c# - 在执行更多查询时，我收到“不允许更改'ConnectionString'属性。”

class CommonConnection
{
    public class dStructure
    {
        public static string ConnectionString = "";
    }

    public SqlConnection Conn;
    #region "Connection Procedures"
    public string ConnectionString
    {
        get
        {
            string sConn = string.Empty;
            sConn = @"Server=ServerName;Initial Catalog=Database;User ID=userid;Password=password;";
            dStructure.ConnectionString = sConn;
            return dStructure.ConnectionString;

        }
    }

    public void cnOpen()
    {
        try
        {
            if (Conn == null)
            {
                Conn = new System.Data.SqlClient.SqlConnection();
            }
            if (Conn.State == ConnectionState.Open)
            {
                Conn.Close();
            }
            Conn.ConnectionString = ConnectionString;
            Conn.Open();
        }
        catch (SqlException e)
        {
            SqlConnection.ClearAllPools();
            throw e;
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

    public void cnClose()
    {
        try
        {
            if ((Conn != null))
            {
                if (Conn.State == ConnectionState.Open)
                {
                    Conn.Close();
                }
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }
        finally
        {
            Conn = null;
        }
    }
    #endregion

    public int ExecuteQuery(string strQuery, Int16 TimeOut = 30)
    {
        int RecordsAffected;
        SqlCommand cmd;
        try
        {
            cnOpen();
            cmd = new SqlCommand(strQuery, Conn);
            cmd.CommandTimeout = TimeOut;
            RecordsAffected = cmd.ExecuteNonQuery();

            return RecordsAffected;
        }
        catch (Exception ex)
        {
            throw ex;
        }
        finally
        {
            cnClose();
            cmd = null;
        }
    }
}

//尝试了以下另一个选项，

    public int ExecuteQuery(string strQuery, short TimeOut = 10)
    {
        SqlConnection NewConn = new SqlConnection();
        try
        {
            if (NewConn == null)
            {
                NewConn = new System.Data.SqlClient.SqlConnection();
            }
            if (NewConn.State == ConnectionState.Open)
            {
                NewConn.Close();
            }
            NewConn.ConnectionString = "Server=ServerName;Initial Catalog=Database;User ID=userid;Password=password;";
            NewConn.Open();

            return new SqlCommand(strQuery, NewConn)
            {
                CommandTimeout = ((int)TimeOut)
            }.ExecuteNonQuery();
        }
        catch (Exception ex)
        {
            throw ex;
        }
        finally
        {
            NewConn.Close();
        }
    }

但是仍然遇到同样的问题。
它的桌面应用程序是多线程的。但是，尽管对此增加了更多查询负载，但我却被禁止更改'ConnectionString'属性。连接的当前状态为打开。
请注意，并非每次我都遇到此问题时，才执行更多查询。

//更新2
根据另一个问题的建议，我尝试使用下面的代码，但问题仍然相同。

    public int ExecuteQuery(string strQuery, short TimeOut = 10)
    {
        int executeReader = 0;
        try
        {
            using (SqlConnection connection = new SqlConnection(@"Server=Server;Initial Catalog=DB;User ID=id;Password=Password;"))
            {
                try
                {
                    connection.Open();
                    SqlCommand command = new SqlCommand(strQuery, connection);
                    command.CommandType = CommandType.Text;
                    command.CommandTimeout = TimeOut;
                    executeReader = command.ExecuteNonQuery();
                }
                catch (Exception ex)
                {
                    throw ex;
                }
            }
            return executeReader;
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

如此处所建议，使用命令使用默认IDisposable，因此无需关闭连接。

最佳答案

尝试这个

类：

 public class CommonConnection
{
    String constr = System.Configuration.ConfigurationManager.ConnectionStrings["myconectionstring"].ConnectionString;
    public CommonConnection()
    {

        //
        // TODO: Add constructor logic here
        //
    }
    //Insert,Update,Delete....
    public int ExecuteNonQuery1(string str)
    {
        //String constr = System.Configuration.ConfigurationManager.ConnectionStrings["CommonConnection"].ConnectionString;

        SqlConnection con = new SqlConnection(constr);

        SqlCommand cmd = new SqlCommand(str, con);


        int result = 0;

        try
        {

            con.Open();
            result = cmd.ExecuteNonQuery();


            con.Close();
        }
        catch (Exception ex)
        {
            result = -1;
            try
            {
                if (con.State == ConnectionState.Open)
                {
                    con.Close();
                }
            }
            catch (Exception ex2)
            {
                // ErrHandler.WriteError(ex2.ToString());
            }
            // ErrHandler.WriteError(ex.ToString());
        }

        return result;

    }
}

ASPX.CS：

        SortedList s1 = new SortedList();
        s1.Add("@mode", "Update");
        s1.Add("@cid", ViewState["CategoryId"]);
        int a = sp.ExecuteNonQuerySP1("SP_Name", s1);
        if (a > 0)
        {
        }