下面代码的一些情况讨论

[boytan]

/*------------------------------------------------------------
HELLOWIN.C -- Displays "Hello, Windows 98!" in client area
(c) Charles Petzold, 1998
------------------------------------------------------------*/

#include <windows.h>

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = TEXT ("HelloWin") ;
HWND hwnd ;
MSG msg ;
WNDCLASS wndclass ;

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

if (!RegisterClass (&wndclass))
{
MessageBox (NULL, TEXT ("This program requires Windows NT!"),
szAppName, MB_ICONERROR) ;
return 0 ;
}

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) ;
}
return msg.wParam ;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
HDC hdc ;
PAINTSTRUCT ps ;
RECT rect ;

switch (message)
{
case WM_CREATE:
return 0 ;
case WM_PAINT:
hdc = CreateDC(TEXT("DISPLAY"),NULL,NULL,NULL);
TextOut(hdc,0,0,TEXT("HELLO WORLD!"),lstrlen(TEXT("HELLO WORLD!")));
ValidateRect(hwnd,NULL);
UpdateWindow (hwnd) ;
DeleteDC(hdc);
return 0 ;
case WM_DESTROY:
PostQuitMessage (0) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}
会在屏幕的左上角产生一段文字，但是我用窗口遮住一部分后
文字不会恢复（如何恢复？）
窗口在移动时也不会恢复，但是我改变窗口大小可以恢复，请问为什么？
我是一个初学者，只为学东西，一定会给分的。

[a_kun]

ValidateRect(hwnd,NULL);
UpdateWindow (hwnd) ;
这两句改成BeginPaint和EndPaint

[a_kun]

请用wm_paint的标准写法

[golden_silence]

WM_PAINT消息是在窗口状态发生变化时（如：最大化，最小化，改变窗口大小，或用其他窗口覆盖本窗口等，不包括移动窗口）由WINDOWS系统发送给窗口的，所以你移动窗口覆盖文字时并没有触发WM_PAINT消息处理函数

[boytan]

那么移动窗口是什么消息？

[boytan]

谢谢golden_silence,现在马上给分