为web.config写入数据库连接字符串的方法

    1.写入连接字符串


 protected void Page_Load(object sender, EventArgs e)




    

{


        if (!Page.IsPostBack)




        

{


            


            // Create a new ConnectionStringSettings object and populate it


            ConnectionStringSettings conn = new ConnectionStringSettings();


            conn.ConnectionString = 


                 "Server=localhost;User ID=sa;Password=123456; " + 


                 "Database=Northwind;Persist Security Info=True";


            conn.Name = "AppConnectionString2";


            conn.ProviderName = "System.Data.SqlClient";




            // Add the new connection string to the web.config


            Configuration config = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration("example");


            config.ConnectionStrings.ConnectionStrings.Add(conn);


            config.Save();


        }


    }

2.修改连接字符串


protected void Page_Load(object sender, EventArgs e)




    

{


        // Retrieve an existing connection string into a Connection String Builder


        System.Data.SqlClient.SqlConnectionStringBuilder builder = new


            System.Data.SqlClient.SqlConnectionStringBuilder();




        // Change the connection string properties


        builder.DataSource = "localhost";


        builder.InitialCatalog = "Northwind1";


        builder.UserID = "sa";


        builder.Password = "password";


        builder.PersistSecurityInfo = true;




        // Save the connection string back to the web.config


        Configuration config = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration("/Chapter11");


        config.ConnectionStrings.ConnectionStrings["AppConnectionString1"].ConnectionString =


            builder.ConnectionString;


        config.Save();


    }