如何从viewmodel(Caliburn + WPF)关闭对话框窗口？

Question

我ViewModel1和View1相关联.我ViewModel2使用IWindowManagerobject 从(另一个viewmodel)启动对话框窗口.ViewModel2类中的代码:

windowManager.ShowDialog(new ViewModel());

所以,我有Viewop窗口和View1用户控件.

我的答案是下一个 - 我可以使用红色关闭按钮关闭该对话框窗口,但是如何使用我的特定按钮(包含在View1用户控件中)关闭它,类似"取消"按钮和关闭命令(Command={Binding CancelCommand}),CancelCommand当然包含在ViewModel1课堂上.

Answer 1

如果您的视图模型扩展,它会更容易Caliburn.Micro.Screen:

TryClose();

Answer 2

您可以通过在IViewAwareViewModel上实现接口来获取当前视图(在您的情况下是对话框窗口).然后,您可以Close在Window执行命令时调用视图(创建为对话框).

最简单的原因是ViewAware:

public class DialogViewModel : ViewAware
{
    public void ExecuteCancelCommand()
    {
        (GetView() as Window).Close();
    }
}

如果您不被允许派生,您可以自己实施:

public class DialogViewModel : IViewAware
{
    public void ExecuteCancelCommand()
    {
        dialogWindow.Close();
    }

    private Window dialogWindow;
    public void AttachView(object view, object context = null)
    {
        dialogWindow = view as Window;
        if (ViewAttached != null)
            ViewAttached(this, 
               new ViewAttachedEventArgs(){Context = context, View = view});
    }

    public object GetView(object context = null)
    {
        return dialogWindow;
    }

    public event EventHandler<ViewAttachedEventArgs> ViewAttached;
}

注意:我已经使用Caliburn.Micro 1.3.1作为我的样本.

Answer 3

我使用的一种更清洁的方式(个人品味的主题)是使用IResult模式,这样你抽象Window实现

视图模型

public IEnumerable<IResult> CloseMe()
{
    yield return new CloseResult();
}

结果代码

public class CloseResult : Result
{
    public override void Execute(ActionExecutionContext context)
    {
        var window = Window.GetWindow(context.View);
        window.Close();            

        base.Execute(context);
    }
}

public abstract class Result : IResult
{
    public virtual void Execute(ActionExecutionContext context)
    {
        OnCompleted(this, new ResultCompletionEventArgs());
    }

    protected virtual void OnCompleted(object sender, ResultCompletionEventArgs e)
    {
        if (Completed != null)
            Completed(sender, e);
    }

    public event EventHandler<ResultCompletionEventArgs> Completed;
}

编辑(仅适用于IoC):如果您想更进一步,请为所有屏幕执行基类

public abstract class ShellPresentationModel : Screen
{
    public ShellPresentationModel(IResultFactory resultFactory)
    {
        Result = resultFactory;
    }

    public IResultFactory Result { get; private set; }
}

通过这种方式,您可以更轻松地为IoC注入依赖关系,然后您的VIewmodel close方法将如下所示

public IEnumerable<IResult> CloseMe()
{
    yield return Result.Close();
}

关于使用依赖的IResult的示例可以是

public class ShowDialogResult<TModel> : Result
{
    private readonly IWindowManager windowManager;
    private readonly TModel model;
    private Action<TModel> configure;

    public ShowDialogResult(IWindowManager windowManager, TModel model)
    {
        this.windowManager = windowManager;
        this.model = model;
    }

    public IResult Configure(Action<TModel> configure)
    {
       this.configure = configure;
       return this;
    }

    public override void Execute(ActionExecutionContext context)
    {
        if(configure != null)
            configure(model);

        windowManager.ShowDialog(model);

        base.Execute(context);
    }
}

编辑只是注意到我忘了添加上面的IoC exmaple示例,这里有一个子IoC容器模式,它看起来像这样

public IEnumerable<IResult> ShowDialog()
{
    yield return Result.ShowDialog<MyViewModel>();
}

如果没有子容器模式,则需要手动将父依赖同步注入子进程

    yield return Result.ShowDialog<MyViewModel>().Configure(m => m.SomeData = this.SomeData);