ADOConnection.ConnectionString如何动态改变？

Question

DataModule里有个ADOConnection连接sqlserver ，
在form_main里
DM.ADOConnection1.Close;
DM.ADOConnection1.Connected:=false;
DM.ADOConnection1.ConnectionString:='Provider=SQLOLEDB.1;Password=test;Persist Security Info=True;User ID=test;Initial Catalog=fbc;Data Source=172.18.1.29';
DM.ADOConnection1.Connected:=true;
DM.ADOConnection1.open；怎么报错
‘Access violation at address ...............read od address 00000060’

Answer 1

conn.ConnectionString :='Provider=MSDASQL.1;Extended Properties="DRIVER=SQL Server;SERVER=IP;UID=用户;PWD=密码;Network=DBMSSOCN;Address=IP,1433"';

Answer 2

DM.ADOConnection1.Connected:=false;
DM.ADOConnection1.ConnectionString:='Provider=SQLOLEDB.1;Password=test;Persist Security Info=True;User ID=test;Initial Catalog=fbc;Data Source=172.18.1.29';
DM.ADOConnection1.Connected:=true;

Answer 3

好象DM.ADOConnection1.open；是多余的呀。

Answer 4

执行如下程序并填入一个错误的数据库ip，为什么要等待大约45秒才能timeout，在哪里设置timeout时间啊？try      DM.ADOConnection1.ConnectionString:='Provider=SQLOLEDB.1;Password=test;Persist Security Info=True;User ID=test;Initial Catalog=table1;Data Source=172.18.1.22';
      DM.ADOConnection1.ConnectionTimeout:=3;
      
      DM.ADOConnection1.Connected:=true;
   except
        showmessage('connection time out');
end;