Question

我是XAML的新手，WPF（第一个项目;-)）。我的目标是应用App.xaml中声明的自定义组合框。但是，如果我然后在MainWindow.xaml中使用组合框，我不知道如何将单击处理程序附加到组合框中锚定的togglebutton。如果我将一个Click属性添加到App.xaml中的ToggleButton，如果我在App.cs中实现处理程序，我只能成功捕获该事件。

到目前为止我尝试过：

请参阅MainWindow.xaml中ComboBox元素内部的ToggleButton（我对xaml在这一点上的工作方式没有很好的直觉......），这会导致ToggleButton上的一些不良视觉效果，仅此而已。
```
<ComboBox x:Name="someComboBox" 
          Height="23"
          Margin="122,35,1.8,0"
          VerticalAlignment="Top">

         <ToggleButton Click="toggleHandler_Click" />
```

从MainWindow.cs中获取ToggleButton然后附加处理程序，尽管前者采用下面的方法结果为null

    ToggleButton tBtn = ((ComboBox)someComboBox).FindName("MyToggleButton") as ToggleButton; // null

    ToggleButton tBtn = LogicalTreeHelper.FindLogicalNode(someComboBox, "MyToggleButton"); // null

这是App.xaml中的自定义组合框，我采用了

        <Style TargetType="ComboBox">
            <Setter Property="Validation.ErrorTemplate" Value="{x:Null}" />
            <Setter Property="VerticalAlignment" Value="Center" />
            <Setter Property="OverridesDefaultStyle" Value="true" />
            <Setter Property="IsEditable" Value="True"/>
            <Setter Property="SnapsToDevicePixels" Value="true" />
            <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto" />
            <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto" />
            <Setter Property="ScrollViewer.CanContentScroll" Value="true" />
            <Setter Property="Margin" Value="2" />
            <Setter Property="MinHeight" Value="20" />
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="ComboBox">
                        <Grid>
                            <VisualStateManager.VisualStateGroups>
                                <VisualStateGroup x:Name="CommonStates">
                                    <VisualState x:Name="Normal"/>
                                    <VisualState x:Name="MouseOver"/>
                                    <VisualState x:Name="Disabled"/>
                                </VisualStateGroup>
                            </VisualStateManager.VisualStateGroups>
                            <ToggleButton x:Name="MyToggleButton"
                                          Grid.Column="2"
                                          ClickMode="Press"
                                          Focusable="false"
                                          IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}"
                                          Template="{StaticResource ComboBoxToggleButton}"/>

                            <ContentPresenter Margin="3,3,23,3" 
                                              Content="{TemplateBinding SelectionBoxItem}"
                                              ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}"
                                              ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}"
                                              HorizontalAlignment="Left"
                                              IsHitTestVisible="False"
                                              x:Name="ContentSite"
                                              VerticalAlignment="Center" />

                            <TextBox Style="{x:Null}" 
                                     x:Name="PART_EditableTextBox" 
                                     Margin="3,3,23,3" 
                                     Background="Transparent"
                                     Focusable="True"
                                     HorizontalAlignment="Left"
                                     IsReadOnly="{TemplateBinding IsReadOnly}"
                                     Template="{StaticResource ComboBoxTextBox}" 
                                     VerticalAlignment="Center" 
                                     Visibility="Hidden" />

                            <Popup AllowsTransparency="True" Focusable="False" IsOpen="{TemplateBinding IsDropDownOpen}" x:Name="Popup" Placement="Bottom" PopupAnimation="Fade">
                                <Grid MaxHeight="{TemplateBinding MaxDropDownHeight}" MinWidth="{TemplateBinding ActualWidth}" x:Name="DropDown" SnapsToDevicePixels="True">
                                    <Border x:Name="DropDownBorder" Background="White" BorderBrush="{StaticResource BorderDarkMainBrush}" BorderThickness="1" CornerRadius="0" />
                                    <ScrollViewer Margin="2" SnapsToDevicePixels="True">
                                        <StackPanel KeyboardNavigation.DirectionalNavigation="Contained" IsItemsHost="True" TextBlock.Foreground="Black" />
                                    </ScrollViewer>
                                </Grid>
                            </Popup>
                        </Grid>
                        <ControlTemplate.Triggers>
                            <Trigger Property="HasItems" Value="false">
                                <Setter Property="MinHeight" TargetName="DropDownBorder" Value="95" />
                            </Trigger>
                            <Trigger Property="IsGrouping" Value="true">
                                <Setter Property="ScrollViewer.CanContentScroll" Value="false" />
                            </Trigger>
                            <Trigger Property="IsEditable" Value="true">
                                <Setter Property="IsTabStop" Value="false" />
                                <Setter Property="Visibility" TargetName="PART_EditableTextBox" Value="Visible" />
                                <Setter Property="Visibility" TargetName="ContentSite" Value="Hidden" />
                            </Trigger>
                        </ControlTemplate.Triggers>

                    </ControlTemplate>
                </Setter.Value>
            </Setter>
            <Style.Triggers>
                <Trigger Property="IsFocused" Value="True">
                    <Setter Property="Background" Value="Transparent" />
                </Trigger>
            </Style.Triggers>
        </Style>

Answer 1

使用第一个XAML块，您将添加一个ToggleButton作为ComboBox的子级。所以你可以用这种方式循环所有项目：

foreach(ToggleButton btn in someComboBox.Items)
{
   btn.Click += event_handler;
}

但我不明白你需要什么！： - ）

切换按钮（在组合框内）附加点击处理程序

1 个答案: