calling a function from a button

[MPrestonf12]

I've tried to call a function from a button on a window. But nothing happens. I am calling it as I would in a console app but that's not working. How do you call it from a button? thanks

[SteveCRM]

It should work...post your code.

[MPrestonf12]

#include <windows.h>

HWND ghWnd_button1;
HWND hwnd; /* This is the handle for our window */

/* Declare Windows procedure */
LRESULT CALLBACK WindowProcedure(HWND, UINT, WPARAM, LPARAM);
/* Make the class name into a global variable */
char szClassName[ ] = "WindowsApp";
int WINAPI WinMain(HINSTANCE hThisInstance, HINSTANCE hPrevInstance, LPSTR lpszArgument, int nFunsterStil)

{

MSG messages; /* Here messages to the application are saved */
WNDCLASSEX wincl; /* Data structure for the windowclass */

/* The Window structure */
wincl.hInstance = hThisInstance;
wincl.lpszClassName = szClassName;
wincl.lpfnWndProc = WindowProcedure; /* This function is called by windows */
wincl.style = CS_DBLCLKS; /* Catch double-clicks */
wincl.cbSize = sizeof(WNDCLASSEX);

/* Use default icon and mouse-pointer */
wincl.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wincl.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
wincl.hCursor = LoadCursor(NULL, IDC_ARROW);
wincl.lpszMenuName = NULL; /* No menu */
wincl.cbClsExtra = 0; /* No extra bytes after the window class */
wincl.cbWndExtra = 0; /* structure or the window instance */
/* Use light-gray as the background of the window */
wincl.hbrBackground = (HBRUSH) GetStockObject(LTGRAY_BRUSH);

/* Register the window class, if fail quit the program */
if(!RegisterClassEx(&wincl)) return 0;

/* The class is registered, let's create the program*/
hwnd = CreateWindowEx(
0, /* Extended possibilites for variation */
szClassName, /* Classname */
"Windows App", /* Title Text */
WS_OVERLAPPEDWINDOW, /* default window */
CW_USEDEFAULT, /* Windows decides the position */
CW_USEDEFAULT, /* where the window ends up on the screen */
544, /* The programs width */
375, /* and height in pixels */
HWND_DESKTOP, /* The window is a child-window to desktop */
NULL, /* No menu */
hThisInstance, /* Program Instance handler */
NULL /* No Window Creation data */
);

ghWnd_button1 = CreateWindow("Button", "Button 1", \
WS_CHILD | WS_VISIBLE, \
50, 50, 200, 40,hwnd, NULL, hThisInstance, NULL);

/* Make ULL,hThisInstance,Nthe window visible on the screen */
ShowWindow(hwnd, nFunsterStil);
/* Run the message loop. It will run until GetMessage( ) returns 0 */
while(GetMessage(&messages, NULL, 0, 0))
{
/* Translate virtual-key messages into character messages */
TranslateMessage(&messages);
/* Send message to WindowProcedure */
DispatchMessage(&messages);
}

/* The program return-value is 0 - The value that PostQuitMessage( ) gave */
return messages.wParam;
}

/* This function is called by the Windows function DispatchMessage( ) */
LRESULT CALLBACK WindowProcedure(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message) /* handle the messages */
{ case WM_COMMAND:
if(LOWORD(wParam) == BN_CLICKED && (HWND)lParam == ghWnd_button1) {
int space(5);
}
case WM_DESTROY:
PostQuitMessage(0); /* send a WM_QUIT to the message queue */
break;
default: /* for messages that we don't deal with */
return DefWindowProc(hwnd, message, wParam, lParam);
}
return 0;
}

int test(int i)
{
MessageBox(hwnd,i, "My Messagebox", MB_OK);
return 0;
}

[SteveCRM]

First of all...I don't see a prototype. Next, in your button you say int space(5), but you only have the function

int test(int i)

[MPrestonf12]

ok, i think i corrected it but still nothing. Here is the corrected code(not functioning).

#include <windows.h>
#include <stdlib.h>
#include <iostream>

int test();

HWND ghWnd_button1;
HWND hwnd; /* This is the handle for our window */

/* Declare Windows procedure */
LRESULT CALLBACK WindowProcedure(HWND, UINT, WPARAM, LPARAM);
/* Make the class name into a global variable */
char szClassName[ ] = "WindowsApp";
int WINAPI WinMain(HINSTANCE hThisInstance, HINSTANCE hPrevInstance, LPSTR lpszArgument, int nFunsterStil)

{
MSG messages; /* Here messages to the application are saved */
WNDCLASSEX wincl; /* Data structure for the windowclass */

/* The Window structure */
wincl.hInstance = hThisInstance;
wincl.lpszClassName = szClassName;
wincl.lpfnWndProc = WindowProcedure; /* This function is called by windows */
wincl.style = CS_DBLCLKS; /* Catch double-clicks */
wincl.cbSize = sizeof(WNDCLASSEX);

/* Use default icon and mouse-pointer */
wincl.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wincl.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
wincl.hCursor = LoadCursor(NULL, IDC_ARROW);
wincl.lpszMenuName = NULL; /* No menu */
wincl.cbClsExtra = 0; /* No extra bytes after the window class */
wincl.cbWndExtra = 0; /* structure or the window instance */
/* Use light-gray as the background of the window */
wincl.hbrBackground = (HBRUSH) GetStockObject(LTGRAY_BRUSH);

/* Register the window class, if fail quit the program */
if(!RegisterClassEx(&wincl)) return 0;

/* The class is registered, let's create the program*/
hwnd = CreateWindowEx(
0, /* Extended possibilites for variation */
szClassName, /* Classname */
"Windows App", /* Title Text */
WS_OVERLAPPEDWINDOW, /* default window */
CW_USEDEFAULT, /* Windows decides the position */
CW_USEDEFAULT, /* where the window ends up on the screen */
544, /* The programs width */
375, /* and height in pixels */
HWND_DESKTOP, /* The window is a child-window to desktop */
NULL, /* No menu */
hThisInstance, /* Program Instance handler */
NULL /* No Window Creation data */
);

ghWnd_button1 = CreateWindow("Button", "Button 1", \
WS_CHILD | WS_VISIBLE, \
50, 50, 200, 40,hwnd, NULL, hThisInstance, NULL);

/* Make ULL,hThisInstance,Nthe window visible on the screen */
ShowWindow(hwnd, nFunsterStil);
/* Run the message loop. It will run until GetMessage( ) returns 0 */
while(GetMessage(&messages, NULL, 0, 0))
{
/* Translate virtual-key messages into character messages */
TranslateMessage(&messages);
/* Send message to WindowProcedure */
DispatchMessage(&messages);
}

/* The program return-value is 0 - The value that PostQuitMessage( ) gave */
return messages.wParam;
}

/* This function is called by the Windows function DispatchMessage( ) */
LRESULT CALLBACK WindowProcedure(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message)
/* handle the messages */

{
case WM_COMMAND:
if(LOWORD(wParam) == BN_CLICKED && (HWND)lParam == ghWnd_button1)
int test();
//When it gets here if i use break it does it exits with no messagebox. If i don't it just does not seem to exacute the function.
case WM_DESTROY:
PostQuitMessage(0); /* send a WM_QUIT to the message queue */
break;
default: /* for messages that we don't deal with */
return DefWindowProc(hwnd, message, wParam, lParam);
}
return 0;
}

int test()
{
MessageBox (NULL, "hello" , "hello", 0);
return 0;
}


I appreciate your help. Im still pretty new at this.

[parksie]

case WM_COMMAND:
if(LOWORD(wParam) == BN_CLICKED && (HWND)lParam == ghWnd_button1)
test();
break;

You don't need to redefine anything else.