Detect if mouse button is down - c++

Question

I am new to c++ and I am trying to activate a line of code only when the left mouse button is held down. In this example, my code works but it seems that it just toggles it. When I click, it spams the H key then, when I click again, it stops.
Currently I have this code:
if ((GetKeyState(VK_LBUTTON)))
{
keybd_event(VkKeyScan('H'),0,0,0);
Sleep ( 30 );
}
Edit:
I have inside the function:
int WINAPI WinMain ( HINSTANCE hInst, HINSTANCE P, LPSTR CMD, int nShowCmd );

Answer 1

Use this to determine if the button is pressed.
if((GetKeyState(VK_LBUTTON) & 0x8000) != 0)
http://vcpptips.wordpress.com/tag/vk_lbutton/

Answer 2

The application can catch messages and process being sent to your window indicating a state change of any mouse button.
When the left button is pressed a
WM_LBUTTONDOWN
is sent.
When it is released
WM_LBUTTONUP
is sent.
Please read here for various messages being sent to indicate mouse events.

Answer 3

Use the below to detect left mouse button press
if(GetAsyncKeyState(VK_LBUTTON)){
//your code controls here
}
You can find more controls here : https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getasynckeystate
Also if the GetAsyncKeyState(VK_LBUTTON)shows a syntax error, try including winuser.h by adding #include <winuser.h> in the includes of your code.
Here is an example
if(GetKeyState(VK_LBUTTON))
{ //finding clicked position
HWND hWnd = FindWindowA(0,("Motion Paths"));
::GetWindowThreadProcessId(hWnd,&pid);
if (hWnd) { cout << "Found" << endl;}
POINT p;
GetCursorPos(&p);
if (ScreenToClient(hWnd, &p))
{
int mouseX = p.x;
int mouseY = p.y;
cout<< p.x << " "<< p.y <<endl;
}
}

Answer 4

In first - need DEFINE BUTTON ID(or another object ID) in begin code:
#define ID_BUTTON1 105
Then AFTER creationale of hWnd - we make button:
HWND HwndButton1 = CreateWindow(
L"BUTTON", // Predefined class; Unicode assumed
L"OK", // Button text
WS_TABSTOP | WS_VISIBLE | WS_CHILD | BS_DEFPUSHBUTTON, // Styles
10, // x position
10, // y position
100, // Button width
100, // Button height
hWnd, // Parent window
(HMENU) ID_BUTTON1, // ID кнопки в меню
NULL, // Сущность мне неведомая 8-)
NULL); // Pointer not needed.
And then add trigger in function:
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
int wmId=0, wmEvent; //wmId NEED DEFINE null - if he is not available in event, else be ашипка
PAINTSTRUCT ps;
HDC hdc;
switch (message)
{
case WM_COMMAND:
wmEvent = HIWORD(wParam); // Name of EVENT - имя события
wmId = LOWORD(wParam); // ID element for event - элемент с которым оно случилось
case WM_LBUTTONDOWN: MessageBox(NULL, L"MouseL_Click", L"WndHeader", MB_OK | MB_ICONEXCLAMATION); // Left Mouse Button pressed
if( LOWORD(wParam) == 105 && WM_COMMAND == WM_LBUTTONDOWN){ // Клик по ID_BUTTON1 левым мышком
EndDialog(hWnd,0);
}
................ // Many another function
}