为什么此DropdownMenu在WPF中不起作用

<ComboBox ItemsSource="{Binding YourDataSource}" />

<ComboBox SelectionChanged="YourSelectionChangedHandler" />

private void YourSelectionChangedHandler(object sender, SelectionChangedEventArgs e)
{
    // 处理选择变化的逻辑
}

<Style TargetType="ComboBox">
    <!-- 你的样式设置 -->
</Style>

<Window x:Class="YourNamespace.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <ComboBox x:Name="myComboBox" SelectionChanged="MyComboBox_SelectionChanged">
            <ComboBoxItem Content="Option 1"/>
            <ComboBoxItem Content="Option 2"/>
            <ComboBoxItem Content="Option 3"/>
        </ComboBox>
    </Grid>
</Window>

namespace YourNamespace
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void MyComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            // 处理选择变化的逻辑
            var selectedValue = ((ComboBox)sender).SelectedItem;
            MessageBox.Show($"Selected: {selectedValue}");
        }
    }
}