为Caliburn托管窗口始终启用顶部

Question

我有以下ViewModel，我正在使用Caliburn Micro。 IWindowManager实例已正确解析并且所有代码均可正常工作。正如TODO评论所示，我需要获取对当前窗口的引用，以便切换AlwaysOnTop属性。我怎样才能做到这一点？

namespace CaliburnWizardPlay 
{ 
[Export(typeof(DropWindowViewModel))] 
public class DropWindowViewModel : PropertyChangedBase, IHaveDisplayName 
{ 
    private readonly IWindowManager windowManager; 

    [ImportingConstructor] 
    public DropWindowViewModel(IWindowManager windowManager) 
    { 
     this.windowManager = windowManager; 
    } 

    public string DisplayName 
    { 
     get { return "Main Window"; } 
     set { } 
    }   

    public bool AlwaysOnTop 
    { 
     get { return Settings.Default.DropWindowAlwaysOnTop; } 
     set 
     { 
      Settings.Default.DropWindowAlwaysOnTop = value; 
      Settings.Default.Save(); 
      NotifyOfPropertyChange(() => AlwaysOnTop); 
      //todo: toggle the AOT attribute of the window 
     } 
    } 

    public void FileDropped(DragEventArgs eventArgs) 
    { 
     if (eventArgs.Data.GetDataPresent(DataFormats.FileDrop)) 
     { 
      string[] droppedFilePaths = eventArgs.Data.GetData(DataFormats.FileDrop, true) as string[]; 
      foreach (string path in droppedFilePaths) 
      { 
       MessageBox.Show(path); 
      } 

      windowManager.ShowWindow(new WizardViewModel()); 
     } 
    } 

} 

}

Answer 1

可以使用ShowWindow方法的settings参数与含有PROPERTYNAME - 值对的字典创建的窗口上设置的任何特性（例如Topmost）：

windowManager.ShowWindow(new WizardViewModel(), 
    settings: new Dictionary<string,object> { {"Topmost", AlwaysOnTop} }); 

如果您想更改已创建窗口的Topmost属性，我会看到三个选项（按照优先顺序）：

1. 创建于WizardViewModel的AlwaysOnTop属性和视图模型存储在私人领域，并委托AlwaysOnTop到WizardViewModel：

   private WizardViewModel wizardViewModel; 
   
   public void FileDropped(DragEventArgs eventArgs) 
   { 
       //... 
       wizardViewModel = new WizardViewModel() 
       windowManager.ShowWindow(wizardViewModel); 
   } 
   
   public bool AlwaysOnTop 
   { 
       get { return Settings.Default.DropWindowAlwaysOnTop; } 
       set 
       { 
        //... 
        if (wizardViewModel != null) 
         wizardViewModel.AlwaysOnTop = value; 
       } 
   } 
   

   而且在你看来，你可以绑定WizardViewModel的AlwaysOnTop财产到窗口的TopMost属性。

2. 您可以使用Application.Windows来检索窗口。例如。从WindowManager

   windowManager.ShowWindow(new WizardViewModel(), 
       settings: new Dictionary<string,object> 
        { {"Topmost", AlwaysOnTop}, {"Name", "WizardWindow"} }); 
   
   public bool AlwaysOnTop 
   { 
       get { return Settings.Default.DropWindowAlwaysOnTop; } 
       set 
       { 
        //... 
        var wizardViewModel = Application.Current.Windows.OfType<Window>() 
         .SingleOrDefault(w => w.Name == "WizardWindow"); 
        if (wizardViewModel != null) 
         wizardViewModel.AlwaysOnTop = value; 
       } 
   } 
   

3. 导出并在Bootstrapper注册，然后你可以重写CreateWindow，EnsureWindow等方法来存储创建的窗口：设置所创建的窗口的Name属性与设置字典，某处设置了附加属性等。