WPF 菜单项行为？

Question

我试图在万维网上四处寻找，但没有成功，我的应用程序中有一个用于打开文件夹的按钮 select 对话框，它是以这种方式实现的：

        <Button Grid.Column="0" Margin="5" Content="Select Folder" Style="{StaticResource MaterialDesignRaisedLightButton}">
            <i:Interaction.Behaviors>
                <FolderDialog:FolderDialogBehavior SetterName="FolderName"></FolderDialog:FolderDialogBehavior>
            </i:Interaction.Behaviors>
        </Button>

现在我需要在菜单项中使用这种行为（当然还有另一个 SetterName），但是我无法找到解决方案来完成我的任务，有人可以帮我吗？

<Menu Background="#292A24" Foreground="Yellow" VerticalAlignment="Top" IsMainMenu="True">
    <MenuItem  Header="_File" Height="35">
        <MenuItem Header="Export to csv">
            <MenuItem.Icon>
                <materialDesign:PackIcon Kind="Export" />
            </MenuItem.Icon>
        </MenuItem>
        <MenuItem Header="Exit" InputGestureText="Ctrl+E">
            <MenuItem.Icon>
                <materialDesign:PackIcon Kind="ExitToApp" />
            </MenuItem.Icon>
        </MenuItem>
    </MenuItem>
</Menu>

Answer 1

菜单项有 its own Click event。所以你必须为 MenuItem

创建新的行为 class

public class FolderDialogBehavior : Behavior<MenuItem>
{
    public string SetterName { get; set; }

    protected override void OnAttached()
    {
        AssociatedObject.Click += OnClick;
    }
    
    protected override void OnDetaching()
    {
        AssociatedObject.Click -= OnClick;
    }

    private void OnClick(object sender, RoutedEventArgs e)
    {
        var dialog = new FolderBrowserDialog();
        var result = dialog.ShowDialog();
        if (result == DialogResult.OK && AssociatedObject.DataContext != null)
        {
            var propertyInfo = AssociatedObject.DataContext.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public)
            .Where(p => p.CanRead && p.CanWrite)
            .Where(p => p.Name.Equals(SetterName))
            .First();

            propertyInfo.SetValue(AssociatedObject.DataContext, dialog.SelectedPath, null);
        }
    }
}

如果你想要单一行为class你可以通过反射定义订阅

private RoutedEvent _clickEvent;

protected override void OnAttached()
{
    var memberInfo = AssociatedObject.GetType().GetProperty("ClickEvent");
    if (memberInfo == null)
    {
        return;
    }
    
    _clickEvent = memberInfo.GetValue(AssociatedObject) as RoutedEvent
    if (_clickEvent == null)
    {
        return;
    }
    
    AssociatedObject.AddHandler(_clickEvent, OnClick);
}

protected override void OnDetaching()
{
    if (_clickEvent == null)
    {
        return;
    }
    
    AssociatedObject.RemoveHandler(_clickEvent, OnClick);
}

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