问题:

Inside an MDI form is a client area that hosts the mdi child forms. How do I find out how big that area is? The best I can come up with so far is finding the total size of the parent's potential client area (mdiparent.ClientRectangle) and then subtracting off the sizes of components like toolbars, etc that take away from the client area. Is there a better way?

回答1:

There is no property on a form that gives you access to the MDI client window. But you can find it back like this:

public MdiClient GetMdiClientWindow() {
  foreach (Control ctl in this.Controls) {
    if (ctl is MdiClient) return ctl as MdiClient;
  }
  return null;
}

From there, just use its Size property.

回答2:

Here's a variant of that code in vb.net:

Public Function GetMdiClientWindowSize() As Size
    For Each ctl As Control In Me.MdiParent.Controls
        If TypeOf ctl Is MdiClient Then
            Return ctl.Size
        End If
    Next
    Return Nothing
End Function