ListView没有显示（Xamarin）

Question

Screenprint.我正在关注this练习“Xamarin Android教程2创建ListView”。这是我的代码：

using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using System;
using System.Collections.Generic;

namespace ListViewTutorial
{
    [Activity(Label = "ListViewTutorial", MainLauncher = true, Icon = "@drawable/icon")]
    public class MainActivity : Activity
    {
        int count = 1;
        private List<string> mItems; // 1 Create a list
        private ListView mListView; // 3 Get the list view


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

            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.Main);
            mListView = FindViewById<ListView>(Resource.Id.myListView); // 4 Get the reference to the ListView

            mItems = new List<String>(); // 2 Instantiate the list and populate it
            mItems.Add("Bob");
            mItems.Add("Tom");
            mItems.Add("Jim");

            ArrayAdapter<string> adapter = new ArrayAdapter<string>(this, Android.Resource.Layout.SimpleListItem1, mItems); // 5 Instantiate the adapter

            mListView.Adapter = adapter; // 6
        }
    }
}

这是我的Main.axml文件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:minWidth="25px"
    android:minHeight="25px">
    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/myListView" />
</LinearLayout>

问题是我的ListView没有显示任何内容。我哪里错了？我相信我的代码与视频代码相同。