Custom list adapter Xamarin.Android and direct SQL connection

MainActivity.cs

using Android.App;
using Android.Widget;
using Android.OS;
using System.Data.SqlClient;
using System.Collections.Generic;

namespace MyAndroid
{
    public class PostOnFirstPage
    {
        public string Id { get; set; }
        public string Title { get; set; }
        public string DateTime { get; set; }
    }
    [Activity(Label = "MyAndroid", MainLauncher = true, Icon = "@drawable/icon")]
    public class MainActivity : Activity
    {

        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.Main);


            SqlConnection con = new SqlConnection();
            con.ConnectionString = About.ConnectionString;
            con.Open();
            SqlCommand com = new SqlCommand();
            com.Connection = con;
            com.CommandText = "SELECT TOP 20 Id, Title, [Date] FROM [Post] ORDER BY [Date] DESC";
            SqlDataReader data = com.ExecuteReader();

            List<PostOnFirstPage> myPosts = new List<PostOnFirstPage>();

            while (data.Read())
            {
                myPosts.Add(new PostOnFirstPage
                {
                    Title = data["Title"].ToString(),
                    DateTime = data["Date"].ToString()
                });
            }

            if (myPosts.Count == 0)
            {
                Toast.MakeText(this, "هیچ پستی دریافت نشد", ToastLength.Long).Show();
            }
            else
            {
                ListView l1 = FindViewById<ListView>(Resource.Id.listView1);
                l1.Adapter = new RexaAdapter1(this, myPosts);
                l1.ItemClick += L1_ItemClick;
            }

        }

        private void L1_ItemClick(object sender, AdapterView.ItemClickEventArgs e)
        {
            // throw new System.NotImplementedException();
        }
    }
}

RexaAdapter1.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Java.Lang;

namespace MyAndroid
{
    class RexaAdapter1 : BaseAdapter
    {
        List<PostOnFirstPage> items;
        Activity context;
        public RexaAdapter1(Activity context, IEnumerable<PostOnFirstPage> items) : base()
        {
            this.context = context;
            this.items = items.ToList();
        }

        public override int Count
        {
            get
            {
                return items.Count();
            }
        }

        public override Java.Lang.Object GetItem(int position)
        {
            return items[position].Title;
        }

        public override long GetItemId(int position)
        {
            return position;
        }

        public override View GetView(int position, View convertView, ViewGroup parent)
        {
            View view = convertView;
            if (view == null)
                 view = context.LayoutInflater.Inflate(Resource.Layout.RexaListItem1, null);
            view.FindViewById<TextView>(Resource.Id.textView1).Text = items[position].Title;
            view.FindViewById<TextView>(Resource.Id.textView2).Text = items[position].DateTime;
            return view;

        }
    }
}

RexaListItem1.axml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:minWidth="25px"
    android:minHeight="25px">
    <TextView
        android:text="Large Text"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/textView1" />
    <TextView
        android:text="Small Text"
        android:textAppearance="?android:attr/textAppearanceSmall"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/textView2" />
</LinearLayout>