ASP.NET与sql server 2008建立联系，调试老是出错，请高手指教！

public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
SqlConnection myConn = new SqlConnection();
myConn.Open();
string sqlStr = "select*from id";
SqlCommand myCmd = new SqlCommand(sqlStr, myConn);
SqlDataReader dr = myCmd.ExecuteReader();
while (dr.Read())
{
Response.Write(dr[1].ToString() + "
");
}
myConn.Close();
}
}
}

代码SqlConnection myConn = new SqlConnection();有问题
你这个连接对象根本就没指定连接字符串，有两个方法，一是调用你写的MyClass类 MyClass DbClass=new MyClass();
SqlConnection myConn =DbClass.GetConnection();
//下面的代码
另一个更直接:
SqlConnection myConn = new SqlConnection();
myConn.ConnectionString=ConfigurationManager.AppSettings["ConnectiongString"].ToString();
//下面的代码

SqlConnection myConn = new SqlConnection();
未将对象引用到实例
SqlConnection myConn = new SqlConnection(ConfigurationManager.ConnectionStrings["connStr"].ConnectionString);

你的连接字符串写错了,再改改你的连接字符串吧