How to do an action when button is pressed - c++

Question

I am creating a log in screen for my app, I created the buttons but I dont know how to make my program do something when one of these buttons are pressed.Here is my code(I dont think it will be usefull)
LRESULT CALLBACK WndProc(HWND hwnd, UINT Message, WPARAM wParam, LPARAM lParam) {
switch(Message) {
case WM_CREATE:
CreateWindow(TEXT("button"), TEXT("CONFIRM"), WS_VISIBLE | WS_CHILD, 355, 400, 95, 35, hwnd, NULL, NULL , NULL);
CreateWindow(TEXT("button"), TEXT("SIGN UP"), WS_VISIBLE | WS_CHILD, 50, 400, 95, 35, hwnd, NULL, NULL, NULL);
CreateWindow(TEXT("static"), TEXT("USERNAME:"), WS_VISIBLE | WS_CHILD, 50, 40, 80, 15, hwnd, NULL, NULL, NULL);
CreateWindow(TEXT("static"), TEXT("EMAIL:"), WS_VISIBLE | WS_CHILD, 85, 100, 45, 15, hwnd, NULL, NULL, NULL);
CreateWindow(TEXT("static"), TEXT("PASSWORD:"), WS_VISIBLE | WS_CHILD, 50, 160, 83, 15, hwnd, NULL, NULL, NULL);
CreateWindow(TEXT("edit"), TEXT(""), WS_VISIBLE | WS_CHILD, 135, 40, 200, 17, hwnd, NULL, NULL, NULL);
CreateWindow(TEXT("edit"), TEXT(""), WS_VISIBLE | WS_CHILD, 135, 100, 200, 17, hwnd, NULL, NULL, NULL);
CreateWindow(TEXT("edit"), TEXT(""), WS_VISIBLE | WS_CHILD, 135, 160, 200, 17, hwnd, NULL, NULL, NULL);
break;
/* Upon destruction, tell the main thread to stop */
case WM_DESTROY: {
PostQuitMessage(0);
break;
}
/* All other messages (a lot of them) are processed using default procedures */
default:
return DefWindowProc(hwnd, Message, wParam, lParam);
}
return 0;
}
/* The 'main' function of Win32 GUI programs: this is where execution starts */
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) {
WNDCLASSEX wc; /* A properties struct of our window */
HWND hwnd; /* A 'HANDLE', hence the H, or a pointer to our window */
MSG msg; /* A temporary location for all messages */
/* zero out the struct and set the stuff we want to modify */
memset(&wc,0,sizeof(wc));
wc.cbSize = sizeof(WNDCLASSEX);
wc.lpfnWndProc = WndProc; /* This is where we will send messages to */
wc.hInstance = hInstance;
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
/* White, COLOR_WINDOW is just a #define for a system color, try Ctrl+Clicking it */
wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wc.lpszClassName = "WindowClass";
wc.hIcon = LoadIcon(NULL,"XBM LOGO.png"); /* Load a standard icon */
wc.hIconSm = LoadIcon(NULL, "A"); /* use the name "A" to use the project icon */
if(!RegisterClassEx(&wc)) {
MessageBox(NULL, "Window Registration Failed!","Error!",MB_ICONEXCLAMATION|MB_OK);
return 0;
}
hwnd = CreateWindowEx(WS_EX_CLIENTEDGE,"WindowClass","Verification",WS_VISIBLE|WS_OVERLAPPEDWINDOW,
400, /* x */
75, /* y */
500, /* width */
600, /* height */
NULL,NULL,hInstance,NULL);
if(hwnd == NULL) {
MessageBox(NULL, "Window Creation Failed!","Error!",MB_ICONEXCLAMATION|MB_OK);
return 0;
}
/*
This is the heart of our program where all input is processed and
sent to WndProc. Note that GetMessage blocks code flow until it receives something, so
this loop will not produce unreasonably high CPU usage
*/
while(GetMessage(&msg, NULL, 0, 0) > 0) { /* If no error is received... */
TranslateMessage(&msg); /* Translate key codes to chars if present */
DispatchMessage(&msg); /* Send it to WndProc */
}
return msg.wParam;
}
NOTE: windows.h and iostream are included but there are not any other libraries
Thank you :)

Answer 1

The first thing you need to change is to assign an ID to your button CreateWindow calls, this is done through the HMENU parameter. The next thing you need to do is handle WM_COMMAND for those IDs and the BN_CLICKED command identifier.
For example, to assign the ID 1 to your Confirm button:
CreateWindow(TEXT("button"), TEXT("CONFIRM"), WS_VISIBLE | WS_CHILD, 355, 400, 95, 35, hwnd, (HMENU)1, NULL, NULL);
Then to handle when that is clicked:
case WM_COMMAND:
{
UINT uID = LOWORD(wParam), uCmd = HIWORD(wParam);
switch(uID)
{
case 1:
if(BN_CLICKED == uCmd)
{
/* Action here */
break;
}
else
return DefWindowProc(hWnd, uMsg, wParam, lParam);
default:
return DefWindowProc(hWnd, uMsg, wParam, lParam);
}
}