Need someone to check my windows-based application code

[SomeAmazingGuy]

I think I just finished writing my first windows-based application and i was wondering if anyone can find any errors on my code. I want to make an application window and i want to make sure that my code can properly do that. If you think I am missing something crucial to create an application window, please tell me!

(p.s.. Should i copy the code to a notepad file and save it as a .exe to create the application window?)


Anyway, here is my code, so far I have created a parent window and a child window with their procedure.

#include <windows.h>
#define FirstChild 100      //child window

HINSTANCE handle;                   //handle associated with a window
HWND mainWIN;                       //handle to the main window

mainWIN = CreateWindowEX (
        0,                          //No extended styles
        "Main Class",               //The name of the window class
        "My Awesome Window",        //the name of the window itself
        WS_OVERLAPPEDWINDOW |       //Style of the window
        WS_HSCROLL | WS_VSCROLL,
        CW_USEDEFAULT,              //default horizontal position
        CW_USEDEFAULT,              //default vertical position
        CW_USEDEFAULT,              //default width
        CW_USEDEFAULT,              //default height
        (HWND) NULL,                //no parent of owner window
        (HMENU) NULL,               //use window menu
        hinstance,                  //instance handle
        null);                      //no window creation data



if (!mainWIN)                       //checking to see if theres any problems with handle to main window
    return false;


 ShowWindow (mainWIN, SW_SHOWDEFAULT);  //displays the window
 UpdateWindow (mainWIN);







//creating child window for client space in main windows

long APIENTRY MainWindowsProcedure (HWND handle, UINT message, WPARAM w, LPARAM l)
{
    RECT coordinates_of_client;                //object that contains the corner coordinates


    switch (message)
    {
        case WM_CREATE:         //creating main window

            CreateWindowEX                  //creating child window
            (
             0,                             //no extended styles
             "Child Class",                 //name of child window class
             (LPCTSTR) NULL,                //child window will not have a name
             WS_CHILD | WS_BORDER,          //specifying the style of the window
             0,0,0,0,                       //no scrolls or height or width on child window
             handle,                        //specifying parent window for this child window
             (HMENU) (int) (FirstChild)     //menu for child window (consists of child menu identifier)
             NULL                           //no windows creation data
            );
            return 0;

        case WM_SIZE:                       //main window size

            GetClientRect (handle, &coordinates_of_client); 
            EnumChildWindows (handle, EnumChildProc, (LPARAM)& coordinates_of_client);  
            return 0;
    }

    return DefWindowProc (handle, message, w,l)   //defining windows procedure
}

[freddie1]

I don't see where you've called RegisterClassEx() to register your ""Main Class".

Also, I don't understand your comment about saving the code to an exe file.

[SomeAmazingGuy]

OK i re-did most of my code and i filled out all the members of the wndclassex structure so that i can define my class. and of course i called the RegisterClassEx() function

BTW, Do you think that my code is enough to make a simple windows application?? or am i missing something else? (i'm just trying to make my first windows application)

Here is my updated code

#include <windows.h>
#define FirstChild 100              //child window

HINSTANCE handle;                   //handle associated with a window
HWND mainWIN;                       //handle to the main window

//prototype
long APIENTRY Windows_Procedure (HWND , UINT , WPARAM , LPARAM );



bool registering_class (HINSTANCE handle_to_win_procedure)
{
    WNDCLASSEX mynewclass;                              //declaring structure object
    
    mynewclass.cbSize = sizeof (mynewclass);            //giving the size of class
    mynewclass.style = CS_HREDRAW | CS_VREDRAW;         //specifying class styles
    mynewclass.Windows_Procedure;                       //passing pointer of windows procedure
    mynewclass.cbClsExtra = 0;                          //no extra bytes for allocating the window class structure
    mynewclass.cbWndExtra = 0;                          //no extra bytes for the windows instance
    mynewclass.handle_to_win_procedure;                 //specifying the handle to the windows procedure
    mynewclass.hIcon = NULL;                            //if this is null, then application will load a default icon
    mynewclass.hCursor = LoadCursor (NULL, IDC_CROSS)   //specifying the image of the mouse cursor
    mynewclass.hbrBackground = GetStockObject (WHITE_BRUSH) //setting the background of client to a white shade
    mynewclass.lpszMenuName = "Main Menu";                  //specifying the name of window menu
    mynewclass.lpszClassName = "Main Class";                //specifying the name of the window class
    mynewclass.hIconSm = NULL;                             
    
    RegisterClassEx (&mynewclass);
}






//creating main windows

mainWIN = CreateWindowEX (
        0,                          //No extended styles
        "Main Class",               //The name of the window class
        "My Awesome Window",        //the name of the window itself
        WS_OVERLAPPEDWINDOW |       //Style of the window
        WS_HSCROLL | WS_VSCROLL,
        CW_USEDEFAULT,              //default horizontal position
        CW_USEDEFAULT,              //default vertical position
        CW_USEDEFAULT,              //default width
        CW_USEDEFAULT,              //default height
        (HWND) NULL,                //no parent of owner window
        (HMENU) NULL,               //use window menu
        hinstance,                  //instance handle
        null);                      //no window creation data



if (!mainWIN)                       //checking to see if theres any problems with handle to main window
    return false;


 ShowWindow (mainWIN, SW_SHOWMAXIMIZED);  //displays the window
 UpdateWindow (mainWIN);                  //updates window and sends a WS_PAINT message to paint the application









long APIENTRY Windows_Procedure (HWND handle1, UINT message, WPARAM w, LPARAM l)  
{
    RECT coordinates_of_client;                


    switch (message)                        //message will contain an integer value
    {
        case WM_CREATE:                    

            CreateWindowEX                  //creating child window
            (
             0,                             //no extended styles
             "Main Class",                 //name of child window class
             (LPCTSTR) NULL,                //child window will not have a name
             WS_CHILD | WS_BORDER,          //specifying the style of the window
             0,0,0,0,                       //no scrolls or height or width on child window
             handle1,                        //specifying parent window for this child window
             (HMENU) (int) (FirstChild)     //menu for child window
             NULL                           //no windows creation data
            );
            return 0;

        case WM_SIZE:                                         
            GetClientRect (handle1, &coordinates_of_client); 
            EnumChildWindows (handle1, EnumChildProc, (LPARAM)& coordinates_of_client);
            return 0;
    }

    ShowWindow (handle1, SW_SHOW);
    return DefWindowProc (handle1, message, w,l)  
}

[Homberto]

Don't you need a WinMain?
and mynewclass.Windows_Procedure; doesn't exist, nor does it set your Windows_Procedure function as the window procedure of your class.
https://msdn.microsoft.com/en-us/library/windows/desktop/ms633577%28v=vs.85%29.aspx
use:
mynewclass.lpfnWndProc=Windows_Procedure;
I think you should take a look at this tutorial:
http://www.winprog.org/tutorial/start.html
And judging by your save as .exe comment:
http://www.cplusplus.com/doc/tutorial/introduction/

[freddie1]

Yep, some major conceptual problems, but hey! Keep trying!!!

As Homberto said, that Forgers Tutorial is pretty good. Its not that hard to get a Windows Api GUI program up and running. Here's as simple and small of a compilable example as I can come up with. Makes a main program window wit title bar, etc, and compiles to only 7K with my GCC 4.4 series compiler...

//Main.cpp
#ifndef UNICODE
#define UNICODE
#endif
#include <windows.h>

LRESULT CALLBACK fnWndProc(HWND hwnd, unsigned int msg, WPARAM wParam, LPARAM lParam)
{
 if(msg==WM_DESTROY)
 {
    PostQuitMessage(0);
    return 0;
 }

 return (DefWindowProc(hwnd, msg, wParam, lParam));
}


int WINAPI WinMain(HINSTANCE hIns, HINSTANCE hPrevIns, LPSTR lpszArgument, int iShow)
{
 wchar_t szClassName[]=L"Form1";
 WNDCLASSEX wc;
 MSG messages;
 HWND hWnd;

 memset(&wc,0,sizeof(WNDCLASSEX));
 wc.lpszClassName = szClassName;                wc.lpfnWndProc=fnWndProc;
 wc.cbSize        = sizeof (WNDCLASSEX);        wc.hInstance=hIns;
 wc.hbrBackground = (HBRUSH)COLOR_BTNSHADOW;
 RegisterClassEx(&wc);
 hWnd=CreateWindowEx(0,szClassName,szClassName,WS_OVERLAPPEDWINDOW,75,75,320,305,HWND_DESKTOP,0,hIns,0);
 ShowWindow(hWnd,iShow);
 while(GetMessage(&messages,NULL,0,0))
 {
    TranslateMessage(&messages);
    DispatchMessage(&messages);
 }

 return messages.wParam;
}

Saving it as an exe file won't buy you anything more than an error message when you click on it though. A C++ compiler is needed to read in the textural source and spit out binary op codes in the form of an executable file which Windows can recognize and execute.