C #Visual studio连接sql
左侧服务器资源管理器显示 数据连接成功,但为什么启动程序时调试，显示无法打开所请求的数据库  数据库用户登录失败






详细代码

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;
namespace Test13.ClsDB
{
    class ClsDBControl
    {
        private SqlConnection con;

        #region
        public SqlConnection ConDB()
        {
            con = new SqlConnection("server=WIN-01705070938;database=db_15;uid= 123 ;pwd=123;");
          if (con.State == ConnectionState.Closed)
            {
                con.Open();
            }
            return con;
        }
        #endregion

        public DataSet dsResult(int currentIndex)
        {
            int pageSize = 1;
            string orderSQL = "SELECT * FROM tb_People ORDER BY tb_PID";
            SqlDataAdapter adapter = new SqlDataAdapter(orderSQL, ConDB());
            DataSet dataSet = new DataSet("tb_People");
            adapter.Fill(dataSet, currentIndex, pageSize, "tb_People");
            return dataSet;
        }

        public int Max()
        {
            SqlCommand cmd = new SqlCommand("select count(*) from tb_people", ConDB());
            return int.Parse(cmd.ExecuteScalar().ToString());
        }
    }
}

错误详细信息 错误代码 ErrorCode=-2146232060
未处理 System.Data.SqlClient.SqlException
  Message=无法打开登录所请求的数据库 "db_15"。登录失败。
用户 '123' 登录失败。
  Source=.Net SqlClient Data Provider
  ErrorCode=-2146232060
  Class=11
  LineNumber=65536
  Number=4060
  Procedure=""
  Server=WIN-01705070938
  State=1
  StackTrace:
       在 System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)
       在 System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)
       在 System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)
       在 System.Data.SqlClient.SqlInternalConnectionTds.CompleteLogin(Boolean enlistOK)
       在 System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnection owningObject, Boolean withFailover)
       在 System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(String host, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, Int64 timerStart)
       在 System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance)
       在 System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance)
       在 System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection)
       在 System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options)
       在 System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject)
       在 System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject)
       在 System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject)
       在 System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)
       在 System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
       在 System.Data.SqlClient.SqlConnection.Open()
       在 Test13.ClsDB.ClsDBControl.ConDB() 位置 G:\C#实例\TM（视频讲解及实例源程序）\sl（实例源程序）\15\13\Test13\Test13\ClsDB\ClsDBControl.cs:行号 18
       在 Test13.ClsDB.ClsDBControl.Max() 位置 G:\C#实例\TM（视频讲解及实例源程序）\sl（实例源程序）\15\13\Test13\Test13\ClsDB\ClsDBControl.cs:行号 36
       在 Test13.Form1.Form1_Load(Object sender, EventArgs e) 位置 G:\C#实例\TM（视频讲解及实例源程序）\sl（实例源程序）\15\13\Test13\Test13\Form1.cs:行号 22
       在 System.Windows.Forms.Form.OnLoad(EventArgs e)
       在 System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
       在 System.Windows.Forms.Control.CreateControl()
       在 System.Windows.Forms.Control.WmShowWindow(Message& m)
       在 System.Windows.Forms.Control.WndProc(Message& m)
       在 System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       在 System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
  InnerException:
请大家帮我看看什么原因造成的