Thread: how subclassing controls?

i'm trying build a class for show a STATIC control and use my own windor procedure for it. i was searching in these forum and i found that i can use the procedure inside of class, but must be static.
the procedure seems be activated (i have used a message box), but the msg const's values aren't correct...
see the class:

Code:

#include <windows.h>
#include <iostream>
#include <string>
#include <process.h>

using namespace std;



class label
{
private:

HWND hwnd;

static LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch(msg)
    {
        case WM_CREATE:
            ShowWindow(hwnd,SW_SHOW);
            SetWindowText(hwnd,"hello");

        break;
        case WM_CLOSE:
            DestroyWindow(hwnd);
        break;
        case WM_DESTROY:
            PostQuitMessage(0);
        break;
        default:
            return DefWindowProc(hwnd, msg, wParam, lParam);
    }
    return 0;
}



public:

    label(HWND value)
    {

        hwnd = CreateWindowEx(
            WS_EX_LEFT| WS_EX_LTRREADING | WS_EX_RIGHTSCROLLBAR,
            "STATIC",
            "",
            SS_LEFT|WS_CHILD|WS_VISIBLE,
            0, 0, 100, 100,
            value,
            NULL,
            GetModuleHandle(NULL),
            NULL);

            ShowWindow(hwnd,SW_SHOW);
            UpdateWindow(hwnd);
            SetWindowLong(hwnd, GWL_WNDPROC, (LONG)WndProc);//set your custom procedure :)
    }

    COORD GetSize()
    {
        RECT LabelSize;
        GetWindowRect(hwnd,&LabelSize);
        COORD crdSize={LabelSize.right-LabelSize.left,LabelSize.bottom-LabelSize.top};
        return crdSize;
    }

    void SetText(string text)
    {
        char* chrText=(char*)text.c_str();
        SetWindowText(hwnd, chrText);
    }


};

i see 2 problems with these code(and not error messages):
1 - the control isn't showed. but if i take of the:

Code:

SetWindowLong(hwnd, GWL_WNDPROC, (LONG)WndProc);

inside of constructor, the STATIC is showed.

2 - the window procedure seems be activated, but, like i said, the msg values aren't correct

i have search in these forum without sucess
plase someone tell me what i'm doing wrong

Originally Posted by Codeplug

Haven't looked your code, but here is a thread on the subject of making a OO wrapper for the Win32 API.

Member functions as child window procedures

gg

before i build these thread i have seen that thread, but i didn't find my answer...
seems that i can't do subclassing but window procedure super classing, for get the WM_CREATE and the others too

after more search in these forum i did more work:

Code:

#include <windows.h>
#include <iostream>
#include <string>
#include <process.h>

using namespace std;






class label
{
private:
    HWND hwnd;
    WNDCLASS wc;
    WNDPROC m_pfnPrevWndProc;


static LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    WNDPROC oldproc =(WNDPROC)GetWindowLongPtr(GetParent(hwnd),GWLP_USERDATA);
    UINT i=(UINT)GetWindowLongPtr(GetParent(hwnd),GWLP_USERDATA);
    switch(msg)
    {
        case WM_NCCREATE:
        {
            CREATESTRUCT *createstruct = (CREATESTRUCT*)lParam;

            SetWindowLong(hwnd, GWL_USERDATA, (long)createstruct->lpCreateParams);
        }
        break;
        case WM_CREATE:
        {
            SetWindowText(hwnd,"hello world");

            break;
        }
        case WM_MOUSEMOVE:
        {
            SetWindowText(hwnd,"mouse move");
            break;
        }
        case WM_CLOSE:
            DestroyWindow(hwnd);
        break;
        case WM_DESTROY:
            PostQuitMessage(0);
        break;
        default:
            return (CallWindowProc(oldproc, hwnd, msg, wParam, lParam));
    }
    return DefWindowProc(hwnd, msg, wParam, lParam);
}

public:

    label(HWND value)
    {


    ZeroMemory(&wc, sizeof(WNDCLASS));
    GetClassInfo((HINSTANCE)GetModuleHandle(NULL), "STATIC", &wc);

    wc.hInstance = (HINSTANCE)GetModuleHandle(NULL);
    wc.lpszClassName = "CSTATIC";

    // store the old WNDPROC of the EDIT window class
    m_pfnPrevWndProc = wc.lpfnWndProc;

    // replace it with local WNDPROC
    wc.lpfnWndProc = WndProc;

    // register the new window class, "ShEdit"
    if (!RegisterClass(&wc)) MessageBox(NULL,"error","error",MB_OK);
        hwnd = CreateWindowEx(
            WS_EX_LEFT| WS_EX_LTRREADING | WS_EX_RIGHTSCROLLBAR,
            "CSTATIC",
            "hello",
            SS_LEFT|WS_CHILD|WS_VISIBLE,
            0, 0, 100, 100,
            value,
            NULL,
            GetModuleHandle(NULL),
            NULL);
            if(hwnd==NULL) MessageBox(NULL,"error","error",MB_OK);
            SetWindowLongPtr (GetParent(hwnd),GWLP_USERDATA,(LONG_PTR)m_pfnPrevWndProc);
            ShowWindow(hwnd,SW_SHOW);
            UpdateWindow(hwnd);

    }

    COORD GetSize()
    {
        RECT LabelSize;
        GetWindowRect(hwnd,&LabelSize);
        COORD crdSize={LabelSize.right-LabelSize.left,LabelSize.bottom-LabelSize.top};
        return crdSize;
    }

    void SetText(string text)
    {
        char* chrText=(char*)text.c_str();
        SetWindowText(hwnd, chrText);
    }


};

the control is showed, but the window procedure isn't right... because i don't have access to WM_CREATE and others

Originally Posted by Codeplug

There are basically 2 methods for making an OO wrapper for Win32: the MFC way and the ATL way. The thunk'n method that I showed in the linked thread is the ATL way. The MFC way uses hooks and re-classing on CE. Here is another thread on that: Puting win32 callbacks into a class

The links in that thread no longer work, but they exist in the internet archive:
https://web.archive.org/web/20090131...ce_prefix.html
https://web.archive.org/web/20060103...icles/wndproc/

gg

sorry.. i'm using the Code Blocks IDE.