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#include <windows.h>
LRESULT CALLBACK MainWndProc (HWND, UINT, WPARAM, LPARAM) ;
HINSTANCE hinst;
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = TEXT ("BlokOut1") ;
HWND hwnd ;
MSG msg ;
WNDCLASS wndclass ;
hinst=hInstance;
wndclass.style = CS_HREDRAW | CS_VREDRAW ;
wndclass.lpfnWndProc = MainWndProc ;
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 ("Program requires Windows NT!"),
szAppName, MB_ICONERROR) ;
return 0 ;
}
hwnd = CreateWindow (szAppName, TEXT ("Mouse Button Demo"),
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT,
NULL, NULL, hInstance, NULL) ;
ShowWindow (hwnd, iCmdShow) ;
UpdateWindow (hwnd) ;
while (GetMessage (&msg, NULL, 0, 0))
{
TranslateMessage (&msg) ;
DispatchMessage (&msg) ;
}
return msg.wParam ;
}
void DrawBoxOutline (HWND hwnd, POINT ptBeg, POINT ptEnd)
{
HDC hdc ;
hdc = GetDC (hwnd) ;
SetROP2 (hdc, R2_NOT) ;
SelectObject (hdc, GetStockObject (NULL_BRUSH)) ;
Rectangle (hdc, ptBeg.x, ptBeg.y, ptEnd.x, ptEnd.y) ;
ReleaseDC (hwnd, hdc) ;
}
LRESULT CALLBACK MainWndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
static BOOL fBlocking, fValidBox ;
static POINT ptBeg, ptEnd, ptBoxBeg, ptBoxEnd ;
HDC hdc ;
PAINTSTRUCT ps ;
switch (message)
{
case WM_LBUTTONDOWN :
ptBeg.x = ptEnd.x = LOWORD (lParam) ;
ptBeg.y = ptEnd.y = HIWORD (lParam) ;
DrawBoxOutline (hwnd, ptBeg, ptEnd) ;
SetCursor (LoadCursor (NULL, IDC_CROSS)) ;
fBlocking = TRUE ;
return 0 ;
case WM_MOUSEMOVE :
if (fBlocking)
{
SetCursor (LoadCursor (NULL, IDC_CROSS)) ;
DrawBoxOutline (hwnd, ptBeg, ptEnd) ;
//DrawBoxOutline (hwnd, ptBeg, ptEnd);
ptEnd.x = LOWORD (lParam) ;
ptEnd.y = HIWORD (lParam) ;
DrawBoxOutline (hwnd, ptBeg, ptEnd) ;
//DrawBoxOutline (hwnd, ptBeg, ptEnd) ;
}
return 0 ;
case WM_LBUTTONUP :
if (fBlocking)
{
DrawBoxOutline (hwnd, ptBeg, ptEnd) ;//白
ptBoxBeg = ptBeg ;
ptBoxEnd.x = LOWORD (lParam) ;
ptBoxEnd.y = HIWORD (lParam) ;
SetCursor (LoadCursor (NULL, IDC_ARROW)) ;
fBlocking = FALSE ;
fValidBox = TRUE ;
InvalidateRect (hwnd, NULL, TRUE) ;
}
return 0 ;
case WM_CHAR :
if (fBlocking & (wParam == '\x1B'))
{
DrawBoxOutline (hwnd, ptBeg, ptEnd) ;
SetCursor (LoadCursor (NULL, IDC_ARROW)) ;
fBlocking = FALSE ;
}
return 0 ;
case WM_PAINT :
hdc = BeginPaint (hwnd, &ps) ;
if (fValidBox)
{
SelectObject (hdc, GetStockObject (BLACK_BRUSH)) ;
Rectangle (hdc, ptBoxBeg.x, ptBoxBeg.y,
ptBoxEnd.x, ptBoxEnd.y) ;
}
if (fBlocking)
{
SetROP2 (hdc, R2_NOT) ;
SelectObject (hdc, GetStockObject (NULL_BRUSH)) ;
Rectangle (hdc, ptBeg.x, ptBeg.y, ptEnd.x, ptEnd.y) ;
}
EndPaint (hwnd, &ps) ;
return 0 ;
case WM_DESTROY :
PostQuitMessage (0) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}