WIN32程序设计的问题,大家近来看看
我刚学WIN32程序设计不久,以前书上的程序例子都是一个窗口,我今天突发奇想写了个两

个窗口的程序,没想到这个程序把我弄糊涂了.

我先声名了两个窗口过程函数,又声名了2个句柄和窗口类,在2个窗口类分别定义了不同

的窗口过程函数.编译,连接成功,在第一个窗口里按鼠标时弹出MSGBOX显示The first

window,关闭第一个窗口创建第二个窗口后,按鼠标也弹出MSGBOX显示The first window,

而且在WndProc2中处理的F12也不管用,这是怎么回事?

代码如下:
/*------------------------
HELLOWIN.C -- Displays "DOUBLE WINDOWS " in client area
(c) Charles Petzold, 1998
------------------------*/

#include <windows.h>

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;
LRESULT CALLBACK WndProc2 (HWND, UINT, WPARAM, LPARAM) ;
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = TEXT ( "HelloWin ") ;
HWND hwnd ,hwnd2;
MSG msg ;
WNDCLASS wndclass , wndclass2 ;

wndclass.style = CS_HREDRAW | CS_VREDRAW ;
wndclass.lpfnWndProc = WndProc ;
wndclass.cbClsExtra = 0 ;
wndclass.cbWndExtra = 0 ;
wndclass.hInstance = hInstance ;
wndclass.hIcon = LoadIcon (hInstance, "CDMENU ") ;
wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ;
wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
wndclass.lpszMenuName = NULL ;
wndclass.lpszClassName = szAppName ;

wndclass2.style = CS_HREDRAW | CS_VREDRAW ;
wndclass2.lpfnWndProc = WndProc2 ;
wndclass2.cbClsExtra = 0 ;
wndclass2.cbWndExtra = 0 ;
wndclass2.hInstance = hInstance ;

wndclass2.hIcon = LoadIcon (hInstance, "CDMENU ") ;
wndclass2.hCursor = LoadCursor (NULL, IDC_ARROW) ;
wndclass2.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
wndclass2.lpszMenuName = NULL ;
wndclass2.lpszClassName = szAppName ;
if (!RegisterClass (&wndclass))
{
MessageBox (NULL, TEXT ( "This program requires Windows NT! "),
szAppName, MB_ICONERROR) ;
return 0 ;
}
RegisterClass (&wndclass2);

hwnd = CreateWindow (szAppName, // window class name
TEXT ( "The Hello Program "), // window caption
WS_OVERLAPPEDWINDOW, // window style
CW_USEDEFAULT, // initial x position
CW_USEDEFAULT, // initial y position
CW_USEDEFAULT, // initial x size
CW_USEDEFAULT, // initial y size
NULL, // parent window handle

NULL, // window menu handle
hInstance, // program instance handle
NULL) ; // creation parameters

ShowWindow (hwnd, iCmdShow) ;
UpdateWindow (hwnd) ;

while (GetMessage (&msg, NULL, 0, 0))
{
TranslateMessage (&msg) ;
DispatchMessage (&msg) ;
}

hwnd2 = CreateWindow (szAppName, // window class name
TEXT ( "The Hello Program2 "), // window caption
WS_OVERLAPPEDWINDOW, // window style
CW_USEDEFAULT, // initial x position
CW_USEDEFAULT, // initial y position
CW_USEDEFAULT, // initial x size

CW_USEDEFAULT, // initial y size
NULL, // parent window handle
NULL, // window menu handle
hInstance, // program instance handle
NULL) ; // creation parameters

ShowWindow (hwnd2, iCmdShow) ;
UpdateWindow (hwnd2) ;

while (GetMessage (&msg, NULL, 0, 0))
{
TranslateMessage (&msg) ;
DispatchMessage (&msg) ;
}

return msg.wParam ;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{

PAINTSTRUCT ps ;


switch (message)
{

case WM_LBUTTONDOWN:
MessageBox (NULL, TEXT ( "The first window. "),
TEXT( "The first window. "), MB_ICONERROR) ;
return 0 ;
case WM_PAINT:

BeginPaint (hwnd, &ps);

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

LRESULT CALLBACK WndProc2 (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{

PAINTSTRUCT ps ;


switch (message)
{

case WM_KEYUP:
switch(wParam)
{
case VK_F12:
ShowWindow (hwnd, SW_SHOWMAXIMIZED) ;}
return 0;
case WM_LBUTTONDOWN:
MessageBox (NULL, TEXT ( "The second window. "),
TEXT ( "The second "), MB_ICONERROR) ;
return 0 ;
case WM_PAINT:

BeginPaint (hwnd, &ps);

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

[解决办法]
2次创建用的是个同个classname
[解决办法]
两个类名相同,第二个窗口在注册时一定会出错
[解决办法]
HWND CreateWindow(
LPCTSTR lpClassName,
LPCTSTR lpWindowName,
DWORD dwStyle,
int x,
int y,
int nWidth,
int nHeight,
HWND hWndParent,
HMENU hMenu,
HINSTANCE hInstance,
LPVOID lpParam
);
Parameters

lpClassName
[in] Pointer to a null-terminated string or a class atom created by a previous call to the RegisterClass or RegisterClassEx function. The atom must be in the low-order word of lpClassName; the high-order word must be zero. If lpClassName is a string, it specifies the window class name. The class name can be any name registered with RegisterClass or RegisterClassEx, provided that the module that registers the class is also the module that creates the window. The class name can also be any of the predefined system class names. For a list of system class names, see the Remarks section.