using System;
using System.Data;
using System.Configuration;
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;
/// <summary>
///SQLServer 的摘要说明
/// </summary>
public class SQLServer
{
 public SQLServer()
 {
  //
  //TODO: 在此处添加构造函数逻辑
  //
 }
    /// <summary>
    /// 测试数据库连接
    /// </summary>
    /// <returns></returns>
    public bool TestConncect()
    {
        SqlConnection conn = new SqlConnection();
        conn.ConnectionString = "Data Source=.\\SQLExperss;Integrated Security=true; AttachDbFilename=|DataDirectory|\\Database.mdf;User Instance=true;";
        try
        {
            conn.Open();
            return (conn.State == ConnectionState.Open);
        }
        catch (SqlException ex)
        {
            return false;
        }
        finally
        {
            conn.Close();
        }
    }
}

using System;
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;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        SQLServer db = new SQLServer();
        bool isConncted=db.TestConncect();
        Response.Write(isConncted);
    }
}

以此连接显示False 错误 请大侠们教教我