writing text over a deleted button

This is a discussion on writing text over a deleted button within the Windows Programming forums, part of the Platform Specific Boards category; In this example programme, i have a function that is called when a button is pressed, and the button get's ...

  1. #1
    yes, I'm registered!!! algi's Avatar
    Join Date
    Nov 2004
    Location
    Ipswich
    Posts
    161

    writing text over a deleted button

    In this example programme, i have a function that is called when a button is pressed, and the button get's deleted. The problem is in the function that the button calls, some of the text can't be seen, because the location where the button used to be has left a white space. I think it might be because i deleted the button after i called the function but i can't put it before or something really weird happens and the text isn't printed in the window.

    Does anybody know a solution to this.

    Code:
    #include <windows.h>
    
    /*  Declare Windows procedure  */
    LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);
    
    /*  Make the class name into a global variable  */
    char szClassName[ ] = "WindowsApp";
    HINSTANCE hInstGlobal;
    
    int WINAPI WinMain (HINSTANCE hThisInstance,
                        HINSTANCE hPrevInstance,
                        LPSTR lpszArgument,
                        int nFunsterStil)
    
    {
        HWND hwnd;               /* This is the handle for our window */
        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 Windows's default color as the background of the window */
        wincl.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH);
    
        /* Register the window class, and if it fails 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 */
               );
    
        /* Make the 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;
    }
    
    
    HWND hButton;
    
    void buttonpressed(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
    {
         HDC hdc;
         hdc = GetDC (GetParent((HWND) lParam));
         HFONT font;
         PAINTSTRUCT ps;
         font = CreateFont(30, 0, 0, 0,
                               FW_NORMAL, FALSE, FALSE, FALSE,
                               ANSI_CHARSET, OUT_DEFAULT_PRECIS,
    		         CLIP_DEFAULT_PRECIS, DEFAULT_QUALITY,
    		         DEFAULT_PITCH | FF_ROMAN,
    			"Times New Roman");
    
            SelectObject(hdc, font);
            TextOut(hdc, 10, 10, "When i delete a button the text cannot be seen!", 47);
            DeleteObject(font);
    
    	EndPaint(hwnd, &ps);
    	
    }
    
    /*  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_CREATE:
                 hButton = CreateWindow ("BUTTON", "Press Me",
                                         WS_CHILD | WS_VISIBLE |
                                         BS_PUSHBUTTON,
                                         10, 10, 140, 20,
                                         hwnd, (HMENU) 1,
                                         hInstGlobal, NULL);
                 return 0;
            case WM_COMMAND:
                 if (HIWORD(wParam) == BN_CLICKED)
                 {
                      if (LOWORD(wParam) == 1)
                      {
                           buttonpressed(hwnd, message, wParam, lParam);
                           DestroyWindow(hButton);
                           return 0;
                           }
                           return 0;
                           }
                      return 0;
                 
            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;
    }
    It is supposed to say
    "When i deelete a button the text cannot be seen"
    I started out with nothing and I still have most of it left.

  2. #2
    erstwhile
    Join Date
    Jan 2002
    Posts
    2,227
    BeginPaint....EndPaint should only be called in the context of a WM_PAINT handler where you should move your drawing code anyway. To effect the update in drawing in response to the button click then call InvalidateRect in your BN_CLICKED notification message handler.
    CProgramming FAQ
    Caution: this person may be a carrier of the misinformation virus.

  3. #3
    train spotter
    Join Date
    Aug 2001
    Location
    near a computer
    Posts
    3,859
    You can create two controls one on top of the other. Then there is no need to draw on the window.....

    Then just hide the button and show the text (static control)

    Use ShowWindow() SW_HIDE SW_SHOW. When creating the controls set the WS_VISIBLE for the one you want to see and remove it (or call ShowWindow) one the one you want to hide.
    "Man alone suffers so excruciatingly in the world that he was compelled to invent laughter."
    Friedrich Nietzsche

    "I spent a lot of my money on booze, birds and fast cars......the rest I squandered."
    George Best

    "If you are going through hell....keep going."
    Winston Churchill

  4. #4
    yes, I'm registered!!! algi's Avatar
    Join Date
    Nov 2004
    Location
    Ipswich
    Posts
    161
    hey thanks, by hiding it before i call the function i can see all the text
    I started out with nothing and I still have most of it left.

  5. #5
    yes, I'm registered!!! algi's Avatar
    Join Date
    Nov 2004
    Location
    Ipswich
    Posts
    161
    Disabling the button worked but in the function that i call, if i create a button in that function the problem comes back.

    This is what i now have, but with the same problem.
    Code:
    #include <windows.h>
    
    /*  Declare Windows procedure  */
    LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);
    
    /*  Make the class name into a global variable  */
    char szClassName[ ] = "WindowsApp";
    HINSTANCE hInstGlobal;
    
    int WINAPI WinMain (HINSTANCE hThisInstance,
                        HINSTANCE hPrevInstance,
                        LPSTR lpszArgument,
                        int nFunsterStil)
    
    {
        HWND hwnd;               /* This is the handle for our window */
        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 Windows's default color as the background of the window */
        wincl.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH);
    
        /* Register the window class, and if it fails 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 */
               );
    
        /* Make the 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;
    }
    
    
    HWND hButton, hName;
    
    
    void buttonpressed(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
    {
         
         HDC hdc;
         
         hdc = GetDC (GetParent((HWND) lParam));
         HFONT font;
         PAINTSTRUCT ps;
         font = CreateFont(30, 0, 0, 0,
                               FW_NORMAL, FALSE, FALSE, FALSE,
                               ANSI_CHARSET, OUT_DEFAULT_PRECIS,
    		         CLIP_DEFAULT_PRECIS, DEFAULT_QUALITY,
    		         DEFAULT_PITCH | FF_ROMAN,
    			"Times New Roman");
    
            SelectObject(hdc, font);
            TextOut(hdc, 10, 10, "When i delete a button the text cannot be seen!", 47);
            DeleteObject(font);
    
    	EndPaint(hwnd, &ps);
    	
    	
    	
    }
    
    void buttonpressedl(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
    {
         buttonpressed(hwnd, message, wParam, lParam);
    }
    
    /*  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_CREATE:
                 hButton = CreateWindow ("BUTTON", "Press Me",
                                         WS_CHILD | WS_VISIBLE |
                                         BS_PUSHBUTTON,
                                         10, 10, 140, 20,
                                         hwnd, (HMENU) 1,
                                         hInstGlobal, NULL);
                 
                 return 0;
            case WM_COMMAND:
                 if (HIWORD(wParam) == BN_CLICKED)
                 {
                      if (LOWORD(wParam) == 1)
                      {
                           ShowWindow(hButton, SW_HIDE);
                          
                           
                           
                           buttonpressedl(hwnd, message, wParam, lParam);
                            DestroyWindow(hButton);
                           return 0;
                           }
                           return 0;
                           }
                      return 0;
                 
            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;
    }
    I started out with nothing and I still have most of it left.

Popular pages Recent additions subscribe to a feed

Similar Threads

  1. DirectX | Drawing text
    By gavra in forum Game Programming
    Replies: 4
    Last Post: 06-08-2009, 12:23 AM
  2. Folding@Home Cboard team?
    By jverkoey in forum A Brief History of Cprogramming.com
    Replies: 398
    Last Post: 10-11-2005, 08:44 AM
  3. Radio button linked to text box
    By J_Bravo in forum Windows Programming
    Replies: 9
    Last Post: 05-07-2002, 10:15 PM
  4. text on owner-drawn button?
    By SyntaxBubble in forum Windows Programming
    Replies: 5
    Last Post: 02-17-2002, 12:08 PM
  5. Writing to a column in a text file
    By olland in forum C Programming
    Replies: 2
    Last Post: 01-21-2002, 05:40 AM

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21