【Demo 0027】获取窗体类信息（2）

在上一节中我们有测试过使用GetClassInfoEx读取不到窗体类信息，我们这一节将学习通过GetClassLongPtr获取非窗体所在的进程类信息

(一) 函数声明

      ULONG_PTR GetClassLongPtr(HWND hWnd, int nIndex );

      获取指定窗体（可进程也可进程外）特定类信息项值（数据源：窗体类分配的WNDCLASSEX参数值），可支持32、64位的OS

      DWORD GetClassLong(HWND hWnd, int nIndex);

      功能同GetClassLongPtr， 仅支持32位的OS

      nIndex 值参考:

      GCW_ATOM

Retrieves an ATOM value that uniquely identifies the window class. This is the same atom that the RegisterClassEx function returns.

GCL_CBCLSEXTRA

Retrieves the size, in bytes, of the extra memory associated with the class.

GCL_CBWNDEXTRA

Retrieves the size, in bytes, of the extra window memory associated with each window in the class.

For information on how to access this memory, see GetWindowLongPtr.

GCLP_HBRBACKGROUND

Retrieves a handle to the background brush associated with the class.

GCLP_HCURSOR

Retrieves a handle to the cursor associated with the class.

GCLP_HICON

Retrieves a handle to the icon associated with the class.

GCLP_HICONSM

Retrieves a handle to the small icon associated with the class.

GCLP_HMODULE

Retrieves a handle to the module that registered the class.

GCLP_MENUNAME

Retrieves the pointer to the menu name string. The string identifies the menu resource associated with the class.

GCL_STYLE

Retrieves the window-class style bits.

GCLP_WNDPROC

Retrieves the address of the window procedure, or a handle representing the address of the window procedure.

You must use the CallWindowProc function to call the window procedure.

 

      Code:  以下代码演示

      1.  获取NotePad窗体句柄

      2.  获取NotePad 类信息通过（GetClassLongPtr)       

     

HWND hWndNotePad = FindWindowEx(NULL, NULL, _T("Notepad"), NULL);
if (NULL != hWndNotePad && IsWindow(hWndNotePad))
{
    int        nIndexList[]    = { GCW_ATOM, GCL_CBCLSEXTRA, GCL_CBWNDEXTRA, GCLP_HBRBACKGROUND, GCLP_HCURSOR,
                                GCLP_HICON, GCLP_HICONSM, GCLP_HMODULE, GCLP_MENUNAME, GCL_STYLE, GCLP_WNDPROC };
    int*    nValueList        = new int[sizeof(nIndexList) / sizeof(*nIndexList)];
    const TCHAR* szInfo[]    = { _T("Atom:\t\t    0x%06X\n"),
                                _T("class Extra:\t    0x%06X\n"),
                                _T("Wnd Extra:        0x%06X\n"),   
                                _T("hBackground:        0x%06X\n"),
                                _T("hCursor:\t        0x%06X\n"),
                                _T("hIcon:            0x%06X\n"),
                                _T("hIconSM:        0x%06X\n"),
                                _T("hModule:        0x%06X\n"),
                                _T("MenuName:        0x%06X\n"),
                                _T("Style:            0x%06X\n"),
                                _T("WndProc:        0x%06X\n")};
    assert((sizeof(nIndexList) / sizeof(*nIndexList)) == (sizeof(szInfo) / sizeof(*szInfo)));
    
    TCHAR szClassInfo[1024] = {0};
    TCHAR szTemp[256];
    for (int ii = 0; ii < sizeof(nIndexList) / sizeof(*nIndexList); ii++)
    {
        nValueList[ii] = GetClassLongPtr(hWndNotePad, nIndexList[ii]);

        TCHAR szTemp[256];
        _stprintf_s(szTemp, szInfo[ii], nValueList[ii]);
        _tcscat(szClassInfo, szTemp);
    }
    SetWindowText(GetDlgItem(hWnd, ID_LABINFO), szClassInfo);
    OutputDebugString(szClassInfo);
    delete[] nValueList;
}

       我们读取后的值与SPY++ 中类信息对比

     

      疑问： 1.  MenuName 不一致;

                2.  根据hCursor句柄值如何得到对应的资源ID == IDC_IBEAM

                3.  根据hBackground句柄值如何得到对应的资源ID == COLOR_WINDOW

    

(二) 特别说明

      此函数返回的数据没有WNDCLASSEX项多

      对于以上疑问需努力学习！

演示代码