【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