自学教程：C++ IsKeyDown函数代码示例

// Player movement behaviour and controls //void Player::Move(int screenX, int screenY){	if(IsKeyDown(KEY_UP) && y > height/2)	{		MoveY(-1.4);	}	else if(IsKeyDown(KEY_DOWN) && y < screenY-height/2)	{		MoveY(1.4);	}	if(IsKeyDown(KEY_LEFT) && x > width/2)	{		state = 3;		MoveX(-1.4);	}	else if(IsKeyDown(KEY_RIGHT) && x < screenX-width/2)	{		state = 4;		MoveX(1.4);	}	else		state = 0;	UpdatePosition();}

//-----------------------------------------------------voidnsNativeDragTarget::DispatchDragDropEvent(PRUint32 aEventType, POINTL aPT){  nsEventStatus status;  nsDragEvent event(PR_TRUE, aEventType, mWindow);  nsWindow * win = static_cast<nsWindow *>(mWindow);  win->InitEvent(event);  POINT cpos;  cpos.x = aPT.x;  cpos.y = aPT.y;  if (mHWnd != NULL) {    ::ScreenToClient(mHWnd, &cpos);    event.refPoint.x = cpos.x;    event.refPoint.y = cpos.y;  } else {    event.refPoint.x = 0;    event.refPoint.y = 0;  }  event.isShift   = IsKeyDown(NS_VK_SHIFT);  event.isControl = IsKeyDown(NS_VK_CONTROL);  event.isMeta    = PR_FALSE;  event.isAlt     = IsKeyDown(NS_VK_ALT);  mWindow->DispatchEvent(&event, status);}

bool nuiMatrixView::MouseMoved(nuiSize X, nuiSize Y){  if (!mClicked || !mCanChange)    return false;  nuiSize deltaX = X - mClickPos[0];  nuiSize deltaY = mClickPos[1] - Y;  mClickPos[0] = X;  mClickPos[1] = Y;    nuiSize delta = (abs(deltaX) > abs(deltaY))? deltaX : deltaY;  // fine change  if (IsKeyDown(mFineSensitivityKey))    delta = (delta > 0)? 1 : (-1);  // look at the selection  if (mSelectedItems.size() >0)  {    if (IsKeyDown(mRelativeKey))      RelativeSpinCells(delta);    else      SpinCells(delta);    return true;  }    // no selection. change the currently clicked item  mClickedItem->SetRelativeValue(delta);    return true;}

XMFLOAT2 Input::GetLookVector() const{    float x = 0.0f;    float y = 0.0f;    GetRightThumbStickValue(&x, &y);    if (IsKeyDown(VK_RIGHT))    {        x = 1.0f;    }    if (IsKeyDown(VK_LEFT))    {        x = -1.0f;    }    if (IsKeyDown(VK_UP))    {        y = 1.0f;    }    if (IsKeyDown(VK_DOWN))    {        y = -1.0f;    }    return XMFLOAT2(x, y);}

void PathFindApp::OnMouseMove(float X, float Y){	if (this->IsLeftButtonDown() && !IsKeyDown(HK_LCONTROL) && !IsKeyDown(HK_RCONTROL)) 	{		m_map.Set(X,Y,this->IsShiftKeyDown() ? 1:0);	}}

XMFLOAT2 Input::GetMovementVector() const{    float x = 0.0f;    float y = 0.0f;    GetLeftThumbStickValue(&x, &y);    if (IsKeyDown('D'))    {        x = 1.0f;    }    if (IsKeyDown('A'))    {        x = -1.0f;    }    if (IsKeyDown('W'))    {        y = 1.0f;    }    if (IsKeyDown('S'))    {        y = -1.0f;    }    return XMFLOAT2(x, y);}

// checks if score is greater than zero to decide winner //void WinLose(int &redScore, int &blueScore, bool &winLose, bool &quit){	static char cWinText[128] = {'/n'};	static char cOptionsText[128] = {'/n'};	if(redScore >= 5)	{		winLose = true;		sprintf_s(cWinText, "You Won! Play again?");		sprintf_s(cOptionsText, "Y / N");		DrawString(cWinText, 520, 300, SColour(0,255,0,255));		DrawString(cOptionsText, 620, 345, SColour(0,255,0,255));	}	else if(blueScore >= 5)	{		winLose = true;		sprintf_s(cWinText, "You Lost.. Play again?");		sprintf_s(cOptionsText, "Y / N");		DrawString(cWinText, 520, 300, SColour(0,255,0,255));		DrawString(cOptionsText, 620, 345, SColour(0,255,0,255));	}	if(IsKeyDown('Y'))	{		winLose = false;		redScore = 0;		blueScore = 0;	}	else if(IsKeyDown('N'))	{		quit = true;	}}

// menu state draws screen and checks for a key command //void UpdateMenu(bool &play, bool &quit){	DrawSprite(menu);	if(IsKeyDown(294))		play = true;	if(IsKeyDown('Q'))		quit = true;}

void PathFindApp::OnLeftButtonUp(){	if (IsKeyDown(HK_LCONTROL))		m_from.Set(GetMouseX(),GetMouseY());	else if (IsKeyDown(HK_RCONTROL)) 		m_to.Set(GetMouseX(),GetMouseY());	else		m_map.Set(GetMouseX(),GetMouseY(),this->IsShiftKeyDown() ? 1:0);}

STATE StateTemp::Update(){	SmartPointer<PacketAddr> pAddr; 	m_pNetworkControl->ReceivePacket();	ISceneManager * smgr = Irrdevice::GetInstance()->GetSceneManager(); 	if((pAddr= m_pNetworkControl->GetPacket()) != NULL) 	{ 		ServerPacketParsing(pAddr.getPoint()); 	}	if(IsKeyDown(irr::KEY_KEY_T))	{		smgr->setActiveCamera(m_pCamera);	}	if(IsKeyDown(irr::KEY_KEY_H))	{		m_pMe->SetActiveCamera();	}	if(IsKeyDown(irr::KEY_KEY_N))	{		m_pYou->SetActiveCamera();	}	// 	if(IsKeyDown(irr::KEY_KEY_T))// 	{// 		Packet p(BASE_ACK,m_MyId);	// 		p<<1;// 		m_pNetworkControl->SendClientToPacket(p);// 	}// 	if(IsKeyDown(irr::KEY_KEY_F))// 	{// 		Packet p(BASE_ACK,m_MyId);	// 		p<<2;// 		m_pNetworkControl->SendClientToPacket(p);// 	}// 	if(IsKeyDown(irr::KEY_KEY_G))// 	{// 		Packet p(BASE_ACK,m_MyId);	// 		p<<3;// 		m_pNetworkControl->SendClientToPacket(p);// 	}// 	if(IsKeyDown(irr::KEY_KEY_H))// 	{// 		Packet p(BASE_ACK,m_MyId);	// 		p<<4;// 		m_pNetworkControl->SendClientToPacket(p);// 	}	return STATE_NONE;}

// Update game (one frame)void UpdateGame(void){    if (!gameOver)    {        if (IsKeyPressed('P')) pause = !pause;        if (!pause)        {            // Player movement            if (IsKeyDown(KEY_LEFT)) player.position.x -= 5;            if ((player.position.x - player.size.x/2) <= 0) player.position.x = player.size.x/2;            if (IsKeyDown(KEY_RIGHT)) player.position.x += 5;            if ((player.position.x + player.size.x/2) >= screenWidth) player.position.x = screenWidth - player.size.x/2;            // Launch ball            if (!ball.active)            {                if (IsKeyPressed(KEY_SPACE))                {                    ball.active = true;                    ball.speed = (Vector2){ 0, -5 };                }            }                        UpdateBall();            // Game over logic            if (player.life <= 0) gameOver = true;            else            {                gameOver = true;                                for (int i = 0; i < LINES_OF_BRICKS; i++)                {                    for (int j = 0; j < BRICKS_PER_LINE; j++)                    {                        if (brick[i][j].active) gameOver = false;                    }                }            }        }    }    else    {        if (IsKeyPressed(KEY_ENTER))        {            InitGame();            gameOver = false;        }    }    }

void IntroState::HandleEvents(GameEngine* a_opGame){	// look for key presses to quit or go to the menu??	if (IsKeyDown(GLFW_KEY_ENTER))	{		a_opGame->ChangeState(PlayState::Instance());	}	if (IsKeyDown('Q'))	{		a_opGame->Quit();	}}

void get_button_state(bool *a, bool *b, bool *up, bool *down, bool *l, bool *r){	KeyInputConfig *keyConf = config->get_key_config();	if (a) *a = IsKeyJustUp(KeyConfig::KEY_MENU_SELECT) || IsControllerButtonJustUp(KeyConfig::KEY_MENU_SELECT);	if (b) *b = IsKeyJustUp(KeyConfig::KEY_MENU_BACK) || IsControllerButtonJustUp(KeyConfig::KEY_MENU_BACK);	if (up) *up = IsKeyDown(KeyConfig::KEY_MENU_UP) || IsControllerButtonDown(KeyConfig::KEY_MENU_UP);	if (down) *down = IsKeyDown(KeyConfig::KEY_MENU_DOWN) || IsControllerButtonDown(KeyConfig::KEY_MENU_DOWN);	if (r) *r = IsKeyDown(KeyConfig::KEY_MENU_RIGHT) || IsControllerButtonDown(KeyConfig::KEY_MENU_RIGHT);	if (l) *l = IsKeyDown(KeyConfig::KEY_MENU_LEFT) || IsControllerButtonDown(KeyConfig::KEY_MENU_LEFT);}

    static void SetTransform (const NewtonBody* body, const dFloat* matrix, int threadId)    {        NewtonUserJoint* player;        PlayerController* controller;        // find the player joint;        player = NULL;        for (NewtonJoint* joint = NewtonBodyGetFirstJoint(body); joint; joint = NewtonBodyGetNextJoint(body, joint)) {            NewtonUserJoint* tmp;            tmp = (NewtonUserJoint*) NewtonJointGetUserData(joint);            if (CustomGetJointID (tmp) == PLAYER_JOINT_ID) {                player = tmp;                break;            }        }        // call the generic transform callback        controller = (PlayerController*) CustomGetUserData(player);#if 1        // this will project the visual mesh to the ground        dMatrix visualMatrix;        CustomPlayerControllerGetVisualMaTrix (player, &visualMatrix[0][0]);#else        // this will display the player at the collision shape position        const dMatrix& visualMatrix = *((dMatrix*) matrix);#endif        controller->m_setTransformOriginal (body, &visualMatrix[0][0], threadId);        // now we will set the camera to follow the player        dVector eyePoint (visualMatrix.TransformVector(controller->m_point));        // check if the player wants third person view        static int prevCKeyDown = IsKeyDown  ('C');        int isCkeyDwon = IsKeyDown  ('C');        if (isCkeyDwon && !prevCKeyDown) {            controller->m_isThirdView = !controller->m_isThirdView;        }        prevCKeyDown = isCkeyDwon;        if (controller->m_isThirdView) {            dVector dir (GetCameraDir ());            eyePoint -= dir.Scale (8.0f);        }        SetCameraEyePoint (eyePoint);//		NewtonBodyGetMatrix (body, &matrix[0][0]);//		cameraEyepoint = matrix.m_posit;//		cameraEyepoint.m_y += 1.0f;    }

void ProcessInput(Game_Input *input){	input->UP.KeyDown = IsKeyDown(&Keys, input->UP.Button);	input->UP.KeyUp = IsKeyUp(&Keys, input->UP.Button);	input->DOWN.KeyDown = IsKeyDown(&Keys, input->DOWN.Button);	input->DOWN.KeyUp = IsKeyUp(&Keys, input->DOWN.Button);	input->RIGHT.KeyDown = IsKeyDown(&Keys, input->RIGHT.Button);	input->RIGHT.KeyUp = IsKeyUp(&Keys, input->RIGHT.Button);	input->LEFT.KeyDown = IsKeyDown(&Keys, input->LEFT.Button);	input->LEFT.KeyUp = IsKeyUp(&Keys, input->LEFT.Button);}

	void CPlayerController::ProcessKeys(void)	{		DIRECTION tDir = m_player->GetDirection();		b2Vec2 speed(0,0);		if (IsKeyDown(ALLEGRO_KEY_D) && !IsKeyDown(ALLEGRO_KEY_A))		{			speed.x += 5;			tDir = RIGHT;		}		else if (IsKeyDown(ALLEGRO_KEY_A) && !IsKeyDown(ALLEGRO_KEY_D))		{			speed.x -= 5;			tDir = LEFT;		}		if (IsKeyDown(ALLEGRO_KEY_W) && !IsKeyDown(ALLEGRO_KEY_S))		{			speed.y -= 5;			tDir = UP;		}		else if (IsKeyDown(ALLEGRO_KEY_S) && !IsKeyDown(ALLEGRO_KEY_W))		{			speed.y += 5;			tDir = DOWN;		}		m_player->SetSpeed(speed);		m_player->SetDirection(tDir);	}

bool InputHandler::IsKeyDown(int key, int modifiers){	if (!IsKeyDown(key))		return false;	if ((modifiers & 1) != 0 && !IsKeyDown(0x11)) // Ctrl		return false;	if ((modifiers & 2) != 0 && !IsKeyDown(0x10)) // Shift		return false;	if ((modifiers & 4) != 0 && !IsKeyDown(0x12)) // Alt		return false;	return true;}

void Update(){	// Calculate delta time	clock_t clockNow = clock();	clock_t deltaClock = clockNow - clockLastFrame;	float deltaTime = float(deltaClock) / CLOCKS_PER_SEC;	clockLastFrame = clockNow;	// Calculate FPS	framesCounter++;	framesTimeCounter += deltaTime;	if( framesTimeCounter >= 1.0 )	{		framesTimeCounter -= 1.0;		fps = framesCounter;		framesCounter = 0;	}	// Hero control	if( IsKeyDown(VK_UP) )		unitsData[heroIndex].yOrder = UnitOrder_Backward;	else		unitsData[heroIndex].yOrder = UnitOrder_None;	if( IsKeyDown(VK_LEFT) )		unitsData[heroIndex].xOrder = UnitOrder_Backward;	else	{		if( IsKeyDown(VK_RIGHT) )			unitsData[heroIndex].xOrder = UnitOrder_Forward;		else			unitsData[heroIndex].xOrder = UnitOrder_None;	}	// Update all units	for( int u = 0; u < unitsCount; u++ )		UpdateUnit( &unitsData[u], deltaTime );	// Update AI	UpdateAI();	// Hero dead	if( unitsData[heroIndex].health <= 0 )		Initialize();}

void Player::Control(){	WeaponManager();	SetSpeed(c_v2DStill);	if(IsKeyDown('A'))		SetSpeedX(-1.0f);	if(IsKeyDown('D'))		SetSpeedX(1.0f);	if(IsKeyDown('W'))		SetSpeedY(-1.0f);	if(IsKeyDown('S'))		SetSpeedY(1.0f);}

void OnUpdate(float dt){	if (IsKeyDown('W')) walk(30 * dt);	else if (IsKeyDown('S')) walk(-30 * dt);	if (IsKeyDown('A')) strafe(30 * dt);	else if (IsKeyDown('D')) strafe(-30 * dt);	float calcedX = GetMouseX() - lastMouseX, calcedY = GetMouseY() - lastMouseY;	lastMouseX = GetMouseX();	lastMouseY = GetMouseY();	if (calcedY < 0) pitch(0.5f * dt * abs(calcedY));	else if (calcedY > 0) pitch(-0.5f * dt * abs(calcedY));	if (calcedX > 0) yaw(0.5f * dt * abs(calcedX));	else if (calcedX < 0) yaw(-0.5f * dt * abs(calcedX));}

void CKeyEdit::OnKeyDown( UINT nChar, UINT /*nRepCnt*/, UINT /*nFlags*/ ) {	//debug( _T("OnKeyDown: nChar=%u nRepCnt=%u nFlags=%08x/n"), nChar, nRepCnt, nFlags );	if ( IsKeyDown( VK_MENU ) ) {		return;	}	if ( IsKeyDown( VK_CONTROL ) ) {		return;	}	if ( ! KEY_XALNUM( nChar ) )		return;	m_dwVk = (DWORD) nChar | ( IsKeyDown( VK_SHIFT ) ? 0x80000000UL : 0UL );	_Update( );}

void Player::Update(float a_dt){	m_fTimer += a_dt; // Why are we incrementing m_fTimer? To set a bullet fire rate	if (IsKeyDown('A')) m_x -= m_speed * a_dt;		if (IsKeyDown('D')) m_x += m_speed * a_dt;	if (IsKeyDown('W')) m_y -= m_speed * a_dt;	if (IsKeyDown('S')) m_y += m_speed * a_dt;	if (IsKeyDown(' ')) Fire();	// Check tos ee if we hit a boundary, this is concise- but if you expand	// it a little bit, it doesn't look much different from what you have done already	if (m_x <   0 + (m_pad + m_w2)) m_x =   0 + (m_pad + m_w2);	if (m_x > g_w - (m_pad + m_w2)) m_x = g_w - (m_pad + m_w2);}

// Received Mouse events:bool nuiKnob::MouseClicked(nuiSize X, nuiSize Y, nglMouseInfo::Flags Button){  mClickX = X;  mClickY = Y;  if ((Button & nglMouseInfo::ButtonLeft) && (Button & nglMouseInfo::ButtonDoubleClick))  {    return false;  }  else if (Button & nglMouseInfo::ButtonLeft)  {    mClicked = true;    Grab();    Invalidate();    mClickValue = mRange.GetValue();        return true;  }  else if (Button & nglMouseInfo::ButtonWheelUp)  {    if (IsKeyDown(mFineSensitivityKey))    {      mRange.SetValue(mRange.GetValue() + mRange.GetIncrement() / mFineSensitivityRatio);    }    else    {      mRange.Increment();    }    InteractiveValueChanged();    ActivateToolTip(this, true);    return true;  }  else if (Button & nglMouseInfo::ButtonWheelDown)  {    if (IsKeyDown(mFineSensitivityKey))    {      mRange.SetValue(mRange.GetValue() - mRange.GetIncrement() / mFineSensitivityRatio);    }    else    {      mRange.Decrement();    }    InteractiveValueChanged();    ActivateToolTip(this, true);    return true;  }  return false;}            

	void Input::OnKeyPressedMsgApply(KeyboardKey key)	{		if (IsKeyDown(key) || IsKeyPressed(key))			return;		mPressedKeys.Add(key);	}

	char CInputManager::GetChar(bool enableShift, bool enableCapslock) const	{		BYTE input[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'Q', 'W', 'E', 'R', 'T',			'Y', 'U', 'I', 'O', 'P', 'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L',			'Z', 'X', 'C', 'V', 'B', 'N', 'M', 0xc0, 0xbd, 0xbb, 0xdc, 0xdb,			0xdd, 0xba, 0xde, 0xbc, 0xbe, 0xbf,			' ', 0x0d, '/t', '/b' };		BYTE output[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'q', 'w', 'e', 'r', 't',			'y', 'u', 'i', 'o', 'p', 'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l',			'z', 'x', 'c', 'v', 'b', 'n', 'm', '`', '-', '=', '//', '[', ']', ';', '/'', ',', '.', '/',			' ', '/n', '/t', '/b' };		BYTE output2[] = { ')', '!', '@', '#', '$', '%', '^', '&', '*', '(', 'Q', 'W', 'E', 'R', 'T',			'Y', 'U', 'I', 'O', 'P', 'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L',			'Z', 'X', 'C', 'V', 'B', 'N', 'M', '~', '_', '+', '|', '{', '}', ':', '/"', '<', '>', '?',			' ', '/n', '/t', '/b' };		// from combination of capslock and shit, figure out what is the case		char mod = (enableShift && IsKeyDown(Keys::Shift)) + (enableCapslock && IsCapslockActive());		for (int i = 0; i < sizeof(input); i++)		{			if (IsKeyPressed((Keys)input[i]))			{				if (mod == 1)					return output2[i];				else					return output[i];			}		}		return 0;	}

void HermiteSpline::HandleUI(StateManager* stateMan){	if (IsKeyDown('M'))	{		stateMan->PopState();		return;	}	if (GetMouseButtonDown(MOUSE_BUTTON_1))	{		//loop through objects and see if clicked		for (Sprite* object : objectList)		{			if (object->ID == objectList[0]->ID)			{				double mousePosX = 0.0;				double mousePosY = 0.0;				GetMouseLocation(mousePosX, mousePosY);				mousePosY = screenHeight - mousePosY;				//std::cout << "x: " << mousePosX << " y: " << mousePosY << std::endl;				bool isCollided = object->IsCollided(Vector2(mousePosX, mousePosY));				//std::cout << "object: " << object->name << " clicked: " << isCollided << std::endl;				if (object->IsCollided(Vector2(mousePosX, mousePosY)))				{					object->position = Vector2(mousePosX, mousePosY);				}			}		}	}}

// movement code used to position the red paddle //void PaddleMovement(DynamObject &obj){	if(IsKeyDown('W') && obj.position.y > 0)	{	obj.position.y -= 1.1f;	}	else if(IsKeyDown('S') && obj.position.y < 652)	{		obj.position.y += 1.1f;	}		MoveSprite(obj.sprite, obj.position.x, obj.position.y);}

void Player::Control(){	SetSpeed(0,0);		if(IsKeyDown('A'))		SetSpeedX(-1.0f);	if(IsKeyDown('D'))		SetSpeedX(1.0f);	if(IsKeyDown('W'))		SetSpeedY(-1.0f);	if(IsKeyDown('S'))		SetSpeedY(1.0f);	if(IsKeyDown('T'))		Shoot();}

void enter(bool &bSplashActive){	if (IsKeyDown(32))	{		bSplashActive = false;	}}