occt/samples/xaml/App.xaml.cpp

//
// App.xaml.cpp
// Implementation of the App class.
//

#include "pch.h"
#include "MainPage.xaml.h"

using namespace uwp;

using namespace Platform;
using namespace Windows::ApplicationModel;
using namespace Windows::ApplicationModel::Activation;
using namespace Windows::Foundation;
using namespace Windows::Foundation::Collections;
using namespace Windows::UI::Xaml;
using namespace Windows::UI::Xaml::Controls;
using namespace Windows::UI::Xaml::Controls::Primitives;
using namespace Windows::UI::Xaml::Data;
using namespace Windows::UI::Xaml::Input;
using namespace Windows::UI::Xaml::Interop;
using namespace Windows::UI::Xaml::Media;
using namespace Windows::UI::Xaml::Navigation;

/// <summary>
/// Initializes the singleton application object.  This is the first line of authored code
/// executed, and as such is the logical equivalent of main() or WinMain().
/// </summary>
App::App()
{
  InitializeComponent();
  Suspending += ref new SuspendingEventHandler(this, &App::OnSuspending);
}

/// <summary>
/// Invoked when the application is launched normally by the end user.  Other entry points
/// will be used such as when the application is launched to open a specific file.
/// </summary>
/// <param name="theEvent">Details about the launch request and process.</param>
void App::OnLaunched(Windows::ApplicationModel::Activation::LaunchActivatedEventArgs^ theEvent)
{
#if _DEBUG
  // Show graphics profiling information while debugging.
  if (IsDebuggerPresent())
  {
    // Display the current frame rate counters
    DebugSettings->EnableFrameRateCounter = true;
  }
#endif
  auto rootFrame = dynamic_cast<Frame^>(Window::Current->Content);

  // Do not repeat app initialization when the Window already has content,
  // just ensure that the window is active
  if (rootFrame == nullptr)
  {
    // Create a Frame to act as the navigation context and associate it with
    // a SuspensionManager key
    rootFrame = ref new Frame();

    rootFrame->NavigationFailed += ref new Windows::UI::Xaml::Navigation::NavigationFailedEventHandler(this, &App::OnNavigationFailed);

    if (theEvent->PreviousExecutionState == ApplicationExecutionState::Terminated)
    {
      // TODO: Restore the saved session state only when appropriate, scheduling the
      // final launch steps after the restore is complete

    }

    if (theEvent->PrelaunchActivated == false)
    {
      if (rootFrame->Content == nullptr)
      {
        // When the navigation stack isn't restored navigate to the first page,
        // configuring the new page by passing required information as a navigation
        // parameter
        rootFrame->Navigate(TypeName(MainPage::typeid), theEvent->Arguments);
      }
      // Place the frame in the current Window
      Window::Current->Content = rootFrame;
      // Ensure the current window is active
      Window::Current->Activate();
    }
  }
  else
  {
    if (theEvent->PrelaunchActivated == false)
    {
      if (rootFrame->Content == nullptr)
      {
        // When the navigation stack isn't restored navigate to the first page,
        // configuring the new page by passing required information as a navigation
        // parameter
        rootFrame->Navigate(TypeName(MainPage::typeid), theEvent->Arguments);
      }
      // Ensure the current window is active
      Window::Current->Activate();
    }
  }
}

/// <summary>
/// Invoked when application execution is being suspended.  Application state is saved
/// without knowing whether the application will be terminated or resumed with the contents
/// of memory still intact.
/// </summary>
/// <param name="theSender">The source of the suspend request.</param>
/// <param name="theEvent">Details about the suspend request.</param>
void App::OnSuspending(Object^ theSender, SuspendingEventArgs^ theEvent)
{
  (void)theSender;  // Unused parameter
  (void)theEvent;   // Unused parameter

                    //TODO: Save application state and stop any background activity
}

/// <summary>
/// Invoked when Navigation to a certain page fails
/// </summary>
/// <param name="theSender">The Frame which failed navigation</param>
/// <param name="theEvent">Details about the navigation failure</param>
void App::OnNavigationFailed(Platform::Object ^theSender, Windows::UI::Xaml::Navigation::NavigationFailedEventArgs ^theEvent)
{
  throw ref new FailureException("Failed to load Page " + theEvent->SourcePageType.Name);
}