WPF 组合框显示替代文本

发布于 2024-11-26 13:56:04 字数 2176 浏览 6 评论 0 原文

我正在尝试将 WPF 组合框按钮的文本更改为非实际选定项目的自定义内容。组合框控件使用自定义数据模板进行设置，该模板允许它包含复选框，我想要做的是显示“无选定”、[SelectedItem.Text] 或“多个选定”，具体取决于是否选中零个项目，一个是已检查或已检查多项。我在这里找到了一个解决方案，其中涉及添加一个新的文本块实例，该实例可以显示此文本，然后将其文本设置为我想要显示的内容。这非常有效，直到有人单击复选框标签旁边的区域并且该项目的文本显示在我的自定义文本块下方，导致奇怪的重叠问题。

我的假设是某种转换器（就我而言，它可以替换自定义文本块 - 没有偏好），但我不完全确定如何应用它。这是到目前为止我的 XAML：

<Grid Grid.Row="4" Grid.Column="1">
     <Grid.RowDefinitions>
          <RowDefinition Height="Auto" />
          <RowDefinition Height="Auto" />
     </Grid.RowDefinitions>
<ComboBox x:Name="SubjectMatterList" Style="{StaticResource ComboBox}" ItemsSource="{Binding SubjectMatters}" Visibility="{Binding AdjunctListVisibility}">
    <ComboBox.ItemTemplate>
        <DataTemplate>
            <StackPanel Orientation="Horizontal" MinWidth="125" MaxWidth="125" Margin="6">
                <CheckBox Content="{Binding Name}">
                    <i:Interaction.Triggers>
                        <i:EventTrigger EventName="Checked">
                            <mvvm:EventToCommand Command="{Binding DataContext.SubjectMatterSelectedCommand, ElementName=GradeLevelList}" CommandParameter="{Binding}" />
                        </i:EventTrigger>
                        <i:EventTrigger EventName="Unchecked">
                            <mvvm:EventToCommand Command="{Binding DataContext.SubjectMatterDeselectedCommand, ElementName=GradeLevelList}" CommandParameter="{Binding}" />
                        </i:EventTrigger>
                    </i:Interaction.Triggers>
                </CheckBox>
            </StackPanel>
        </DataTemplate>
    </ComboBox.ItemTemplate>
</ComboBox>
<TextBlock IsHitTestVisible="False" x:Name="SelectedSubjectMatter" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="10" Padding="10,6,0,6" Text="{Binding ComboBoxSubjectMatterText}" Visibility="{Binding AdjunctListVisibility}" />
<TextBlock Text="{Binding SelectedSubjectMatterText}" Grid.Row="1" Margin="10" Visibility="{Binding SubjectMatterSelectedVisibility}" />

原文

I am trying to change the text of a WPF combobox button to something custom that isn't an actual selected item. The combobox control is setup with a custom datatemplate that allows it to contain checkboxes and what I'm trying to do is display "None Selected", [SelectedItem.Text] or "Multiple Selected" depending on whether zero items are checked, one is checked or more than one is checked. I found one solution on here that involved adding a new textblock instance that could display this text and then set the text of it to what I want to display. This works great until someone clicks and area next to the label of the checkbox and the text of that item shows up underneath my custom textblock causing weird overlap issues.

My assumption is a converter of some kind (which can replace the custom textblock as far as I'm concerned - no preference there), but I'm not entirely sure how to apply it. Here is my XAML thus far:

<Grid Grid.Row="4" Grid.Column="1">
     <Grid.RowDefinitions>
          <RowDefinition Height="Auto" />
          <RowDefinition Height="Auto" />
     </Grid.RowDefinitions>
<ComboBox x:Name="SubjectMatterList" Style="{StaticResource ComboBox}" ItemsSource="{Binding SubjectMatters}" Visibility="{Binding AdjunctListVisibility}">
    <ComboBox.ItemTemplate>
        <DataTemplate>
            <StackPanel Orientation="Horizontal" MinWidth="125" MaxWidth="125" Margin="6">
                <CheckBox Content="{Binding Name}">
                    <i:Interaction.Triggers>
                        <i:EventTrigger EventName="Checked">
                            <mvvm:EventToCommand Command="{Binding DataContext.SubjectMatterSelectedCommand, ElementName=GradeLevelList}" CommandParameter="{Binding}" />
                        </i:EventTrigger>
                        <i:EventTrigger EventName="Unchecked">
                            <mvvm:EventToCommand Command="{Binding DataContext.SubjectMatterDeselectedCommand, ElementName=GradeLevelList}" CommandParameter="{Binding}" />
                        </i:EventTrigger>
                    </i:Interaction.Triggers>
                </CheckBox>
            </StackPanel>
        </DataTemplate>
    </ComboBox.ItemTemplate>
</ComboBox>
<TextBlock IsHitTestVisible="False" x:Name="SelectedSubjectMatter" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="10" Padding="10,6,0,6" Text="{Binding ComboBoxSubjectMatterText}" Visibility="{Binding AdjunctListVisibility}" />
<TextBlock Text="{Binding SelectedSubjectMatterText}" Grid.Row="1" Margin="10" Visibility="{Binding SubjectMatterSelectedVisibility}" />