你可在dxTreeView1的OnMouseDown事件中判斷(dxTreeView應該也有這事件)    procedure TfPtyAd11.dxTreeView1MouseDown(Sender: TObject;
  Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  Case dxTreeView1.GetHitTestInfoAt(X, Y) Of
    htOnItem : ....;  // 點在item上
    htAbove:...;//以下各個位置你可以試試看或看Help
    htBelow:...;
    htNowhere:...;
    htOnButton:...;
    htOnIcon:...;
    htOnIndent:...;
    htOnLabel:...;// 點在item的文字上
    htOnRight:...;
    htOnStateIcon:...;
    htToLeft:...;
    htToRight:...;
  End;
end;