delphi套接字异常无法更改主机和端口的值

当我试图将端口和主机分配给delphi客户端套接字时,出现了一个异常“当套接字处于活动状态时无法更改值”。但我没有更改套接字。active:=true。有人能提出这个错误的可能原因吗。

procedure CreateSocket(add : pchar);
var
  port : integer;
  address : string;
  host : string;
  socket1 : TClientSocket;
begin  
  setstring(address,add,50);
  //showmessage(address) ;
  host := split(address,':');
  address := del(address,':');
  //showmessage(address);
  port := strtoint(address);

  socket1.port := port; //exception comes here
  socket1.host := host;

  showmessage('address assigned');

  connectionAttempt(Socket1);

  CheckDataArrival(socket1);
end;