没有下拉按钮的WPF ComboBox

问题描述 投票：0回答：4

我想要一个

ComboBox
，它没有下拉按钮，但当我单击
ComboBox
中的文本时仍然可以打开。 这可以通过 WPF 实现吗
ComboBox
？

wpf user-interface xaml controls combobox
4个回答
28
投票

这是可能的，但你需要重新设计它才能达到完美。您可以通过覆盖系统参数来实现大部分目的，如下所示：

<ComboBox xmlns:sys="clr-namespace:System;assembly=mscorlib">
    <ComboBox.Resources>
        <sys:Double x:Key="{x:Static SystemParameters.VerticalScrollBarWidthKey}">0</sys:Double>
    </ComboBox.Resources>
    <ComboBoxItem>One</ComboBoxItem>
    <ComboBoxItem>Two</ComboBoxItem>
    <ComboBoxItem>Three</ComboBoxItem>
</ComboBox>

但是，它并不完美，因为焦点矩形仍然假设存在下拉按钮。

14
投票

所有 WPF 控件都是“无外观”的，因此您可以完全重新定义它们的外观。然而，这并不简单，对于 ComboBox 来说更不简单。 ComboBox 使用两个模板之一，具体取决于它是否可编辑。不可编辑的版本使用 ToggleButton 作为控件外观，因此您只需删除箭头绘制即可（见下文）。可编辑版本使用 TextBox 和 ToggleButton，如果没有 ToggleButton，则不会打开。这是一个没有 ToggleButton 的模板；您可以添加代码来处理可编辑模板上的点击。 （或者，如果您不需要编辑，您可以将 IsEditable 强制为 false 并完成它。）

注意：这是 Aero 模板并使用 Aero chrome，因此不会在其他主题中显示。为此，您需要提取每个主题的模板并进行适当的更改或删除主题镶边并绘制您自己的边框。

添加此命名空间定义并添加对PresentationFramework.Aero的引用：

xmlns:t="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Aero"

然后将以下内容添加到您的窗口/控件资源中：

    <Style x:Key="ComboBoxFocusVisual">
        <Setter Property="Control.Template">
            <Setter.Value>
                <ControlTemplate>
                    <Rectangle Stroke="Black" StrokeDashArray="1 2" StrokeThickness="1" Margin="4,4,21,4" SnapsToDevicePixels="true"/>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <LinearGradientBrush x:Key="ButtonNormalBackground" EndPoint="0,1" StartPoint="0,0">
        <GradientStop Color="#F3F3F3" Offset="0"/>
        <GradientStop Color="#EBEBEB" Offset="0.5"/>
        <GradientStop Color="#DDDDDD" Offset="0.5"/>
        <GradientStop Color="#CDCDCD" Offset="1"/>
    </LinearGradientBrush>
    <SolidColorBrush x:Key="ButtonNormalBorder" Color="#FF707070"/>
    <Geometry x:Key="DownArrowGeometry">M 0 0 L 3.5 4 L 7 0 Z</Geometry>
    <Style x:Key="ComboBoxReadonlyToggleButton" TargetType="{x:Type ToggleButton}">
        <Setter Property="OverridesDefaultStyle" Value="true"/>
        <Setter Property="IsTabStop" Value="false"/>
        <Setter Property="Focusable" Value="false"/>
        <Setter Property="ClickMode" Value="Press"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ToggleButton}">
                    <t:ButtonChrome x:Name="Chrome" SnapsToDevicePixels="true" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" RenderMouseOver="{TemplateBinding IsMouseOver}" RenderPressed="{TemplateBinding IsPressed}">
                        <!-- Remove ToggleButton appearance; we still need the ToggleButton because it displays the content.
                        <Grid HorizontalAlignment="Right" Width="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}">
                            <Path x:Name="Arrow" Fill="Black" HorizontalAlignment="Center" Margin="3,1,0,0" VerticalAlignment="Center" Data="{StaticResource DownArrowGeometry}"/>
                        </Grid>
                        -->
                    </t:ButtonChrome>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsChecked" Value="true">
                            <Setter Property="RenderPressed" TargetName="Chrome" Value="true"/>
                        </Trigger>
                        <!-- Remove ToggleButton appearance trigger
                        <Trigger Property="IsEnabled" Value="false">
                            <Setter Property="Fill" TargetName="Arrow" Value="#AFAFAF"/>
                        </Trigger>
                        -->
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <LinearGradientBrush x:Key="TextBoxBorder" EndPoint="0,20" StartPoint="0,0" MappingMode="Absolute">
        <GradientStop Color="#ABADB3" Offset="0.05"/>
        <GradientStop Color="#E2E3EA" Offset="0.07"/>
        <GradientStop Color="#E3E9EF" Offset="1"/>
    </LinearGradientBrush>
    <Style x:Key="ComboBoxEditableTextBox" TargetType="{x:Type TextBox}">
        <Setter Property="OverridesDefaultStyle" Value="true"/>
        <Setter Property="AllowDrop" Value="true"/>
        <Setter Property="MinWidth" Value="0"/>
        <Setter Property="MinHeight" Value="0"/>
        <Setter Property="FocusVisualStyle" Value="{x:Null}"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type TextBox}">
                    <ScrollViewer x:Name="PART_ContentHost" Background="Transparent" Focusable="false" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Hidden"/>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <Style x:Key="ComboBoxToggleButton" TargetType="{x:Type ToggleButton}">
        <Setter Property="OverridesDefaultStyle" Value="true"/>
        <Setter Property="IsTabStop" Value="false"/>
        <Setter Property="Focusable" Value="false"/>
        <Setter Property="ClickMode" Value="Press"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ToggleButton}">
                    <t:ButtonChrome x:Name="Chrome" Width="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}" SnapsToDevicePixels="true" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" RenderMouseOver="{TemplateBinding IsMouseOver}" RenderPressed="{TemplateBinding IsPressed}" RoundCorners="false">
                        <Path x:Name="Arrow" Fill="Black" HorizontalAlignment="Center" Margin="0,1,0,0" VerticalAlignment="Center" Data="{StaticResource DownArrowGeometry}"/>
                    </t:ButtonChrome>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsChecked" Value="true">
                            <Setter Property="RenderPressed" TargetName="Chrome" Value="true"/>
                        </Trigger>
                        <Trigger Property="IsEnabled" Value="false">
                            <Setter Property="Fill" TargetName="Arrow" Value="#AFAFAF"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <ControlTemplate x:Key="ComboBoxEditableTemplate" TargetType="{x:Type ComboBox}">
        <Grid x:Name="Placement" SnapsToDevicePixels="true">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*"/>
                <ColumnDefinition Width="Auto"/>
            </Grid.ColumnDefinitions>
            <Popup x:Name="PART_Popup" AllowsTransparency="true" IsOpen="{Binding IsDropDownOpen, RelativeSource={RelativeSource TemplatedParent}}" Placement="Bottom" PopupAnimation="{DynamicResource {x:Static SystemParameters.ComboBoxPopupAnimationKey}}" Grid.ColumnSpan="2">
                <t:SystemDropShadowChrome x:Name="Shdw" MaxHeight="{TemplateBinding MaxDropDownHeight}" MinWidth="{Binding ActualWidth, ElementName=Placement}" Color="Transparent">
                    <Border x:Name="DropDownBorder" Background="{DynamicResource {x:Static SystemColors.WindowBrushKey}}" BorderBrush="{DynamicResource {x:Static SystemColors.WindowFrameBrushKey}}" BorderThickness="1">
                        <ScrollViewer>
                            <ItemsPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" KeyboardNavigation.DirectionalNavigation="Contained"/>
                        </ScrollViewer>
                    </Border>
                </t:SystemDropShadowChrome>
            </Popup>
            <t:ListBoxChrome x:Name="Border" Grid.ColumnSpan="2" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" RenderFocused="{TemplateBinding IsKeyboardFocusWithin}" RenderMouseOver="{TemplateBinding IsMouseOver}"/>
            <TextBox x:Name="PART_EditableTextBox" Margin="{TemplateBinding Padding}" Style="{StaticResource ComboBoxEditableTextBox}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}" IsReadOnly="{Binding IsReadOnly, RelativeSource={RelativeSource TemplatedParent}}"/>
            <!-- Remove the ToggleButton button; now you make the textbox clickable....
                <ToggleButton Style="{StaticResource ComboBoxToggleButton}" Grid.Column="1" IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}"/>
            -->
        </Grid>
        <ControlTemplate.Triggers>
            <Trigger Property="IsKeyboardFocusWithin" Value="true">
                <Setter Property="Foreground" Value="Black"/>
            </Trigger>
            <Trigger Property="IsDropDownOpen" Value="true">
                <Setter Property="RenderFocused" TargetName="Border" Value="true"/>
            </Trigger>
            <Trigger Property="HasItems" Value="false">
                <Setter Property="Height" TargetName="DropDownBorder" Value="95"/>
            </Trigger>
            <Trigger Property="IsEnabled" Value="false">
                <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
                <Setter Property="Background" Value="#FFF4F4F4"/>
            </Trigger>
            <Trigger Property="IsGrouping" Value="true">
                <Setter Property="ScrollViewer.CanContentScroll" Value="false"/>
            </Trigger>
            <Trigger Property="HasDropShadow" SourceName="PART_Popup" Value="true">
                <Setter Property="Margin" TargetName="Shdw" Value="0,0,5,5"/>
                <Setter Property="Color" TargetName="Shdw" Value="#71000000"/>
            </Trigger>
        </ControlTemplate.Triggers>
    </ControlTemplate>
    <Style x:Key="ButtonlessComboBoxStyle" TargetType="{x:Type ComboBox}">
        <Setter Property="FocusVisualStyle" Value="{StaticResource ComboBoxFocusVisual}"/>
        <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.WindowTextBrushKey}}"/>
        <Setter Property="Background" Value="{StaticResource ButtonNormalBackground}"/>
        <Setter Property="BorderBrush" Value="{StaticResource ButtonNormalBorder}"/>
        <Setter Property="BorderThickness" Value="1"/>
        <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto"/>
        <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto"/>
        <Setter Property="Padding" Value="4,3"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ComboBox}">
                    <Grid x:Name="MainGrid" SnapsToDevicePixels="true">
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="*"/>
                            <ColumnDefinition MinWidth="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}" Width="0"/>
                        </Grid.ColumnDefinitions>
                        <Popup x:Name="PART_Popup" Margin="1" AllowsTransparency="true" IsOpen="{Binding IsDropDownOpen, RelativeSource={RelativeSource TemplatedParent}}" Placement="Bottom" PopupAnimation="{DynamicResource {x:Static SystemParameters.ComboBoxPopupAnimationKey}}" Grid.ColumnSpan="2">
                            <t:SystemDropShadowChrome x:Name="Shdw" MaxHeight="{TemplateBinding MaxDropDownHeight}" MinWidth="{Binding ActualWidth, ElementName=MainGrid}" Color="Transparent">
                                <Border x:Name="DropDownBorder" Background="{DynamicResource {x:Static SystemColors.WindowBrushKey}}" BorderBrush="{DynamicResource {x:Static SystemColors.WindowFrameBrushKey}}" BorderThickness="1">
                                    <ScrollViewer CanContentScroll="true">
                                        <ItemsPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" KeyboardNavigation.DirectionalNavigation="Contained"/>
                                    </ScrollViewer>
                                </Border>
                            </t:SystemDropShadowChrome>
                        </Popup>
                        <ToggleButton Style="{StaticResource ComboBoxReadonlyToggleButton}" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" Grid.ColumnSpan="2" IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}"/>
                        <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" IsHitTestVisible="false" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" Content="{TemplateBinding SelectionBoxItem}" ContentStringFormat="{TemplateBinding SelectionBoxItemStringFormat}" ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}" ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}"/>
                    </Grid>
                    <ControlTemplate.Triggers>
                        <Trigger Property="HasDropShadow" SourceName="PART_Popup" Value="true">
                            <Setter Property="Margin" TargetName="Shdw" Value="0,0,5,5"/>
                            <Setter Property="Color" TargetName="Shdw" Value="#71000000"/>
                        </Trigger>
                        <Trigger Property="HasItems" Value="false">
                            <Setter Property="Height" TargetName="DropDownBorder" Value="95"/>
                        </Trigger>
                        <Trigger Property="IsEnabled" Value="false">
                            <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
                            <Setter Property="Background" Value="#FFF4F4F4"/>
                        </Trigger>
                        <Trigger Property="IsGrouping" Value="true">
                            <Setter Property="ScrollViewer.CanContentScroll" Value="false"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
        <Style.Triggers>
            <Trigger Property="IsEditable" Value="true">
                <Setter Property="BorderBrush" Value="{StaticResource TextBoxBorder}"/>
                <Setter Property="Background" Value="{DynamicResource {x:Static SystemColors.WindowBrushKey}}"/>
                <Setter Property="IsTabStop" Value="false"/>
                <Setter Property="Padding" Value="3"/>
                <Setter Property="Template" Value="{StaticResource ComboBoxEditableTemplate}"/>
            </Trigger>
        </Style.Triggers>
    </Style>

然后使用：

<ComboBox HorizontalAlignment="Left" Width="120" Style="{DynamicResource ButtonlessComboBoxStyle}">
    <ComboBox.Items>
        <ComboBoxItem>One</ComboBoxItem>
        <ComboBoxItem>Two</ComboBoxItem>
        <ComboBoxItem>Three</ComboBoxItem>
    </ComboBox.Items>
</ComboBox>

<ComboBox HorizontalAlignment="Left" Width="120" IsEditable="True" Style="{DynamicResource ButtonlessComboBoxStyle}">
    <ComboBox.Items>
        <ComboBoxItem>One</ComboBoxItem>
        <ComboBoxItem>Two</ComboBoxItem>
        <ComboBoxItem>Three</ComboBoxItem>
    </ComboBox.Items>
</ComboBox>

注意：样式被引用为

DynamicResource
，因为它们依赖于主题镶边，因此需要响应操作系统视觉样式的变化。如果您删除镶边并使用 WPF 边框，那么您应该将它们引用为 
StaticResource
以提高性能。

0
投票

也许这可以帮助你

Dispatcher.BeginInvoke(new Action(() =>
            {
                ToggleButton dropDownButton = GetFirstChildOfType<ToggleButton>(cboMedicos);
                if (dropDownButton != null)
                {
                    dropDownButton.IsEnabled = false;
                }

            }), System.Windows.Threading.DispatcherPriority.Render);




        public static T GetFirstChildOfType<T>(DependencyObject dependencyObject) where T : DependencyObject
        {
            if (dependencyObject == null)
            {
                return null;
            }

            for (var i = 0; i < VisualTreeHelper.GetChildrenCount(dependencyObject); i++)
            {
                var child = VisualTreeHelper.GetChild(dependencyObject, i);

                var result = (child as T) ?? GetFirstChildOfType<T>(child);

                if (result != null)
                {
                    return result;
                }
            }

            return null;
        }
0
投票

这是一篇非常古老的文章，但您也许可以轻松地“破解”它，具体取决于您的 ComboBox 的样式。这是一个快速但肮脏的解决方案，但您可能会发现结果是可以接受的。

组合框需要有一个显式的 

Width=
值。将其放在 
<Border>
内，并给边框一个较小的宽度 - 足以隐藏组合框按钮。

生成的 ComboBox 现在可能看起来有点奇怪（即明显被截断），因为它的右侧边框丢失了。根据其样式/模板，您也许可以通过使用外部边框添加自己的边框来纠正此问题。

完整的示例解决方案：

<Border Width="60" BorderThickness="0,0,1,0" BorderBrush="Gray">
    <ComboBox Width="80">
        <x:String>foo</x:String>
        <x:String>bar</x:String>
    </ComboBox>
</Border>
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