Question

是否有机会更改仅在单击左侧箭头时打开的wpf组合框？通常，您可以单击任意位置将其打开。我不要。

谢谢

Answer 1

通常，您可以单击任意位置将其打开。我不要。

然后，您应该为ToggleButton创建一个自定义模板。 Yan在Visual Studio或Blend中的设计模式下右键单击ComboBox元素，然后选择“编辑模板”->“编辑副本”。

这会将默认模板复制到您的XAML标记中，然后您可以根据需要对其进行编辑。寻找一个Style和一个x:Key的“ ComboBoxToggleButton”，然后修改这个ControlTemplate。

Answer 2

我设法使其与以下代码一起使用。请注意，我正在使用Materialdesign，如果不使用它，则必须对其进行一些更改。

App.xaml中的代码

  <Style x:Key="MaterialDesignComboBox2" TargetType="{x:Type ComboBox}">
                <Setter Property="FocusVisualStyle" Value="{x:Null}"/>
                <Setter Property="Background" Value="Transparent"/>
                <Setter Property="BorderBrush" Value="{DynamicResource MaterialDesignTextBoxBorder}"/>
                <Setter Property="Foreground" Value="{Binding RelativeSource={RelativeSource AncestorType={x:Type FrameworkElement}}, Path=(TextElement.Foreground)}"/>
                <Setter Property="BorderThickness" Value="0 0 0 1"/>
                <Setter Property="ItemContainerStyle" Value="{StaticResource MaterialDesignComboBoxItemSelectedCollapsedStyle}" />
                <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto" />
                <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto" />
                <Setter Property="Padding" Value="0 6 0 6" />
                <Setter Property="VerticalContentAlignment" Value="Top" />
                <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
                <Setter Property="HorizontalAlignment" Value="Stretch"/>
                <Setter Property="VerticalAlignment" Value="Center"/>
                <Setter Property="ScrollViewer.CanContentScroll" Value="true" />
                <Setter Property="ScrollViewer.PanningMode" Value="Both" />
                <Setter Property="Stylus.IsFlicksEnabled" Value="False" />
                <Setter Property="Validation.ErrorTemplate" Value="{StaticResource MaterialDesignValidationErrorTemplate}"/>
                <Setter Property="wpf:TextFieldAssist.TextBoxViewMargin" Value="1 0 1 0" />
                <Setter Property="Template" Value="{StaticResource MaterialDesignFloatingHintComboBoxTemplate2}" />
                <Style.Triggers>
                    <Trigger Property="IsKeyboardFocused" Value="true">
                        <Setter Property="BorderBrush" Value="{DynamicResource PrimaryHueMidBrush}" />
                    </Trigger>
                    <Trigger Property="IsKeyboardFocusWithin" Value="true">
                        <Setter Property="BorderBrush" Value="{DynamicResource PrimaryHueMidBrush}" />
                    </Trigger>
                    <Trigger Property="IsEditable" Value="true">
                        <Setter Property="IsTabStop" Value="false" />
                        <!-- designer prefers hard bool -->
                        <Setter Property="wpf:ComboBoxAssist.ShowSelectedItem" Value="{StaticResource TrueValue}" />
                    </Trigger>
                    <!-- designer prefers hard bool -->
                    <Trigger Property="wpf:ComboBoxAssist.ShowSelectedItem" Value="{StaticResource TrueValue}" >
                        <Setter Property="ItemContainerStyle" Value="{StaticResource MaterialDesignComboBoxItemStyle}" />
                    </Trigger>
                </Style.Triggers>
            </Style>

        <Style x:Key="MaterialDesignFloatingHintComboBox2"
               BasedOn="{StaticResource MaterialDesignComboBox2}"
               TargetType="{x:Type ComboBox}">
            <Setter Property="wpf:HintAssist.IsFloating" Value="True"/>
        </Style>

Helperclass EditableComboBox

public static class EditableComboBox
{
    public static int GetMaxLength(DependencyObject obj)
    {
        return (int)obj.GetValue(MaxLengthProperty);
    }

    public static void SetMaxLength(DependencyObject obj, int value)
    {
        obj.SetValue(MaxLengthProperty, value);
    }

    public static readonly DependencyProperty MaxLengthProperty = DependencyProperty.RegisterAttached("MaxLength", typeof(int), typeof(EditableComboBox), new UIPropertyMetadata(OnMaxLenghtChanged));

    private static void OnMaxLenghtChanged(DependencyObject obj, DependencyPropertyChangedEventArgs args)
    {
        if (!(obj is ComboBox comboBox)) return;

        comboBox.Loaded +=
            (s, e) =>
            {
                var textBox = comboBox.FindChild("PART_EditableTextBox", typeof(TextBox));
                if (textBox == null) return;

                textBox.SetValue(TextBox.MaxLengthProperty, args.NewValue);
            };
    }
}

以及视图中的组合框本身

 <ComboBox materialDesign:HintAssist.Hint="{lex:Loc ordernumber}" Style="{StaticResource MaterialDesignFloatingHintComboBox2}"   Text="{Binding SalesOrderNumber}" Margin="0 0 40 0" FontSize="22" Width="250"
              IsEditable="True" DisplayMemberPath="Identifier" SelectedItem="{Binding SelectedSalesOrder}"
              ItemsSource="{Binding LastSalesOrders}" IsTextSearchEnabled="False" utility:EditableComboBox.MaxLength="10"  x:Name="TbOrder" >
            <ComboBox.InputBindings>
                <KeyBinding Command="{Binding OpenSalesOrderOrCustomerCommand}" Key="Return" />
            </ComboBox.InputBindings>

            <ComboBox.ContextMenu>
                <ContextMenu>
                    <MenuItem Header="{lex:Loc paste}" Command="{Binding PasteOrdernumberCommand}" />
                </ContextMenu>
            </ComboBox.ContextMenu>
  </ComboBox>

WPF组合框应仅在箭头上打开

2 个答案: