function Copy2(aStr: string; Index: integer; Count: integer): string;
var
ws: WideString;
begin
ws:= aStr;
Result:= Copy(ws, Index, Count);
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
Edit1.Text:= 'Hello老外们!';
ShowMessage(Copy2(Edit1.Text, 1, 7));
end;