Ssrs custom data processing extension error in c#

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Data;
using System.Data.SqlClient;
using Microsoft.ReportingServices.DataProcessing;
using System.Diagnostics;
using System.Text.RegularExpressions;
using System.Configuration;

namespace DataBaseDPE
{  
    public class DBConnection:Microsoft.ReportingServices.DataProcessing.IDbConnectionExtension
    {
        //private string mconnstring;
        private string localname = "Database Connection";
        //private ConnectionState mState = ConnectionState.Open;
        private string m_sqlConnection1;
        public System.Data.SqlClient.SqlConnection sqlConnection1;
        
        public DBConnection()
        {
            Debug.WriteLine("DataSetConnection: Default Constructor");
        }
        public DBConnection(string Dconnection)
        {
            Debug.WriteLine("DataSetConnection Constructor overloaded with Connection String ");
            m_sqlConnection1 = Dconnection;

        }

        public Microsoft.ReportingServices.DataProcessing.IDbTransaction BeginTransaction()
        {
            throw new NotImplementedException();
        }

        
        public string ConnectionString
        {
            get
            {
                return m_sqlConnection1;
                
            }
            set
            {
                m_sqlConnection1 = "Data Source=localhost;Initial Catalog=test;Integrated Security=SSPI;";
            }
        }

        public int ConnectionTimeout
        {
            get
            {
                return 0;
            }
        }

        public Microsoft.ReportingServices.DataProcessing.IDbCommand CreateCommand()
        {
            return (new DBCommand(this));
        }

        public void Open()
        {
            Debug.WriteLine("IDBConnection.Open");

            sqlConnection1 = new SqlConnection(m_sqlConnection1);
            sqlConnection1.Open();
        }


        public void Close()
        {
            Debug.WriteLine("IDBConnection.Close()");

            sqlConnection1.Close();
        }
             
               
        public string LocalizedName
        {
            get 
            { 
                return localname; 
            }
            set 
            { 
                localname = value; 
            }
        }

        public void SetConfiguration(string configuration)
        {
            
                SqlConnection sqlconn = new SqlConnection("Data Source=localhost;Initial Catalog=test;Integrated Security=SSPI;");
            
            
        }
        public void Dispose()
        {

        }
        public string Impersonate
        { get; set; }

        public bool IntegratedSecurity
        { get; set; }

        public string Password
        { get; set; }

        public string UserName
        { get; set; }
    }

}

using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.ReportingServices.DataProcessing;
using System.Data.SqlClient;
using System.Diagnostics;

namespace DataBaseDPE
{
    public class DBCommand : Microsoft.ReportingServices.DataProcessing.IDbCommand
    {
        readonly DBConnection mconnection;
        private string mCmdText = "select id,name,location from test";
        private int mCmdTimeOut = 30;

        public DBCommand(DBConnection aConnection)
        {
            Debug.WriteLine("Command : Entering  constructor DataSetCommand(DataSetConnection aConnection)");
            mconnection = aConnection;
        }
        
               
        public DBCommand(string CmdText)
        {
            mCmdText = CmdText;
        }
        
        
        public void Cancel()
        {
            Debug.WriteLine("IDBCommand.Cancel");
            throw (new NotSupportedException("IDBCommand.Cancel currently not supported"));
        }

        public string CommandText
        {
            get
            {
                return mCmdText;
            }
            set
            {
                mCmdText = value;
            }
        }

        public int CommandTimeout
        {
            get
            {
                return mCmdTimeOut;
            }
            set
            {
                mCmdTimeOut = value;
            }
        }

        public CommandType CommandType
        {
            get
            {
                Debug.WriteLine("IDBCommand.CommandType: Get : ");
                return (CommandType.StoredProcedure);
            }
            set
            {
                Debug.WriteLine("IDBCommand.CommandType: Set");
                if (value != CommandType.StoredProcedure)
                {
                    throw (new NotSupportedException("Only CommandType.StoredProcedure is supported."));
                }
            }
        }

        public IDataParameter CreateParameter()
        {
            return (null);
        }

        public class MySqlDataReader:IDataReader
        {
            private System.Data.IDataReader sourceDataReader;
            private System.Data.DataTable dt;
            private System.Data.DataSet ds;
            private int fieldCount = 0;
            private string fieldName;
            private int fieldOrdinal;
            private Type fieldType;
            private object fieldValue;
            private int currentRow = 0;

            public MySqlDataReader(System.Data.IDataReader datareader)
            {
                this.sourceDataReader = datareader;
            }

            public MySqlDataReader(System.Data.DataTable dt)
            {
                // TODO: Complete member initialization
                
                this.dt = dt;
                
            }

            public MySqlDataReader(System.Data.DataSet ds)
            {
                // TODO: Complete member initialization
                this.ds = ds;
            }
            public int FieldCount
            {
                get
                {
                    fieldCount = ds.Tables[0].Columns.Count;
                    return fieldCount;
                }
                
            }

            public Type GetFieldType(int i)
            {
                fieldType =
               ds.Tables[0].Columns[i].DataType;
                return fieldType;
            }

            public string GetName(int i)
            {
                fieldName = ds.Tables[0].Columns[i].ColumnName;
                return fieldName;
            }

            public int GetOrdinal(string name)
            {
                fieldOrdinal =
               ds.Tables[0].Columns[name].Ordinal;
                return fieldOrdinal;
            }

            public object GetValue(int i)
            {
                fieldValue =
               ds.Tables[0].Rows[this.currentRow][i];
                return fieldValue;
            }

            public bool Read()
            {
                currentRow++;
                if (currentRow >= ds.Tables[0].Rows.Count)
                {
                    return (false);
                }
                else
                {
                    return (true);
                }
            }

            public void Dispose()
            {
                
            }
        
        }


        public IDataReader ExecuteReader(CommandBehavior behavior)
        {
            string query = "SampleSP";
            SqlConnection readerconn = new SqlConnection("Data Source=localhost;Initial Catalog=test;Integrated Security=SSPI");
            SqlCommand readercmd = new SqlCommand(query);

            
                readerconn.Open();
                readercmd = readerconn.CreateCommand();
                readercmd.CommandText = query;
                readercmd.CommandType = System.Data.CommandType.StoredProcedure;
                //SqlDataReader TestReader;
                //TestReader = readercmd.ExecuteReader();
                //TestReader.Close();
                readerconn.Close();
               
                SqlDataAdapter adapter = new SqlDataAdapter(query,readerconn);
                
                readerconn.Open();
                adapter.SelectCommand = readercmd;
                
                System.Data.DataTable dt = new System.Data.DataTable();
                adapter.Fill(dt);
                System.Data.DataSet ds = new System.Data.DataSet();
                adapter.Fill(ds);                
                return new MySqlDataReader(ds);

               
        }

        public IDataParameterCollection Parameters
        {
            get { return (null); }
        }

        public IDbTransaction Transaction
        {
            get
            {
                return (null);
            }
            set
            {
                throw new NotImplementedException();
            }
        }

        public void Dispose()
        {
            
        }
       
    }
}