Windows 8 UserControl框架对象导航 [英] Windows 8 UserControl Frame Object Navigation

问题描述

在XAML用户控件中，Frame对象为null:

Within a XAML user control, the Frame object is null:

this.Frame.Navigate(typeof(FaxPropertiesPage));

this.Frame.Navigate(typeof(FaxPropertiesPage));

如何使用Windows 8 XAML用户控件在页面之间导航?我已将控件放置在XAML页面上的Callisto弹出窗口中.

How do I navigate between pages with a Windows 8 XAML User Control? I have placed the control within a Callisto Flyout on a XAML page.

下面的搜索按钮必须将用户导航到另一个XAML页面.

The search button below must navigate the user to another XAML page.

推荐答案

有一种不错的方法，但又不是那么好的方法:

There's the nice way and the not-so-nice way:

两者都以导航服务开头:

Both of them start with a navigation service:

public interface INavigationService
{
    bool CanGoBack { get; }
    void GoBack();
    void GoForward();
    bool Navigate<T>(object parameter = null);
    bool Navigate(Type source, object parameter = null);
    void ClearHistory();
    event EventHandler<NavigatingCancelEventArgs> Navigating;
}

public class NavigationService : INavigationService
{
    private readonly Frame _frame;

    public NavigationService(Frame frame)
    {
        _frame = frame;
        frame.Navigating += FrameNavigating;
    }

    #region INavigationService Members

    public void GoBack()
    {
        _frame.GoBack();
    }

    public void GoForward()
    {
        _frame.GoForward();
    }

    public bool Navigate<T>(object parameter = null)
    {
        Type type = typeof (T);

        return Navigate(type, parameter);
    }

那么，我在哪里可以得到相框?在App.xaml.cs

So, where do I get the Frame? In App.xaml.cs

protected async override void OnLaunched(LaunchActivatedEventArgs args)
{
    // Do not repeat app initialization when already running, just ensure that
    // the window is active
    if (args.PreviousExecutionState == ApplicationExecutionState.Running)
    {
        Window.Current.Activate();
        return;
    }

    // Create a Frame to act as the navigation context and navigate to the first page
    var rootFrame = new Frame();
    if (DesignMode.DesignModeEnabled)
        SimpleIoc.Default.Register<INavigationService, DesignTimeNavigationService>();
    else
        SimpleIoc.Default.Register<INavigationService>(() => new NavigationService(rootFrame));

我在这里使用MVVM Light.这使生活变得轻松，因为我所有的视图模型都是使用依赖项注入创建的，并将其服务注入了其中.

I'm using MVVM Light here. This makes life easy because all my viewmodels get created using dependency injection and have their services injected into them.

如果您不使用MVVM Light之类的东西，而是依靠后台代码，那么您仍然可以使这项工作有效:只需将导航服务设为静态

If you're not using something like MVVM Light and rely on code-behind then you can still make this work: Just make the navigation service static

  public class NavigationService : INavigationService
    {
        public static INavigationService Current{
get;set;}

blah blah blah
}

并将App.xaml.cs更改为:

And change App.xaml.cs to:

    protected async override void OnLaunched(LaunchActivatedEventArgs args)
    {
        // Do not repeat app initialization when already running, just ensure that
        // the window is active
        if (args.PreviousExecutionState == ApplicationExecutionState.Running)
        {
            Window.Current.Activate();
            return;
        }

        // Create a Frame to act as the navigation context and navigate to the first page
        var rootFrame = new Frame();
        NavigationService.Current= new NavigationService(rootFrame));
}

然后您可以在应用中的任何位置通过说出以下内容来访问主框架:

And you can then access your main Frame anywhere in the app by saying:

NavigationService.Current.Navigate<MyView>();

这篇关于Windows 8 UserControl框架对象导航的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！