WPF 在带有组合框的组合框中查找文本框控件.模板

Question

此问题是带有复选框和带有搜索字段的文本框的 WPF 组合框的扩展

在我的窗口中添加UserControl，如下所示

<Usercontrols:MultiSelectComboBox x:Name="multiCombo" HorizontalAlignment="Left" Height="28" VerticalAlignment="Top" Width="235" Margin="81,27,0,0"/>

我有我的组合盒。模板在我的组合框中如下所示

<ComboBox>
<ComboBox.Template>
<ControlTemplate TargetType="ComboBox">
<Grid Name="control" >
<ToggleButton 
x:Name="ToggleButton" 
Grid.Column="2" IsChecked="{Binding Path=IsDropDownOpen,Mode=TwoWay,RelativeSource={RelativeSource TemplatedParent}}"
Focusable="false"                           
ClickMode="Press" HorizontalContentAlignment="Left" >
<ToggleButton.Template>
<ControlTemplate>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="18"/>
</Grid.ColumnDefinitions>
<Border
x:Name="Border" 
Grid.ColumnSpan="2"
CornerRadius="2"
Background="White"
BorderBrush="Silver"
BorderThickness="1,1,1,1" />
<Border 
x:Name="BorderComp" 
Grid.Column="0"
CornerRadius="2" 
Margin="1" 
Background="White"
BorderBrush="Black"
BorderThickness="0,0,0,0" >
<TextBlock Text="{Binding Path=Text,RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=UserControl}}" 
Background="White" Padding="3" />
</Border>
<Path 
x:Name="Arrow"
Grid.Column="1"     
Fill="Black"
HorizontalAlignment="Center"
VerticalAlignment="Center"
Data="M 0 0 L 4 4 L 8 0 Z"/>
</Grid>
</ControlTemplate>
</ToggleButton.Template>
</ToggleButton>
<Popup 
Name="Popup"
Placement="Bottom"                        
AllowsTransparency="True" 
Focusable="False"  IsOpen="{TemplateBinding IsDropDownOpen}"
PopupAnimation="Slide">
<Grid 
Name="DropDown"
SnapsToDevicePixels="True"  
MinWidth="{TemplateBinding ActualWidth}"
MaxHeight="{TemplateBinding MaxDropDownHeight}">
<Border 
x:Name="DropDownBorder"
BorderThickness="1" Background="White"
BorderBrush="Black"/>
<ScrollViewer Margin="4,6,4,6" SnapsToDevicePixels="True" DataContext="{Binding}">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<TextBox Name="TextBox"  Text="{Binding Path=Text, Mode=TwoWay}" TextChanged="TextBox_TextChanged" />
<StackPanel Grid.Row="2" IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
</Grid>
</ScrollViewer>
</Grid>
</Popup>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="HasItems" Value="false">
<Setter TargetName="DropDownBorder" Property="MinHeight" Value="95"/>
</Trigger>
<Trigger SourceName="Popup" Property="Popup.AllowsTransparency" Value="true">
<Setter TargetName="DropDownBorder" Property="CornerRadius" Value="4"/>
<Setter TargetName="DropDownBorder" Property="Margin" Value="0,2,0,0"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</ComboBox.Template>
</ComboBox>

我正在尝试在UserControl内找到TextBox控件，其中包含文本框更改事件上的ComboBox和ComboBox.ItemTemplate。我尝试如下，但我得到空

private void multiCombo_TextChange(object sender, EventArgs e)
{
Grid TxtBox = (Grid)multiCombo.Template.FindName("control", multiCombo);
//TextBox textBox = sender as TextBox;
MessageBox.Show(TxtBox.ToString());
}

Answer 1

您可以强制转换TextChangedEventArgs的OriginalSource属性：

private void multiCombo_TextChange(object sender, TextChangedEventArgs e)
{
TextBox textBox = e.OriginalSource as TextBox;
//...
}