为什么我的ONPAINT一加上就不见了static控件？

[kedengfeng]

#include<windows.h>

// Global Variables:
HINSTANCE hInst; // current instance
HWND hPic; // a rectangle for painting or writing

// Foward declarations of functions included in this code module:
ATOM MyRegisterClass(HINSTANCE hInstance);
BOOL InitInstance(HINSTANCE, int);
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

int APIENTRY WinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int nCmdShow)
{
MyRegisterClass(hInstance);

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

// Main message loop:
MSG msg;
while (GetMessage(&msg, NULL, 0, 0))
{
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(NULL,IDI_APPLICATION);
wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wcex.lpszMenuName = NULL;
wcex.lpszClassName = "KDF";
wcex.hIconSm = LoadIcon(NULL, IDI_APPLICATION);

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("KDF", "KDF", WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, 0, CW_USEDEFAULT, 0,
NULL, NULL, hInstance, NULL);

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_PAINT - Paint the main window
// WM_DESTROY - post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
PAINTSTRUCT ps;

switch (message)
{
case WM_CREATE:
hPic = CreateWindow("STATIC","STATIC",WS_CHILD|WS_VISIBLE|SS_GRAYRECT,
20,20,200,50,hWnd,NULL,(HINSTANCE)GetWindowLong(hWnd,GWL_HINSTANCE),NULL);
if(hPic){
ShowWindow(hPic,SW_SHOW);
UpdateWindow(hPic);
}else{
MessageBox(hWnd,"Create Child Window Err","Err",0);
}
break;
//{为什么下面语句一加上,那个hPic的Rectangle就不见了？
/*
case WM_PAINT:
BeginPaint(hPic, &ps);
RECT rt;GetClientRect(hPic, &rt);
SelectObject(ps.hdc,GetStockObject(LTGRAY_BRUSH));
SetBkColor (ps.hdc,RGB(255,0,0));
TextOut(ps.hdc,0,0,"Hello",5);
EndPaint(hPic, &ps);
break;
*/
//}by woodmen

case WM_DESTROY:
DestroyWindow(hPic);
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}

[wuchuncai]

很自然，WM_PAINT要刷新屏幕。

[wuchuncai]

而你又未重画你的rectangle