2D游戏编程4—Windows事件
windows消息传来的参数分解：
Parameterization:
fActive = LOWORD(wParam); // activation flag
fMinimized = (BOOL)HIWORD(wParam); // minimized flag
hwndPrevious = (HWND)lParam; // window handle
The Activation Flags for WM_ACTIVATE
Value
DescriptionWA_CLICKACTIVE
Activated by a mouse click.WA_ACTIVE
The window has been activated by some means other than the mouse, such as the keyboard interface.WA_INACTIVE
The window is being deactivated.
WinProc激活程序消息的处理：
case WM_ACTIVATE:
{
// test if window is being activated
if (LOWORD(wparam)!=WA_INACTIVE)
{
// application is being activated
} // end if
else
{
// application is being deactivated
} // end else} break;
Message: WM_CLOSE
case WM_CLOSE:
{
// display message box
int result = MessageBox(hwnd,
"Are you sure you want to close this application?",
"WM_CLOSE Message Processor",
MB_YESNO | MB_ICONQUESTION);// does the user want to close?
if (result == IDYES)
{
// call default handler
return (DefWindowProc(hwnd, msg, wparam, lparam));
} // end if
else // throw message away
return(0);} break;
Message: WM_SIZE
fwSizeType = wParam; // resizing flag
nWidth = LOWORD(lParam); // width of client area
nHeight = HIWORD(lParam); // height of client area
The fwSizeType flag indicates what kind of resizing just occurred
Value
DescriptionSIZE_MAXHIDE
Message is sent to all pop-up windows when some other window is maximized.SIZE_MAXIMIZED
Window has been maximized.SIZE_MAXSHOW
Message is sent to all pop-up windows when some other window has been restored to its former size.SIZE_MINIMIZED
Window has been minimized.SIZE_RESTORED
Window has been resized, but neither the SIZE_MINIMIZED nor SIZE_MAXIMIZED value applies.
处理代码：
case WM_SIZE:
{
// extract size info
int width = LOWORD(lparam);
int height = HIWORD(lparam);// get a graphics context
hdc = GetDC(hwnd);// set the foreground color to green
SetTextColor(hdc, RGB(0,255,0));// set the background color to black
SetBkColor(hdc, RGB(0,0,0));// set the transparency mode to OPAQUE
SetBkMode(hdc, OPAQUE);// draw the size of the window
sprintf(buffer,
"WM_SIZE Called - New Size = (%d,%d)", width, height);
TextOut(hdc, 0,0, buffer, strlen(buffer));// release the dc back
ReleaseDC(hwnd, hdc);} break;
Message: WM_MOVE
case WM_MOVE:
{
// extract the position
int xpos = LOWORD(lparam);
int ypos = HIWORD(lparam);// get a graphics context
hdc = GetDC(hwnd);// set the foreground color to green
SetTextColor(hdc, RGB(0,255,0));// set the background color to black
SetBkColor(hdc, RGB(0,0,0));// set the transparency mode to OPAQUE
SetBkMode(hdc, OPAQUE);// draw the size of the window
sprintf(buffer,
"WM_MOVE Called - New Position = (%d,%d)", xpos, ypos);
TextOut(hdc, 0,0, buffer, strlen(buffer));
// release the dc back
ReleaseDC(hwnd, hdc);} break;