public CenterWindow(IntPtr hOwner)
{
this.hOwner = hOwner;
this.cbtHook = new CbtHook();
cbtHook.WindowActivate += new CbtHook.CbtEventHandler(WndActivate);
cbtHook.Install();
}
public void Dispose()
{
if (wndProcRetHook != null)
{
wndProcRetHook.Uninstall();
wndProcRetHook = null;
}
if (cbtHook != null)
{
cbtHook.Uninstall();
cbtHook = null;
}
}
public void WndActivate(object sender, CbtEventArgs e)
{
IntPtr hMsgBox = e.wParam;
// try to find a howner for this message box
if (hOwner == IntPtr.Zero)
{
hOwner = Win32.Function.GetActiveWindow();
}
// get the MessageBox window rect
Win32.RECT rectDlg = new Win32.RECT();
Win32.Function.GetWindowRect(hMsgBox, ref rectDlg);
// get the owner window rect
Win32.RECT rectForm = new Win32.RECT();
Win32.Function.GetWindowRect(hOwner, ref rectForm);
// get the biggest screen area
Rectangle rectScreen = TrueScreenRect;
// if no parent window, center on the primary screen
if (rectForm.right == rectForm.left)
{
rectForm.right = rectForm.left = Screen.PrimaryScreen.WorkingArea.Width / 2;
}
if (rectForm.bottom == rectForm.top)
{
rectForm.bottom = rectForm.top = Screen.PrimaryScreen.WorkingArea.Height / 2;
}
// center on parent
int dx = ((rectDlg.left + rectDlg.right) - (rectForm.left + rectForm.right)) / 2;
int dy = ((rectDlg.top + rectDlg.bottom) - (rectForm.top + rectForm.bottom)) / 2;
rect = new Rectangle(
rectDlg.left - dx,
rectDlg.top - dy,
rectDlg.right - rectDlg.left,
rectDlg.bottom - rectDlg.top);
// place in the screen
if (rect.Right > rectScreen.Right)
{
rect.Offset(rectScreen.Right - rect.Right, 0);
}
if (rect.Bottom > rectScreen.Bottom)
{
rect.Offset(0, rectScreen.Bottom - rect.Bottom);
}
if (rect.Left < rectScreen.Left)
{
rect.Offset(rectScreen.Left - rect.Left, 0);
}
if (rect.Top < rectScreen.Top)
{
rect.Offset(0, rectScreen.Top - rect.Top);
}
if (e.IsDialog)
{
// do the job when the WM_INITDIALOG message returns
wndProcRetHook = new WndProcRetHook(hMsgBox);
wndProcRetHook.WndProcRet += new WndProcRetHook.WndProcEventHandler(WndProcRet);
wndProcRetHook.Install();
}
else
{
Win32.Function.MoveWindow(hMsgBox, rect.Left, rect.Top, rect.Width, rect.Height, 1);
}
// uninstall this hook
WindowsHook wndHook = (WindowsHook)sender;
Debug.Assert(cbtHook == wndHook);
cbtHook.Uninstall();
cbtHook = null;
}
