procedure TForm1.EdtHeightClick(Sender: TObject);
begin
   EdtHeight.setfocus;
end;

然后为什么不行，无法获得焦点？
procedure TForm1.Button0Click(Sender: TObject);
begin

  if EdtHeight.Focused then
  begin
    EdtHeight.Text:= EdtHeight.Text+'0';
    EdtHeight.SelStart := Length(EdtHeight.Text);
  end;
   if EdtWeight.Focused then
   begin
  EdtWeight.Text:= EdtWeight.Text+'0';
  EdtWeight.SelStart := Length(EdtWeight.Text);
   end;
end;