WM_CREATE讯息中创建控件不显示

2013-04-21

WM_CREATE消息中创建控件不显示今天小弟用想在VC上自动创建的那个WIN32窗口程序上加几个控件，可是在WM_CRE

WM_CREATE消息中创建控件不显示
今天小弟用想在VC上自动创建的那个WIN32窗口程序上加几个控件，可是在WM_CREATE的消息处理过程创建总是显示不出来，在WM_PAINT中创建就可以，还请大神赐教下面是代码

#include "stdafx.h"
#include "resource.h"

#define MAX_LOADSTRING 100

// Global Variables:
HINSTANCE hInst;// current instance
TCHAR szTitle[MAX_LOADSTRING];// The title bar text
TCHAR szWindowClass[MAX_LOADSTRING];
HWND g_Hwnd;
HWND g_Button;
HWND g_TBLogin;
HWND g_TBPass;// The title bar text

// Foward declarations of functions included in this code module:
ATOMMyRegisterClass(HINSTANCE hInstance);
BOOLInitInstance(HINSTANCE, int);
LRESULT CALLBACKWndProc(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACKAbout(HWND, UINT, WPARAM, LPARAM);

int APIENTRY WinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,
                     int       nCmdShow)
{
// TODO: Place code here.
MSG msg;
HACCEL hAccelTable;

// Initialize global strings
LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
LoadString(hInstance, IDC_VIEW, szWindowClass, MAX_LOADSTRING);
MyRegisterClass(hInstance);

// Perform application initialization:
if (!InitInstance (hInstance, nCmdShow))
{
return FALSE;
}

hAccelTable = LoadAccelerators(hInstance, (LPCTSTR)IDC_VIEW);

// Main message loop:
while (GetMessage(&msg, NULL, 0, 0))
{
if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}

return msg.wParam;
}

//
//  FUNCTION: MyRegisterClass()
//
//  PURPOSE: Registers the window class.
//
//  COMMENTS:
//
//    This function and its usage is only necessary if you want this code
//    to be compatible with Win32 systems prior to the 'RegisterClassEx'
//    function that was added to Windows 95. It is important to call this function
//    so that the application will get 'well formed' small icons associated
//    with it.
//
ATOM MyRegisterClass(HINSTANCE hInstance)
{
WNDCLASSEX wcex;

wcex.cbSize = sizeof(WNDCLASSEX);

wcex.style= CS_HREDRAW | CS_VREDRAW;
wcex.lpfnWndProc= (WNDPROC)WndProc;
wcex.cbClsExtra= 0;
wcex.cbWndExtra= 0;
wcex.hInstance= hInstance;
wcex.hIcon= LoadIcon(hInstance, (LPCTSTR)IDI_VIEW);
wcex.hCursor= LoadCursor(NULL, IDC_ARROW);
wcex.hbrBackground= (HBRUSH)(COLOR_WINDOW+1);

wcex.lpszMenuName= NULL;
wcex.lpszClassName= szWindowClass;
wcex.hIconSm= LoadIcon(wcex.hInstance, (LPCTSTR)IDI_SMALL);

return RegisterClassEx(&wcex);
}

//
//   FUNCTION: InitInstance(HANDLE, int)
//
//   PURPOSE: Saves instance handle and creates main window
//
//   COMMENTS:
//
//        In this function, we save the instance handle in a global variable and
//        create and display the main program window.
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
   HWND hWnd;

   hInst = hInstance; // Store instance handle in our global variable

   hWnd = CreateWindow(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
      CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);
   g_Hwnd=hWnd;

   if (!hWnd)
   {
      return FALSE;
   }

   ShowWindow(hWnd, nCmdShow);
   UpdateWindow(hWnd);

   return TRUE;
}

//
//  FUNCTION: WndProc(HWND, unsigned, WORD, LONG)
//
//  PURPOSE:  Processes messages for the main window.
//
//  WM_COMMAND- process the application menu
//  WM_PAINT- Paint the main window
//  WM_DESTROY- post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
int wmId, wmEvent;
PAINTSTRUCT ps;
HDC hdc;
TCHAR szHello[MAX_LOADSTRING];
LoadString(hInst, IDS_HELLO, szHello, MAX_LOADSTRING);
char strLogin[20];
char strPass[20];

switch (message)
{
case WM_COMMAND:
wmId    = LOWORD(wParam);
wmEvent = HIWORD(wParam);
// Parse the menu selections:
switch (wmId)
{

case 1:
GetWindowText(g_TBLogin,strLogin,20);
GetWindowText(g_TBPass,strPass,20);
if ((strcmp(strLogin,"admin")!=0)||(strcmp(strPass,"admin")!=0))
{
MessageBox(g_Hwnd,"用户名或密码错误","提示",MB_OK);
}
break;
default:
   return DefWindowProc(hWnd, message, wParam, lParam);
}
break;
case WM_CREATE:
{

g_TBLogin=CreateWindow("EDIT",NULL,WS_CHILD|WS_VISIBLE|WS_BORDER|ES_LEFT ,300,200,80,20,g_Hwnd,(HMENU)10,hInst,NULL);
g_TBPass=CreateWindow("EDIT",NULL,WS_CHILD|WS_VISIBLE|WS_BORDER|ES_LEFT,300,230,80,20,g_Hwnd,(HMENU)20,hInst,NULL);
g_Button=CreateWindow("Button","登录",WS_CHILD|WS_VISIBLE|BS_PUSHBUTTON,320,250,40,20,g_Hwnd,(HMENU)1,hInst,NULL);
//ShowWindow(g_Button,SW_SHOWNORMAL);
break;
}
case WM_PAINT:

hdc = BeginPaint(hWnd, &ps);
// TODO: Add any drawing code here...
RECT rt;
GetClientRect(hWnd, &rt);

//DrawText(hdc, szHello, strlen(szHello), &rt, DT_CENTER);
EndPaint(hWnd, &ps);
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}
[解决办法]
首先你地确定一下WM_CREATE是在什么时候触发的，我的理解是在主窗口创建的时候。如果主窗口还没创建出来，你的子窗口肯定创建不出来！
[解决办法]
没有初始化公用控件库
InitCommontrol()
[解决办法]
WM_CREATE 中, g_Hwnd 还未被赋值,

WM_CREATE 中, 字窗口的父窗口, 直接使用传入的 HWND 就行了.

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WM_CREATE讯息中创建控件不显示