c# - wp8 应用程序对象

Question

我是 Windows Phone 编程的新手，我正在构建一个 WP8 应用程序，想从另一个模块访问“App”对象例如:

ModuleA = 'public partial class App : Application' 对象所在的位置

ModuleB = 'DoThis.xaml' 页面所在的位置

我在 ModuleA 中有这个:

public partial class App : Application
{
 // .. most application stuff stripped out for brevity

  private void Application_Launching(object sender, LaunchingEventArgs e)
  {
    // refresh the value of the IsTrial property when the application is launched
    DetermineIsTrial();

    string uriString = "/ModuleB;component/DoThis.xaml";
    NavigationService.Navigate(new Uri(uriString, UriKind.Relative));
  }

#region Trial
public static bool IsTrial
{
  get;
  // setting the IsTrial property from outside is not allowed
  private set;
}

private void DetermineIsTrial()
{
#if TRIAL
  // set true if trial enabled (Debug_Trial configuration is active)
  IsTrial = true;
#else
  var license = new Microsoft.Phone.Marketplace.LicenseInformation();
  IsTrial = license.IsTrial();
#endif

#if DEBUG
  // set to false if we are debugging....
  //IsTrial = false;
#endif

}

#endregion
}

我不知道如何将“App”对象从 ModuleA 转移到 ModuleB 以便我可以访问它

我想在 ModuleB 中这样做

protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
{
  Debug.WriteLine("DoThis- OnNavigatedTo");

  if( App.IsTrial )  // I would like this to be ModuleA's "App" object
  {
     // disable some functionality because trial mode...
  }

 // the rest cut for brevity 
}

感谢您的帮助!

Answer 1

您始终可以通过 Application.Current 访问 Application 对象。

在你的模块类中声明一个接口(interface):

public interface IMyApplication
{
    void DoStuffInMainApp();           
}

并在您的应用程序类中实现它:

public partial class App : Application, ModuleB.IMyApplication
{
    ...
}

现在您可以从模块中调用应用程序类中的方法:

((IMyApplication)Application.Current).DoStuffInMainApp();