CreateWindow创建的窗口中输出文字，如何刷新？

Question

附件程序中是原码!
点鼠标左键时会在窗口中输出“程序员之家”，但是一旦最小化后恢复或是用其它窗口遮挡住后移出，“程序员之家”就消失了。
如何才能刷新窗口请各位指教？//WinMain.cpp#include <windows.h>
#include <stdio.h>LRESULT CALLBACK WinSunProc(
  HWND hwnd,      // handle to window
  UINT uMsg,      // message identifier
  WPARAM wParam,  // first message parameter
  LPARAM lParam   // second message parameter
);int WINAPI WinMain(
  HINSTANCE hInstance,      // handle to current instance
  HINSTANCE hPrevInstance,  // handle to previous instance
  LPSTR lpCmdLine,          // command line
  int nCmdShow              // show state
)
{
WNDCLASS wndcls;
wndcls.cbClsExtra=0;
wndcls.cbWndExtra=0;
wndcls.hbrBackground=(HBRUSH)GetStockObject(BLACK_BRUSH);
wndcls.hCursor=LoadCursor(NULL,IDC_CROSS);
wndcls.hIcon=LoadIcon(NULL,IDI_ERROR);
wndcls.hInstance=hInstance;
wndcls.lpfnWndProc=WinSunProc;
wndcls.lpszClassName="sunxin2006";
wndcls.lpszMenuName=NULL;
wndcls.style=CS_HREDRAW | CS_VREDRAW;
RegisterClass(&wndcls); HWND hwnd;
hwnd=CreateWindow("sunxin2006","http://www.sunxin.org",WS_OVERLAPPEDWINDOW,
0,0,600,400,NULL,NULL,hInstance,NULL); ShowWindow(hwnd,SW_SHOWNORMAL);
UpdateWindow(hwnd); MSG msg;
while(GetMessage(&msg,NULL,0,0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return msg.wParam;
}LRESULT CALLBACK WinSunProc(
  HWND hwnd,      // handle to window
  UINT uMsg,      // message identifier
  WPARAM wParam,  // first message parameter
  LPARAM lParam   // second message parameter
)
{
switch(uMsg)
{
case WM_CHAR:
char szChar[20];
sprintf(szChar,"char code is %d",wParam);
MessageBox(hwnd,szChar,"char",0);
break;
case WM_LBUTTONDOWN:
HDC hdc;
hdc=GetDC(hwnd);
TextOut(hdc,0,50,"程序员之家",strlen("程序员之家"));
//ReleaseDC(hwnd,hdc);
break;
case WM_PAINT:
HDC hDC;
PAINTSTRUCT ps;
hDC=BeginPaint(hwnd,&ps);
TextOut(hDC,0,0,"http://www.sunxin.org",strlen("http://www.sunxin.org"));
EndPaint(hwnd,&ps);
break;
case WM_CLOSE:
DestroyWindow(hwnd);
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hwnd,uMsg,wParam,lParam);
}
return 0;
}

Answer 1

放到WM_PAINT消息处理里。LRESULT CALLBACK WinSunProc(
HWND hwnd,      // handle to window
UINT uMsg,      // message identifier
WPARAM wParam,  // first message parameter
LPARAM lParam  // second message parameter
)
{
static bShow = FALSE;
switch(uMsg)
{
case WM_CHAR:
char szChar[20];
sprintf(szChar,"char code is %d",wParam);
MessageBox(hwnd,szChar,"char",0);
break;
case WM_LBUTTONDOWN:
bShow = TRUE;
break;
case WM_PAINT:
HDC hDC;
PAINTSTRUCT ps;
hDC=BeginPaint(hwnd,&ps);
TextOut(hDC,0,0,"http://www.sunxin.org",strlen("http://www.sunxin.org"));
if (bShow)
TextOut(hdc,0,50,"程序员之家",strlen("程序员之家")); EndPaint(hwnd,&ps);
break;
case WM_CLOSE:
DestroyWindow(hwnd);
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hwnd,uMsg,wParam,lParam);
}
return 0;
}

Answer 2

static BOOL bShow = FALSE;

Answer 3

一楼的正确.WM_PAINT消息作用就是重绘窗口,所以将要输出文本代码放在该消息中!

Answer 4

所有的输出工作都应该放到WM_PAINT消息的处理部分中

Answer 5

窗口刷新时会收到WM_PAINT消息，响应这个消息绘制的东西就不会被刷掉。参考1楼代码。

Answer 6

加下面代码就好了case WM_LBUTTONDOWN:
bShow = TRUE;
InvalidateRect(hwnd, NULL, TRUE);
return 0 ;