【Demo 0022】改变窗体大小和位置

窗体有三个最基本的属性：位置，大小，Z-Order， Windows 对于改变窗体位置和大小这两个更常用提供了更简单的函数.

（一）改变窗体大小和位置

       BOOL MoveWindow(HWND hWnd, int x, int y, int nWidth, int nHeight, BOOL bRepaint)

        改变指定窗体的起始位置以及窗体大小，最后一个参数是改变是否重绘窗体

        以下代码演示了将窗体置桌面客户区中间，以及将控件置于窗体客户区中间并放大一倍

  

UINT nSrnWidth     = GetSystemMetrics ( SM_CXFULLSCREEN );
UINT nSrnHeight     = GetSystemMetrics ( SM_CYFULLSCREEN );

RECT rtWnd ;
GetWindowRect ( hWnd , & rtWnd );
UINT nWndWidth     = ( rtWnd . right - rtWnd . left );
UINT nWndHeight = ( rtWnd . bottom - rtWnd . top );
MoveWindow ( hWnd , ( nSrnWidth - nWndWidth ) / 2, ( nSrnHeight - nWndHeight ) / 2, nWndWidth , nWndHeight , TRUE );

HWND hBtnMove = GetDlgItem ( hWnd , wParam );
UINT nBtnWidth     = 200;
UINT nBtnHeight = 100;
MoveWindow ( hBtnMove , ( nWndWidth - nBtnWidth ) / 2, ( nWndHeight - nBtnHeight ) / 2, nBtnWidth , nBtnHeight , TRUE );

 

（二）改变窗体大小和位置触发的消息

        1.  WM_WINDOWPOSCHANGING
        2.  WM_WINDOWPOSCHANGED

        3.  WM_MOVE

        4.  WM_SIZE
        5.  WM_NCCALCSIZE

  

case WM_WINDOWPOSCHANGING :
{
     TCHAR szInfo [128];
     _stprintf ( szInfo , _T ( "Step %d:        WM_WINDOWPOSCHANGING\n" ), ++ nStep );
     OutputDebugString ( szInfo );
     break ;
}
case WM_WINDOWPOSCHANGED :
{
     TCHAR szInfo [128];
     _stprintf ( szInfo , _T ( "Step %d:        WM_WINDOWPOSCHANGED\n" ), ++ nStep );
     OutputDebugString ( szInfo );
     break ;
}
case WM_MOVE :
{
     TCHAR szInfo [128];
     _stprintf ( szInfo , _T ( "Step %d:        WM_MOVE\n" ), ++ nStep );
     OutputDebugString ( szInfo );
     break ;    
}
case WM_SIZE :
{
     TCHAR szInfo [128];
     _stprintf ( szInfo , _T ( "Step %d:        WM_SIZE\n" ), ++ nStep );
     OutputDebugString ( szInfo );
     break ;
}
case WM_NCCALCSIZE :
{
     TCHAR szInfo [128];
     _stprintf ( szInfo , _T ( "Step %d:        WM_NCCALCSIZE\n" ), ++ nStep );
     OutputDebugString ( szInfo );
     break ;
}

      程序启动时结果:

      Step 1:        WM_NCCALCSIZE
      Step 2:        WM_SIZE
      Step 3:        WM_MOVE
      Step 4:        WM_WINDOWPOSCHANGING
      Step 5:        WM_WINDOWPOSCHANGING
      Step 6:        WM_WINDOWPOSCHANGED

      移动窗体后结果：

Step 71:        WM_WINDOWPOSCHANGING
Step 72:        WM_WINDOWPOSCHANGED
Step 73:        WM_MOVE
Step 74:        WM_WINDOWPOSCHANGING
Step 75:        WM_WINDOWPOSCHANGED
Step 76:        WM_MOVE
Step 77:        WM_WINDOWPOSCHANGING
Step 78:        WM_WINDOWPOSCHANGED
Step 79:        WM_MOVE
Step 80:        WM_WINDOWPOSCHANGING

 

演示代码