMouseoverBackground" Color="Yellow"/>
<Style TargetType="{x:Type TextBox}" x:Key="TextBoxStyleMessed" BasedOn="{StaticResource {x:Type TextBox}}" >
    <Setter Property="FocusVisualStyle" Value="{x:Null}" />
    <Setter Property="OverridesDefaultStyle" Value="True" />
    <Setter Property="BorderBrush" Value="{StaticResource BrushBorder}"/>
    <!--<Setter Property="ContextMenu" Value="{StaticResource TextBoxContextMenu}" />-->
    <Setter Property="Foreground" Value="{StaticResource BrushForeground}" />
    <Setter Property="SelectionBrush" Value="{StaticResource BrushHighlight}" />
    <Setter Property="Background" Value="{StaticResource BrushBackground}"/>
    <Setter Property="KeyboardNavigation.TabNavigation" Value="None"/>
    <Setter Property="SnapsToDevicePixels" Value="True"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type TextBox}">
                <Border BorderThickness="1" x:Name="Border" BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}">
                    <ScrollViewer x:Name="PART_ContentHost" Margin="0" />
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
    <Style.Triggers>
        <Trigger Property="IsKeyboardFocusWithin" Value="True">
            <Setter Property="Background" Value="{StaticResource BrushLightBg}" />
        </Trigger>
        <Trigger Property="IsMouseOver" Value="True">
            <Setter Property="Background" Value="{StaticResource BrushMouseoverBackground}" />
        </Trigger>
    </Style.Triggers>
</Style>
.....
<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>
    <TextBox Text="Hello!" HorizontalAlignment="Center" VerticalAlignment="Center" Style="{DynamicResource TextBoxStyleMessed}" 
             x:Name="HateThisNonMVVMStuff"/>
    <Button Grid.Row="1">Hodwy</Button>
</Grid>

不得不偷工减料，但令人讨厌的代码隐藏：

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        Loaded += MainWindow_Loaded;
    }
    void MainWindow_Loaded(object sender, RoutedEventArgs e)
    {
        HateThisNonMVVMStuff.PreviewLostKeyboardFocus += HateThisNonMVVMStuff_PreviewLostKeyboardFocus;
        HateThisNonMVVMStuff.LostFocus += UIElement_OnLostFocus;
        HateThisNonMVVMStuff.GotFocus += UIElement_OnGotFocus;
    }
    void HateThisNonMVVMStuff_PreviewLostKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e)
    {
        System.Diagnostics.Trace.WriteLine("PrevLostFocus!");
    }
    private void UIElement_OnGotFocus(object sender, RoutedEventArgs e)
    {
        System.Diagnostics.Trace.WriteLine("Hei! Gained focus");
    }
    private void UIElement_OnLostFocus(object sender, RoutedEventArgs e)
    {
        System.Diagnostics.Trace.WriteLine("Hei! Lost focus");        
    }
}

事件激发了你的风格，我把它当作一种风格只用于这个盒子。我在你的上下文菜单上得到了一个例外，它不会有我讨厌的颜色，但嘿，谁会呢！：D

希望有帮助，

干杯，

Stian