[C++] GUI: Button Creation & How to use [Source+TuT]

Fabr3gas · 17 Feb 2011 23:51

We will be creating a button.
First of all you must create your button ID and HWND globaly like so

#define BUTTON1 100 // I used 100 as an example you can use any number
HWND   BTN1;

Now comes the Button Creation. You must place it somewhere where the Window Loads.

You could put it under WM_CREATE, But I chose not to because why would you wait for the loop to start to create the button? I guess its just a minor performance thing.

Here is how you create it. (View source at bottom of post for placement)

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BTN1 = CreateWindowExW(NULL,
            L"BUTTON",
            L"Click me!",
            WS_TABSTOP|WS_VISIBLE|WS_CHILD|BS_DEFPUSHBUTTON,
            100,/*x*/
            100,/*y*/
            100,/*width*/
            24,/*height*/
            hWnd,
            (HMENU)BUTTON1,//Button ID
            GetModuleHandle(NULL),
            NULL);

After inserting that, you would obvisously want to do something when the user clicks the button right? Well, we must add that in the MSG Loop.

Here is our MSG loop found the the other thread.

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            case WM_DESTROY: // When user exists app
                {
                    PostQuitMessage(0);
                    return 0;
                }
                break;
                
            }
    }

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

Where is says

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switch(LOWORD(wParam))
                    {

                    default:{break;}
                    }
                break;

We must add a `case` between it so that it does something when the user clicks the button. so What we want to do is add our Button ID we made earlier.

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switch(LOWORD(wParam))
                    {
                     case BUTTON1: {
                                              //Do Something here.
                                              MessageBoxA(NULL,"You Clicked the Button!", "Hey LC!",MB_ICONINFORMATION|MB_OK);
                                           }

                    default:{break;}
                    }
                break;

This is the code you should have.

FULL CODE:

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#include <windows>
#include <iostream>

//Windows Theme/////////
#pragma comment(linker,"/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")
///////////////////////
LRESULT CALLBACK WinProc(HWND hWnd,UINT message,WPARAM wParam,LPARAM lParam);

LPCWSTR Form_Title = L"BlueMelon"; // Form Title

#define BUTTON1 100
HWND    BTN1;

using namespace std;

int WINAPI WinMain(HINSTANCE hInst,HINSTANCE hPrevInst,LPSTR lpCmdLine,int nShowCmd)
{
    WNDCLASSEXW wClass;
    ZeroMemory(&wClass,sizeof(WNDCLASSEXW));

    wClass.cbClsExtra = NULL;
    wClass.cbSize = sizeof(WNDCLASSEXW);
    wClass.cbWndExtra = NULL;
    wClass.hbrBackground =(HBRUSH)COLOR_WINDOW;
    wClass.hCursor = LoadCursor(NULL,IDC_ARROW);
    wClass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wClass.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
    wClass.hInstance = hInst;
    wClass.lpfnWndProc = (WNDPROC)WinProc;
    wClass.lpszClassName = L"Window Class";
    wClass.lpszMenuName = NULL;
    wClass.style = CS_HREDRAW|CS_VREDRAW;

    if(!RegisterClassEx(&wClass))
    {
        int nResult=GetLastError();
        MessageBoxA(NULL,"Window class creation failed","Window Class Failed",MB_ICONERROR);
    }

    HWND hWnd = CreateWindowExW(NULL, // Creating your window
                L"Window Class",
                Form_Title, // Form Title (As declared earlier)
                WS_VISIBLE|WS_OVERLAPPEDWINDOW,
                CW_USEDEFAULT,/*x*/ //Default
                CW_USEDEFAULT,/*y*/    //Default
                300,/*width*/
                300,/*height*/
                NULL,
                NULL,
                hInst,
                NULL);

    if(!hWnd)
    {
        MessageBoxA(NULL,"Window creation failed","Window Creation Failed",MB_ICONERROR);
    }


    BTN1 = CreateWindowExW(NULL,
            L"BUTTON",
            L"Click me!",
            WS_TABSTOP|WS_VISIBLE|WS_CHILD|BS_DEFPUSHBUTTON,
            100,/*x*/
            100,/*y*/
            100,/*width*/
            24,/*height*/
            hWnd,
            (HMENU)BUTTON1,//Button ID
            GetModuleHandle(NULL),
            NULL);


    ShowWindow(hWnd,nShowCmd);

    MSG msg;
    ZeroMemory(&msg,sizeof(MSG));

    


    while(GetMessage(&msg,NULL,0,0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg); // Send into Loop
    }

    return 0;
}



LRESULT CALLBACK WinProc(HWND hWnd,UINT msg,WPARAM wParam,LPARAM lParam)
{
    switch(msg) // msg loop
    {
        case WM_COMMAND:
            {
                switch(LOWORD(wParam)) // Used for controls to be added later
                    {
                         case BUTTON1: {
                                              //Do Something here. Example:
                                              MessageBoxA(BTN1,"You Clicked the Button!", "Hey LC!",MB_ICONINFORMATION|MB_OK);
                                       }
                    default:{break;}
                    }
                break;
        
                

            case WM_DESTROY: // When user exists app
                {
                    PostQuitMessage(0);
                    return 0;
                }
                break;
                
            }
    }

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

You can also do more stuff to your button:
Enable/Disable

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EnableWindow( GetDlgItem(hWnd,BUTTON1), false );//Disable
EnableWindow( GetDlgItem(hWnd,BUTTON1), true ); // Enable

Set Text

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SetWindowTextA(BTN1,"YourText");

Those also work for most controls.

Credits to BlueMelon.