C# WPF点击窗体内嵌页面按钮隐藏当前窗口打开新窗口问题

问题场景 #

现有WPF窗体使用DockPanel承载Page实现导航功能，需求为点击内嵌Page上的按钮时，隐藏当前宿主窗口、弹出新窗口，原有实现代码未生效。

原有问题代码 #

Page端按钮代码

public partial class SubPnlItems_SK : Page
{
    public SubPnlItems_SK()
    {
        InitializeComponent();
    }

    private void btnAddItems_SK_Click(object sender, RoutedEventArgs e)
    {
        PnlTabMenu_SK tabMenu_SK = new PnlTabMenu_SK();
        PnlAddItem_SK pnlAddItem_SK = new PnlAddItem_SK();
        tabMenu_SK.Visibility = Visibility.Hidden;
        pnlAddItem_SK.ShowDialog();

    }

    private void btnViewItems_SK_Click(object sender, RoutedEventArgs e)
    {

    }
}

宿主窗口代码

public partial class PnlTabMenu_SK : Window
{
    public PnlTabMenu_SK()
    {
        InitializeComponent();
        dockPanel_SK.NavigationService.Navigate(new Uri("SubPnlItems_SK.xaml", UriKind.Relative));
    }

    private void Window_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        this.DragMove();
    }

    private void btn_minimize_Click(object sender, RoutedEventArgs e)
    {
        WindowState = WindowState.Minimized;
    }

    private void btn_close_Click(object sender, RoutedEventArgs e)
    {
        this.Close();
    }

    private void btnItems_SK_Click(object sender, RoutedEventArgs e)
    {
        dockPanel_SK.NavigationService.Navigate(new Uri("SubPnlItems_SK.xaml", UriKind.Relative));

    }

    private void btnISN_SK_Click(object sender, RoutedEventArgs e)
    {
        dockPanel_SK.NavigationService.Navigate(new Uri("SubPnlISN_SK.xaml", UriKind.Relative));
    }

    private void btnMRF_SK_Click(object sender, RoutedEventArgs e)
    {
        dockPanel_SK.NavigationService.Navigate(new Uri("SubPnlMRF_SK.xaml", UriKind.Relative));
    }

    private void btnGRN_SK_Click(object sender, RoutedEventArgs e)
    {
        dockPanel_SK.NavigationService.Navigate(new Uri("SubPnlGRN_SK.xaml", UriKind.Relative));
    }
}

失效原因 #

代码核心错误：按钮点击事件中通过new PnlTabMenu_SK()创建的是一个从未被显示过的全新窗口实例，和当前已经打开、承载Page的宿主窗口完全无关，对这个新实例设置隐藏属性自然不会产生任何效果。

修复方法 #

快速实现：直接获取当前Page所属的宿主窗口 #

WPF的Page类可以通过Window.GetWindow()方法直接获取承载自身的父窗口实例，不需要手动新建，修改按钮点击逻辑即可：

private void btnAddItems_SK_Click(object sender, RoutedEventArgs e)
{
    // 获取当前Page实际挂载的宿主窗口实例
    PnlTabMenu_SK hostWindow = Window.GetWindow(this) as PnlTabMenu_SK;
    if (hostWindow == null) return;
    
    PnlAddItem_SK pnlAddItem_SK = new PnlAddItem_SK();
    hostWindow.Visibility = Visibility.Hidden;
    // 弹窗关闭后自动恢复宿主窗口显示，不需要可删除
    pnlAddItem_SK.Owner = hostWindow;
    pnlAddItem_SK.ShowDialog();
    hostWindow.Visibility = Visibility.Visible;
}

解耦实现：事件通知（符合MVVM规范） #

如果不希望Page直接依赖具体宿主窗口类型，避免耦合，可以通过事件回调让宿主窗口自行处理显示隐藏逻辑：

1. 在Page类中定义点击事件

   public partial class SubPnlItems_SK : Page
   {
       // 新增按钮点击事件
       public event EventHandler AddItemsRequested;
   
       public SubPnlItems_SK()
       {
           InitializeComponent();
       }
   
       private void btnAddItems_SK_Click(object sender, RoutedEventArgs e)
       {
           // 触发事件，不直接操作窗口
           AddItemsRequested?.Invoke(this, EventArgs.Empty);
       }
       // 其余原有代码不变
   }
   

2. 修改宿主窗口导航逻辑，订阅Page事件

   // 替换原有直接传Uri的导航方式
   private void NavigateToItemsPage()
   {
       var itemsPage = new SubPnlItems_SK();
       // 订阅Page的按钮点击事件
       itemsPage.AddItemsRequested += (s, args) =>
       {
           this.Visibility = Visibility.Hidden;
           var addWindow = new PnlAddItem_SK();
           addWindow.ShowDialog();
           this.Visibility = Visibility.Visible;
       };
       dockPanel_SK.NavigationService.Navigate(itemsPage);
   }
   

注意：使用该方式时不能直接传Uri导航，需要手动创建Page实例再传入导航方法，否则无法订阅实例事件。

内容的提问来源于stack exchange，提问作者Tharindu