windows窗口和子窗口消息传递的问题
下面的代码一部分时Dev-C++自己生成的，一部分是从教程copy的，我想问的是在WM_COMMAND消息里怎样区分一个消息是从哪个按钮传递的，谢谢了
#include <windows.h>struct{ int iStyle ; TCHAR * szText ; }button[] = { BS_PUSHBUTTON, TEXT ("PUSHBUTTON"), BS_DEFPUSHBUTTON, TEXT ("DEFPUSHBUTTON"), BS_CHECKBOX, TEXT ("CHECKBOX"), BS_AUTOCHECKBOX, TEXT ("AUTOCHECKBOX"), BS_RADIOBUTTON, TEXT ("RADIOBUTTON"), BS_3STATE, TEXT ("3STATE"), BS_AUTO3STATE, TEXT ("AUTO3STATE"), BS_GROUPBOX, TEXT ("GROUPBOX"), BS_AUTORADIOBUTTON, TEXT ("AUTORADIO"), BS_OWNERDRAW, TEXT ("OWNERDRAW") } ; #define NUM (sizeof button / sizeof button[0])/* Declare Windows procedure */LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);/* Make the class name into a global variable */char szClassName[ ] = "My firest window form application";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 */ HBRUSH br = CreateSolidBrush(RGB(255,255,255)); wincl.hbrBackground = br; // wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND; /* 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 */ "My firest windows form application", /* Title Text */ WS_OVERLAPPEDWINDOW, /* default window */ CW_USEDEFAULT, /* Windows decides the position */ CW_USEDEFAULT, /* where the window ends up on the screen */ 800, /* The programs width */ 600, /* 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;}/* This function is called by the Windows function DispatchMessage() */LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam){ static int iCount; static HWND hwndButton[NUM] ; static RECT rect ; static TCHAR szTop[] = TEXT ("message wParam lParam"), szUnd[] = TEXT ("_______ ______ ______"), szFormat[] = TEXT ("%-16s%04X-%04X %04X-%04X"), szBuffer[50] ; static int cxChar, cyChar ; int i; char *p; p = "abckefsdf"; HDC hdc; PAINTSTRUCT ps; switch (message) /* handle the messages */ { case WM_CREATE : cxChar = LOWORD (GetDialogBaseUnits ()) ; cyChar = HIWORD (GetDialogBaseUnits ()) ; for (i = 0 ; i < NUM ; i++) hwndButton[i] =CreateWindow ( TEXT("button"),button[i].szText, WS_CHILD | WS_VISIBLE | button[i].iStyle, cxChar, cyChar * (1 + 2 * i), 20 * cxChar, 7 * cyChar / 4,hwnd, (HMENU) i, ((LPCREATESTRUCT) lParam)->hInstance, NULL) ; return 0 ; case WM_DESTROY: PostQuitMessage (0); /* send a WM_QUIT to the message queue */ break; case WM_PAINT: InvalidateRect (hwnd, &rect, TRUE) ; hdc = BeginPaint (hwnd, &ps) ; TextOut(hdc,50,100,"刘备",0); TextOut(hdc,50,100,TEXT("xxy"),0); SelectObject (hdc, GetStockObject (SYSTEM_FIXED_FONT)) ; SetBkMode (hdc, TRANSPARENT) ; TextOut (hdc, 24 * cxChar, cyChar, szTop, lstrlen (szTop)) ; TextOut (hdc, 24 * cxChar, cyChar, szUnd, lstrlen (szUnd)) ; EndPaint (hwnd, &ps) ; return 0 ; case WM_LBUTTONDOWN: iCount = 0; InvalidateRect(hwnd,NULL,TRUE); TextOut(hdc,50,100,"刘备",0); break; case WM_RBUTTONDOWN: break; case WM_SIZE: rect.left = 24 * cxChar ; rect.top = 2 * cyChar ; rect.right = LOWORD (lParam) ; rect.bottom = HIWORD (lParam) ; return 0 ; case WM_COMMAND : ScrollWindow (hwnd, 0, -cyChar, &rect, &rect) ; hdc = GetDC (hwnd) ; SelectObject (hdc, GetStockObject (SYSTEM_FIXED_FONT)) ; TextOut(hdc, 24 * cxChar, cyChar * (rect.bottom / cyChar - 1),szBuffer,wsprintf (szBuffer, szFormat, message == WM_DRAWITEM ? TEXT ("WM_DRAWITEM") :TEXT ("WM_COMMAND"), HIWORD (wParam), LOWORD (wParam), HIWORD (lParam), LOWORD (lParam))) ; ReleaseDC (hwnd, hdc) ; ValidateRect (hwnd, &rect) ; break ; default: /* for messages that we don't deal with */ return DefWindowProc (hwnd, message, wParam, lParam); } return 0;}