C++ Ptr::reset方法代码示例

void Application::Run() {
	sf::RenderWindow app_window( sf::VideoMode( 800, 600 ), "SFGUI Button Example", sf::Style::Titlebar | sf::Style::Close );

	// We have to do this because we don't use SFML to draw.
	app_window.resetGLStates();

	window = sfg::Window::Create();
	window->SetTitle( "Title" );

	sfg::Box::Ptr box = sfg::Box::Create( sfg::Box::VERTICAL );
	window->Add( box );

	// Possibility 1, normal function
	sfg::Button::Ptr button1 = sfg::Button::Create();
	button1->SetLabel( "Clicky 1" );
	button1->OnLeftClick.Connect( &Foo );
	box->Pack( button1, false );

	// Possibility 2, this class
	sfg::Button::Ptr button2 = sfg::Button::Create();
	button2->SetLabel( "Clicky 2" );
	button2->OnLeftClick.Connect( &Application::Bar, this );
	box->Pack( button2, false );

	// Possibility 3, objects
	BazClass baz_array[3] = { BazClass( 1 ), BazClass( 2 ), BazClass( 3 ) };

	for( int i = 0; i < 3; i++ ) {
		std::stringstream sstr;
		sstr << "Clicky " << i + 3;
		sfg::Button::Ptr button = sfg::Button::Create();
		button->SetLabel( sstr.str() );
		// This is just a more complicated way of passing a pointer to a
		// BazClass to Connect() when the BazClass object is part of an array.
		// Passing normal pointers such as &baz1 would also work.
		button->OnLeftClick.Connect( &BazClass::Baz, &( baz_array[i] ) );
		box->Pack( button, false );
	}

	// Notice that with possibility 3 you can do very advanced things. The tricky
	// part of implementing it this way is that the method address has to be
	// known at compile time, which means that only the instanciated object itself
	// is able to pick how it will behave when that method is called on it. This
	// way you can also connect signals to dynamically determined behavior.

	// For further reading on this topic refer to Design Patterns and as
	// specialized cases similar to the one in this example the
	// Factory Method Pattern and Abstract Factory Pattern.

	while ( app_window.isOpen() ) {
		sf::Event event;

		while ( app_window.pollEvent( event ) ) {
			window->HandleEvent( event );

			if ( event.type == sf::Event::Closed ) {
				app_window.close();
			}
		}

		// Update the GUI, note that you shouldn't normally
		// pass 0 seconds to the update method.
		window->Update( 0.f );

		// Clear screen
		app_window.clear();

		// Draw the GUI
		m_sfgui.Display( app_window );

		// Update the window
		app_window.display();
	}

	// If you have any global or static widgets,
	// you need to reset their pointers before your
	// application exits.
	window.reset();
}