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Question

我有一个自定义的ComboBox，每个项目（收藏夹而不是收藏夹）是一个Label + Button，然后最后一个项目只有一个按钮来加载所有元素。现在我想添加标题作为第一项，即“收藏夹”。

现在我有：

<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="3*" />
                        <ColumnDefinition Width="Auto" />
                    </Grid.ColumnDefinitions>
                    <Label
                        Content="{Binding}"
                       Width="250" Visibility="{Binding Path=., Converter={StaticResource elementToVisibilityConverter}}" />
                    <Button Name="PART_BUTTON"
                        Grid.Column="1"
                        Content="+"
                        Command="{Binding AddCommandButton, ElementName=root}"
                        CommandParameter="{Binding}"
                        Visibility="{Binding Path=., Converter={StaticResource elementToVisibilityConverter}}"/>
                    <Button Content="Carregar Todos" Margin="5,5"
                                    Command="{Binding LoadAllCommandButton, ElementName=root}"
                                    CommandParameter="{Binding ElementName=root, Path=FavoriteType}"
                                    Visibility="{Binding Path=.,Converter={StaticResource elementToVisibilityForAddConverter}}"/>
                </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>

Answer 1

我更喜欢不同的方法，我认为这种方法更容易，也更干净：

我创建了一个空接口IDrawable。我需要放在组合框内的所有类都应继承自IDrawable 我创造了这些：
的 MyLabel：

public class MyLabel : IDrawable { public string text { get; set; } public MyLabel() { this.text = "MYTEXT"; } }

<强> myButton的：

public class MyButton : IDrawable { public string text { get; set; } public MyButton() { this.text = "MYNBUTTON"; } }

<强> MyLabelButton：公共类MyLabelButton：IDrawable { public string labelText {get;组; } public string buttonText {get;组; }

public MyLabelButton() { labelText = "labelText"; buttonText = "buttonText"; } }

这里是xaml

<Window x:Class="WpfApplication1.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:me="clr-namespace:WpfApplication1"> <Window.Resources> <DataTemplate DataType="{x:Type me:MyButton}"> <Button Content="{Binding text}" /> </DataTemplate> <DataTemplate DataType="{x:Type me:MyLabel}"> <TextBlock Text="{Binding text}"/> </DataTemplate> <DataTemplate DataType="{x:Type me:MyLabelButton}"> <StackPanel Orientation="Horizontal"> <Label Content="{Binding labelText}"/> <Button Content="{Binding buttonText}"/> </StackPanel> </DataTemplate> </Window.Resources> <Grid Name="MyGrid"> <ComboBox Name="MyCombo" ItemsSource="{Binding list}" SelectedItem="{Binding sel}" PreviewMouseLeftButtonUp="ComboBox_PreviewMouseLeftButtonUp"/> </Grid> </Window>

和codebehind：

public partial class MainWindow : Window { private IDrawable clicked; public ObservableCollection<IDrawable> list { get; set; } public IDrawable sel { get; set; } public MainWindow() { InitializeComponent(); list = new ObservableCollection<IDrawable>(); list.Add(new MyLabel()); list.Add(new MyLabelButton()); list.Add(new MyButton()); this.DataContext = this; } private void ComboBox_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e) { Point pt = e.GetPosition(MyGrid); clicked = null; VisualTreeHelper.HitTest( MyGrid, null, new HitTestResultCallback(ResultCallback), new PointHitTestParameters(pt)); if (clicked != null) { ((ComboBox)sender).IsDropDownOpen = false; //do something } } private HitTestResultBehavior ResultCallback(HitTestResult result) { DependencyObject parentObject = VisualTreeHelper.GetParent(result.VisualHit); if (parentObject == null) return HitTestResultBehavior.Continue; var v = parentObject as Button; if (v == null) return HitTestResultBehavior.Continue; if (v.DataContext != null && v.DataContext is IDrawable) { clicked = (IDrawable)v.DataContext; return HitTestResultBehavior.Stop; } return HitTestResultBehavior.Continue; } }

结果为

你可以看到我有标准的组合框和自定义元素。我觉得它更好。在代码隐藏中，您可以处理所有内容，例如无法选择第一个标签，调用与按钮关联的命令，是否按下按钮等等。

在ComboBox_PreviewMouseLeftButtonUp我处理了所选项目的点击，以防您在按下所选按钮时想要执行特定操作，而不显示下拉菜单。

这个例子非常简单，你需要更多地定制它并在任何地方使用MVVM 目前你可以按下dropDown菜单中的按钮，如果没有选择该按钮，你可能会想要禁用点击。

修改

ComboBox_PreviewMouseLeftButtonUp应该是这样的：

private void ComboBox_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e) { Point pt = e.GetPosition((ComboBox)sender); clicked = null; VisualTreeHelper.HitTest( (ComboBox)sender, null, new HitTestResultCallback(ResultCallback), new PointHitTestParameters(pt)); if (clicked != null) { ((ComboBox)sender).IsDropDownOpen = false; //do something } }

（将Mygrid替换为(ComboBox)sender

WPF将标头添加到自定义组合框

1 个答案:

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