数据写不进数据库是什么原因,该怎么处理

using System;using System.Collections;using System.Configuration;using System.Data;using System.Linq;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.HtmlControls;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Xml.Linq;using System.Data.SqlClient;public partial class 注册页面 : System.Web.UI.Page{    protected void Page_Load(object sender, EventArgs e)    {    }    protected void Button1_Click(object sender, EventArgs e)    {              if (TextBox1.Text == "" || TextBox2.Text == "" || TextBox3.Text == "" || TextBox4.Text == "")        {            Label1.Text = "注册信息没有填写完整";        }        else        {            Response.Redirect("Default.aspx");        }        string ConnectionStr, insertStr;        //连接字符串        ConnectionStr = @"Data Source=.\SQLEXPRESS;AttachDbFilename=D:\360DATA\重要数据\我的文档\VISUAL STUDIO 2008\期末作业\APP_DATA\用户信息.MDF;        Integrated Security=True;Connect Timeout=30;User Instance=True";        //创建连接对象        SqlConnection sqlCon = new SqlConnection(ConnectionStr);        //建立插入命令字符串        insertStr = "INSERT INTO 注册信息保存 ([username],[password],[email]) VALUES (@username,@password,@email)";        try        {            //打开数据            sqlCon.Open();            if (sqlCon.State == ConnectionState.Open)            {                   //创建命令对象                SqlCommand sqlComm = new SqlCommand(insertStr, sqlCon);                sqlComm.Parameters.AddWithValue("@username", TextBox1.Text);                sqlComm.Parameters.AddWithValue("@password", TextBox2.Text);                sqlComm.Parameters.AddWithValue("@email", TextBox4.Text);                sqlComm.ExecuteNonQuery();            }        }        catch (SqlException exp)        {            Response.Write(exp.ToString());        }          finally        {            //关闭数据库            sqlCon.Close();        }          }}