使用ViewPager和TabLayout与Xamarin时出错

Question

我想在我的应用程序中添加一个点指示器，但是当我在线tabLayout.SetupWithViewPager(viewPager, true);时出现以下错误：

Java.Lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.ImageView

我已经尝试删除Resource.Designer.cs文件，但这并没有改变任何东西。我在代码中弄乱了什么吗？或者Xamarin每次构建应用程序时都不会重建R.java？该准则在GitHub上线。以下是viewPager所需的主要文件：

Main.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">
    <Toolbar
        android:minHeight="?android:attr/actionBarSize"
        android:background="?android:attr/colorPrimary"
        android:minWidth="25px"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/toolbar" />
    <android.support.v4.view.ViewPager
        android:id="@+id/pager"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:overScrollMode="never" />
    <android.support.design.widget.TabLayout
        android:id="@+id/tabs"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
</LinearLayout>

MainActivity.cs：

public class MainActivity : FragmentActivity
{
    ViewPager viewPager;
    TabLayout tabLayout;
    Input Input = new Input();
    Graphic Graphic = new Graphic();

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

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

        Toolbar toolbar = FindViewById<Toolbar>(Resource.Id.toolbar);
        toolbar.SetTitleTextColor(Android.Graphics.Color.White);
        SetActionBar(toolbar);

        ActionBar.Title = "TyCoDim";

        viewPager = (ViewPager) FindViewById(Resource.Id.pager);
        tabLayout = (TabLayout) FindViewById(Resource.Id.tabs);
        SetupViewPager(viewPager);
        tabLayout.SetupWithViewPager(viewPager, true);

        viewPager.PageSelected += ViewPager_PageSelected;
    }

    private void ViewPager_PageSelected(object sender, ViewPager.PageSelectedEventArgs e)
    {

    }

    private void SetupViewPager(ViewPager Pager)
    {
        Pager.OffscreenPageLimit = 2;

        PageAdapter adapter = new PageAdapter(SupportFragmentManager);
        adapter.AddFragment(Input, "Input");
        adapter.AddFragment(Graphic, "Graphic");

        Pager.Adapter = adapter;
    }
}

PagerAdapter.cs：

class PageAdapter : FragmentPagerAdapter
{
    private readonly List<Fragment> _fragments;
    private readonly List<string> _fragmentnames;

    public PageAdapter(FragmentManager fm) : base(fm)
    {
        _fragments = new List<Fragment>();
        _fragmentnames = new List<string>();
    }

    public override int Count
    {
        get { return _fragments.Count; }
    }
    public override Fragment GetItem(int position)
    {
        return _fragments[position];
    }

    public void AddFragment(Fragment fragment, string name)
    {
        if (fragment == null) return;
        _fragments.Add(fragment);
        _fragmentnames.Add(name);
    }

    public override ICharSequence GetPageTitleFormatted(int position)
    {
        return new Java.Lang.String(_fragmentnames[position]);
    }
}