delphi 帮忙看看这段程序
procedure Tform1.Edit1KeyDown(Sender: TObject; var Key: Word;
Shift: TShiftState);
begin
case Key of
VK_Return:
begin
Key := Word(#0); //这句是什么意思?
if ssShift in Shift then
Perform(WM_NextDLGCTL, 1, 0)
else
Perform(WM_NEXTDLGCTL, 0, 0); //两个perform是消息的意思,但第二位一个0,一个1都是什么意思?
end;
VK_UP:
begin
Key := Word(#0);
Perform(WM_NEXTDLGCTL, 1, 0);
end;
end;
end;
end;