C# WPF组合框在单击后加载元素
我有一个自定义组合框,现在是这样的:C# WPF组合框在单击后加载元素,c#,wpf,combobox,C#,Wpf,Combobox,我有一个自定义组合框,现在是这样的: <ComboBox x:Name="ComboBoxBtn" VerticalAlignment="Top" HorizontalAlignment="Left" Margin="0,0,0,-1" Width="300" ItemsSource="{Binding Source, RelativeSource={RelativeSource AncestorType=UserControl}
<ComboBox
x:Name="ComboBoxBtn"
VerticalAlignment="Top"
HorizontalAlignment="Left"
Margin="0,0,0,-1"
Width="300"
ItemsSource="{Binding Source, RelativeSource={RelativeSource AncestorType=UserControl}}"
SelectedItem="{Binding Path=Selected, Mode=TwoWay, RelativeSource={RelativeSource AncestorType=UserControl}}"
IsSynchronizedWithCurrentItem="True">
<ComboBox.ItemTemplate>
<DataTemplate>
<Grid Name="PART_GRID">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<Label Content="{Binding}"
Width="250" />
<Button Name="PART_BUTTON"
Grid.Column="1"
Content="+"
Command="{Binding AddCommandButton, ElementName=root}"
CommandParameter="{Binding}" />
</Grid>
<DataTemplate.Triggers>
<DataTrigger Binding="{Binding Favorite}"
Value="True">
<Setter TargetName="PART_GRID"
Property="Background"
Value="#FFE6E6FA" />
<Setter TargetName="PART_BUTTON"
Property="Content"
Value="-" />
<Setter TargetName="PART_BUTTON"
Property="Command"
Value="{Binding RemoveCommandButton, ElementName=root}" />
</DataTrigger>
</DataTemplate.Triggers>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
基本上,我的源代码是一个ObservableCollection,它包含的元素可能是最喜欢的,也可能不是,在每种情况下,它们以不同的方式呈现。现在,我希望当组合框加载时,只加载最喜欢的项目,并在最后添加一个按钮“全部加载”。单击时,将其余元素加载到我的组合框中
我不知道如何以不同的方式创建最后一个项目(只是一个按钮),关于加载其余部分,我想我可以从收藏中最喜欢的项目开始,然后单击按钮将其余部分添加到列表中。我说得对吗?编辑组合框的模板(右键单击控件->编辑模板->编辑副本…),并在名为
部分弹出窗口的弹出窗口中,在包含项目resenter
的滚动查看器的周围添加一个网格。为网格定义两行,其底部自动调整大小,然后在第二行的网格中添加一个按钮,该按钮可用于加载其他项目
下面是一个示例控件模板:
<ControlTemplate x:Key="ComboBoxTemplate" TargetType="{x:Type ComboBox}">
<Grid x:Name="templateRoot" SnapsToDevicePixels="true">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition MinWidth="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}" Width="0"/>
</Grid.ColumnDefinitions>
<Popup x:Name="PART_Popup" AllowsTransparency="true" Grid.ColumnSpan="2" IsOpen="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Margin="1" PopupAnimation="{DynamicResource {x:Static SystemParameters.ComboBoxPopupAnimationKey}}" Placement="Bottom">
<Themes:SystemDropShadowChrome x:Name="shadow" Color="Transparent" MaxHeight="{TemplateBinding MaxDropDownHeight}" MinWidth="{Binding ActualWidth, ElementName=templateRoot}">
<Border x:Name="dropDownBorder" BorderBrush="{DynamicResource {x:Static SystemColors.WindowFrameBrushKey}}" BorderThickness="1" Background="{DynamicResource {x:Static SystemColors.WindowBrushKey}}">
<Grid> <!-- Add this grid -->
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<ScrollViewer x:Name="DropDownScrollViewer">
<Grid x:Name="grid" RenderOptions.ClearTypeHint="Enabled">
<Canvas x:Name="canvas" HorizontalAlignment="Left" Height="0" VerticalAlignment="Top" Width="0">
<Rectangle x:Name="opaqueRect" Fill="{Binding Background, ElementName=dropDownBorder}" Height="{Binding ActualHeight, ElementName=dropDownBorder}" Width="{Binding ActualWidth, ElementName=dropDownBorder}"/>
</Canvas>
<ItemsPresenter x:Name="ItemsPresenter" KeyboardNavigation.DirectionalNavigation="Contained" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</Grid>
</ScrollViewer>
<!-- Add this button -->
<Button Grid.Row="1" Content="Load All" HorizontalAlignment="Stretch" />
</Grid>
</Border>
</Themes:SystemDropShadowChrome>
</Popup>
<ToggleButton x:Name="toggleButton" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Grid.ColumnSpan="2" IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource ComboBoxToggleButton}"/>
<ContentPresenter x:Name="contentPresenter" ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}" ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}" Content="{TemplateBinding SelectionBoxItem}" ContentStringFormat="{TemplateBinding SelectionBoxItemStringFormat}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" IsHitTestVisible="false" Margin="{TemplateBinding Padding}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="HasDropShadow" SourceName="PART_Popup" Value="true">
<Setter Property="Margin" TargetName="shadow" Value="0,0,5,5"/>
<Setter Property="Color" TargetName="shadow" Value="#71000000"/>
</Trigger>
<Trigger Property="HasItems" Value="false">
<Setter Property="Height" TargetName="dropDownBorder" Value="95"/>
</Trigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="IsGrouping" Value="true"/>
<Condition Property="VirtualizingPanel.IsVirtualizingWhenGrouping" Value="false"/>
</MultiTrigger.Conditions>
<Setter Property="ScrollViewer.CanContentScroll" Value="false"/>
</MultiTrigger>
<Trigger Property="ScrollViewer.CanContentScroll" SourceName="DropDownScrollViewer" Value="false">
<Setter Property="Canvas.Top" TargetName="opaqueRect" Value="{Binding VerticalOffset, ElementName=DropDownScrollViewer}"/>
<Setter Property="Canvas.Left" TargetName="opaqueRect" Value="{Binding HorizontalOffset, ElementName=DropDownScrollViewer}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
看起来是这样的:
然后,您可以使用该按钮使源代码更新(通过单击事件处理程序或命令)
希望有帮助。您可以使用“菜单”而不是“组合框”,现在它看起来可能不同,但“菜单”可以展开并显示子菜单。问题是我需要一个选定的项目。我不能创建如下触发器:?