root/samples/winrt/FaceDetection/FaceDetection/App.xaml.cpp

DEFINITIONS

1. OnLaunched
2. OnSuspending
3. OnNavigationFailed

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

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

using namespace FaceDetection;

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;

// The Blank Application template is documented at http://go.microsoft.com/fwlink/?LinkId=234227

/// <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="e">Details about the launch request and process.</param>
void App::OnLaunched(Windows::ApplicationModel::Activation::LaunchActivatedEventArgs^ e)
{

#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();

        // Set the default language
        rootFrame->Language = Windows::Globalization::ApplicationLanguages::Languages->GetAt(0);

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

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

        }

        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), e->Arguments);
        }
        // Place the frame in the current Window
        Window::Current->Content = rootFrame;
        // Ensure the current window is active
        Window::Current->Activate();
    }
    else
    {
        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), e->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="sender">The source of the suspend request.</param>
/// <param name="e">Details about the suspend request.</param>
void App::OnSuspending(Object^ sender, SuspendingEventArgs^ e)
{
    (void) sender;      // Unused parameter
    (void) e;   // Unused parameter

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

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