Buttons + Edit Control

Im making a calculator and i want to press a button and display the value in the edit control using SetDlgItemInt().Not sure if im using it correctly but my code isn't compiling correctly the code runs ok if i remove the function.Any help much appreciated

Code:

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//Includes the WinAPI
#include <windows.h>

// Variables
HWND hwndMain, hwndEdit, hwndButton; // Main window HWND and the edit window HWND

COLORREF crEditBg, crEditFg;
HBRUSH hbrEditBg;

int number = 5;

// Functions
//Callback function
LRESULT CALLBACK MainWndProc(HWND hwnd,                        // Handle of window which received this message
                                                        UINT msg,                        // The message
                                                        WPARAM wParam,                // Extra Information
                                                        LPARAM lParam);        // Extra Information
 

//The entry point of a windows application
int WINAPI
WinMain(HINSTANCE hInstance,                        /* Handle to the current instance*/
                HINSTANCE hPrevInstance,                /* Handle to the previuos instance*/
                LPSTR lpCmdLine,                                /* Pointer to the command line arguements*/
                int nCmdShow)                                        /* Show state of the window wether the window should be maximised or minimised*/
{
        MSG msg;                                                        // MSG structure to store messages
        WNDCLASSEX wcx;                                                // WINDOW class iunformation

        // Fill in the WNDCLASS Struct
        wcx.cbSize = sizeof(WNDCLASSEX);        // Window size. Must always be sizeof(WNDCLASSEX)
        wcx.style = 0;                                                // Class Styles
        wcx.lpfnWndProc = MainWndProc;                // Pointer to the callback procedure******
        wcx.cbClsExtra = 0;                                        // Extra byte to allocate following the wndclassex structure
        wcx.cbWndExtra = 0;                                        // Extra byte to allocate following an instance of the structure
        wcx.hInstance = hInstance;                        // Instance of the application
        wcx.hIcon = LoadIcon (NULL, IDI_APPLICATION);  //Class Icon
        wcx.hCursor = LoadCursor (NULL, IDC_ARROW);  //Class Cursor
        wcx.hbrBackground = (HBRUSH) (COLOR_WINDOW+1);  //Background brush/Colour
        wcx.lpszMenuName = NULL;                        // Main Resource
        wcx.lpszClassName = "Draw";                        // Name of this class
        wcx.hIconSm = NULL;                                        // Small icon for the window

        // Register class with MS-Windows
        if(!RegisterClassEx(&wcx))
                return 0;
       
        //Create instances of the window now that it has been registered
        hwndMain = CreateWindowEx(WS_EX_CLIENTEDGE,  //Extended window style
                                        "Draw",                                // Window class name
                                        "Calculator",                // Window Title
                                        WS_OVERLAPPEDWINDOW, //Window Style
                                        CW_USEDEFAULT,                // Default X-position of window
                                        CW_USEDEFAULT,                // Default Y-position of window
                                        170,                                // Width of the window
                                        220,                                // Height of the window
                                        NULL,                                // Handle of parent window
                                        NULL,                                // Handle to menu
                                        hInstance,                        // Handle to application instance
                                        NULL);                                // Pointer to window creation data

        // Initialise colors
        crEditFg = RGB(0,0,0);                                // BLACK ON
        crEditBg = RGB(255,255,255);                // WHITE

// Create Edit window
        hwndEdit = CreateWindowEx(WS_EX_CLIENTEDGE,
                                                        "EDIT",
                                                        "0",
                                                        WS_BORDER|WS_VISIBLE|WS_CHILD|ES_NUMBER|ES_RIGHT,
                                                        0,0,160,30,
                                                        hwndMain,
                                                        NULL,
                                                        hInstance,
                                                        NULL);

/////////////Create Buttons Here//////////
        hwndButton = CreateWindowEx(0,"BUTTON","1",WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON,0,110,40,40,hwndMain,NULL,hInstance,NULL);
       
        hwndButton = CreateWindowEx(0,"BUTTON","2",WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON,40,110,40,40,hwndMain,NULL,hInstance,NULL);

        hwndButton = CreateWindowEx(0,"BUTTON","3",WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON,80,110,40,40,hwndMain,NULL,hInstance,NULL);
       
        hwndButton = CreateWindowEx(0,"BUTTON","4",WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON,0,70,40,40,hwndMain,NULL,hInstance,NULL);

        hwndButton = CreateWindowEx(0,"BUTTON","5",WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON,40,70,40,40,hwndMain,NULL,hInstance,NULL);

        hwndButton = CreateWindowEx(0,"BUTTON","6",WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON,80,70,40,40,hwndMain,NULL,hInstance,NULL);

        hwndButton = CreateWindowEx(0,"BUTTON","7",WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON,0,30,40,40,hwndMain,NULL,hInstance,NULL);

        hwndButton = CreateWindowEx(0,"BUTTON","8",WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON,40,30,40,40,hwndMain,NULL,hInstance,NULL);

        hwndButton = CreateWindowEx(0,"BUTTON","9",WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON,80,30,40,40,hwndMain,NULL,hInstance,NULL);

        hwndButton = CreateWindowEx(0,"BUTTON","0",WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON,0,150,40,40,hwndMain,NULL,hInstance,NULL);

        hwndButton = CreateWindowEx(0,"BUTTON","+",WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON,120,30,40,40,hwndMain,NULL,hInstance,NULL);

        hwndButton = CreateWindowEx(0,"BUTTON","-",WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON,120,70,40,40,hwndMain,NULL,hInstance,NULL);

        hwndButton = CreateWindowEx(0,"BUTTON","*",WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON,120,110,40,40,hwndMain,NULL,hInstance,NULL);

        hwndButton = CreateWindowEx(0,"BUTTON","/",WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON,120,150,40,40,hwndMain,NULL,hInstance,NULL);

        hwndButton = CreateWindowEx(0,"BUTTON","=",WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON,40,150,40,40,hwndMain,NULL,hInstance,NULL);

        hwndButton = CreateWindowEx(0,"BUTTON","C",WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON,80,150,40,40,hwndMain,NULL,hInstance,NULL);

        ShowWindow(hwndMain,nCmdShow);

        //^^^^Code above creates the window + edit box + buttons and shows them^^^^

        //Process messages coming to this window
        //this code is polling the system
        while(GetMessage(&msg,NULL,0,0))
        {
                TranslateMessage(&msg);                        // Translates virtual key messages to character mesages
                DispatchMessage(&msg);               
        }
        //Return value to the system
        return msg.wParam;
}

// Callback function for the Main Window class
LRESULT CALLBACK MainWndProc(HWND hwndMain,  // Handle of window which received this message(you may have created more then 1 window)
                                                        UINT msg,                // The message which has been sent
                                                        WPARAM wParam,                         
                LPARAM lParam)  // Extra information
{
        switch(msg)
        {
        case WM_DESTROY:                                        // This is the message sent WM_DESTROY
                //User closed the window
                PostQuitMessage(0);                                // The arguement to PostQuitMessage is the return value of the system
                break;
                //Code to show number in Edit Control
        case WM_COMMAND:
                if(LOWORD(wParam) == 1){
                if(HIWORD(wParam) == BN_CLICKED){
                                        SetDlgItemInt(HWND,hwndEdit,number,TRUE);
                }
          }
                break;
        default:
                //Call the default window handler
                return DefWindowProc(hwndMain,msg,wParam,lParam);
        }
        return 0;
}

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I got your code to work. First off you need to make sure, where you are creating the button windows that the hwnd and Main don't get separated. That might have been just a typo. Second The SetDlgItemInt function. You have it like this:

Code:

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SetDlgItemInt(HWND,hwndEdit,number,TRUE);

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It should be like this, I looked up the syntax on msdn:

Code:

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SetDlgItemInt(hwndEdit,1,number,TRUE);

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.
I don't know if the 1 is the value you wanted but that parameter needs to be an integer, so I just plugged 1 in. It compiled fine after I changed that. Hope that helps.

The code compiles fine now thanks but it doesn't display the value in the window any suggestions?

You mean the hwndEdit window when you click a button it won't show? I noticed that and was checking it out. It looks like you didn't make a window process for the buttons. So when you click them the messages have nowhere to go so they don't do anything.

I'm a 100% newbie so can you explain to me what that means or how i make a window process for the buttons.very grateful.

Well I see now that i have to give the buttons seperate ID's but still its not working

Yes they need separate ID's. That's the easiest way to go. There is another way to do it but you have to write a whole separate LRESULT CALLBACK function, like the one you write for the window. The one that looks like this:

Code:

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LRESULT CALLBACK WndProc(HINSTANCE hInstance,HINSTANCE hPrevInstance,PSTR szCmdLine, int iCmdShow)
{

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That was the way I was talking about, it takes a little more work but it is more flexible. For your purposes defining an ID should work. I wrote this simple program that has a button in a window that when clicked a message box pops up. I will just post the program's whole code, since its only function is to have that button and when clicked pop up a message box so it shouldn't be confusing at all.

Code:

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#include <windows.h>
#define ID_PUSHBTN 0                /* Defining the button's ID. */

static int x,y;
HWND hwnd2;
LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);

int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,PSTR szCmdLine,int iCmdShow)
{
static TCHAR szAppName[]=TEXT("Button test");
MSG msg;
HWND hwnd;
WNDCLASS wc;
x=GetSystemMetrics(SM_CXSCREEN);
y=GetSystemMetrics(SM_CYSCREEN);

wc.style=CS_HREDRAW|CS_VREDRAW;
wc.lpfnWndProc=WndProc;
wc.cbWndExtra=0;
wc.cbClsExtra=0;
wc.hInstance=hInstance;
wc.hIcon=LoadIcon(NULL,IDI_APPLICATION);
wc.hCursor=LoadCursor(NULL,IDC_ARROW);
wc.hbrBackground=(HBRUSH)(COLOR_WINDOW+1);
wc.lpszMenuName=NULL;
wc.lpszClassName=szAppName;

if(!RegisterClass(&wc))
{
MessageBox(NULL,"This program requires Windows NT!","ERROR",MB_ICONERROR);
return 0;
}
hwnd=CreateWindow(szAppName,szAppName,WS_OVERLAPPEDWINDOW,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,NULL,NULL,hInstance,NULL);
hwnd2=CreateWindowEx(WS_EX_CLIENTEDGE,"BUTTON","Click me!",WS_CHILD|WS_VISIBLE|BS_PUSHBUTTON,x/2,y/2,75,25,hwnd,ID_PUSHBTN,hInstance,NULL);                /* The button's window being created. */

ShowWindow(hwnd,SW_MAXIMIZE);
UpdateWindow(hwnd);

while(GetMessage(&msg,NULL,0,0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return msg.wParam;
}
LRESULT CALLBACK WndProc(HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam)                /* Main window's CALLBACK function. */
{
PAINTSTRUCT ps;
HDC hdc;
switch (message)
{
case WM_COMMAND:                /* This is the part you need to look at */
switch(LOWORD(wParam))                /* This is where the message that the button has been clicked is sent */
{
case ID_PUSHBTN:                        /* Just like the WM cases but it is case BUTTON_ID
MessageBox (NULL, "Button has been clicked!" , "Clicked!", MB_ICONQUESTION);                /* The code to be executed when the button is clicked. */
break;
}
return 0;

case WM_DESTROY:
PostQuitMessage(0);
return 0;
}
return DefWindowProc(hwnd,message,wParam,lParam);
}

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That code should work, it does for Dev-C++.