Android FragmentActivity findviewbyid（）在OnCreate中为null

Question

当我们重新启动应用程序崩溃后，由于FindViewById返回null，应用程序在此活动中崩溃，直到我们必须卸载该应用程序

我有这段代码：

public class StartupScreenActivity : FragmentActivity
{
    #region Fields

    private Button btnSignIn, btnIamNew;

    private AutoScrollViewPager aScrollViewPager;
    public HomePagerFragmentAdaptor hAdapter;
    public PageIndicator nIndicator;

    #endregion

    protected override void OnCreate (Bundle bundle)
    {
        base.OnCreate (bundle);
        RequestWindowFeature (WindowFeatures.NoTitle);
        SetContentView (Resource.Layout.StartupScreenLayout);

        #region Object initializer

        hAdapter = new HomePagerFragmentAdaptor (SupportFragmentManager);
        aScrollViewPager = FindViewById<AutoScrollViewPager> (Resource.Id.pager);
        nIndicator = FindViewById <CirclePageIndicator> (Resource.Id.indicator);

        btnSignIn = FindViewById<Button> (Resource.Id.SignIn);
        btnIamNew = FindViewById<Button> (Resource.Id.IAmNew);

        #endregion

        #region Apply Font

        btnSignIn.SetTypeface (FontFactory.GetFontFocoRG(this),TypefaceStyle.Normal);
        btnIamNew.SetTypeface (FontFactory.GetFontFocoRG(this),TypefaceStyle.Normal);

        #endregion

        #region Calling Methods

        aScrollViewPager.Adapter = hAdapter;
        aScrollViewPager.startAutoScroll();
        nIndicator.SetViewPager (aScrollViewPager);

        #endregion

        #region Event Handler 

        btnSignIn.Click += SignInOnClick;
        btnIamNew.Click += IamNewOnClick;
        #endregion
    } 

    protected override void OnResume ()
    {
        base.OnResume ();
        aScrollViewPager.startAutoScroll();
    }

    private void IamNewOnClick (object sender, EventArgs e)
    {
        aScrollViewPager.stopAutoScroll();
        this.LaunchActivity (typeof(GetInvitedActivity));
    }

    public void SignInOnClick (object sender, EventArgs e)
    {
        aScrollViewPager.stopAutoScroll();
        (this as Activity).LaunchActivity (typeof(LoginActivity));
    }
    public override void OnBackPressed()
    {
        Intent intent = new Intent(Intent.ActionMain);
        intent.AddCategory(Intent.CategoryHome);
        intent.SetFlags(ActivityFlags.ClearTop);

        StartActivity(intent);
        Finish();
    }
}