1.如何寫出由Button按一下啟動的跑馬燈?
2.以下的程式如何設Edit的跑馬燈開始點和終點?(就是Edit 加大後字串跑出去後就不見,不然就是跑到一半就跑回來)

void __fastcall TForm1::Button1Click(TObject *Sender)
{
Timer1->Interval=1000;
Edit1->Text="ABCD";
Edit1->Font->Pitch=fpFixed;
}
//---------------------------------------------------------------------------

void __fastcall TForm1::Timer1Timer(TObject *Sender)
{
int ratio,diff,ch;
String s=Edit1->Text;
Edit1->Width;
s.Length();
ratio=Edit1->Font->Size
*72/Edit1->Font->PixelsPerInch;
diff=Edit1->Width-s.Length()*ratio;
if(diff)
{for(int i=0; i s =" ";
Edit1->Text=s;
}
Edit1->Text=s.SubString(3,s.Length()-2) s.SubString(1,2);
}