1 <?xml version="1.0" encoding="utf-8" ?>
 2 <configuration>
 3   <connectionStrings>
 4     <!--数据库认证-->
 5     <add name="Database1ConnectionString"
 6          connectionString="Data Source=DBServerName1;Initial Catalog=AdventureWorks2008;User ID=sa;Password=abc123"
 7          providerName="System.Data.SqlClient" />
 8     <!--Windows集成认证-->
 9     <add name="Database2ConnectionString"
10          connectionString="Data Source=DBServerName2;Initial Catalog=Northwind;Integrated Security=True"
11          providerName="System.Data.SqlClient" />
12 </configuration>

string conStr = System.Configuration.ConfigurationManager.ConnectionStrings["Database1ConnectionString"].ToString();