var AWinControl:TPageControl; begin AWinControl := PageControl1; if frmAbout = nil then Exit; frmAbout.ManualDock(AWinControl, nil, alClient); frmAbout.Align := alClient; frmAbout.Show; end;
http://www.cnblogs.com/jxgxy/archive/2010/02/13/1668082.html
原文：http://www.cnblogs.com/findumars/p/4964833.html