我有一个片段（func getAllRowCount()->Int{
var rowCount = 0
for index in 0...self.tableView.numberOfSections-1{
rowCount += self.tableView.numberOfRows(inSection: index)
}
return rowCount
}
），其中包含工具栏中的两个标签。我在HomeFragment内使用ViewPager和FragmentStatePagerAdapter来制作可以在片段之间滑动。但是，第一个标签应显示托管HomeFragment和HomeFragment的片段（ViewPager）。第二个选项卡应该显示另一个名为PagerAdapter的片段。
现在我的问题是显示第二个标签，我确实可以从第一个标签滑动到第二个标签。但是第一个标签没有显示ChatFragment应该是的任何内容，它只是空的。
我已尝试在单独的项目中使用工具栏连接HomeFragment和ViewPager，并且在那里完美运行。但是，最大的区别在于PagerAdapter和ViewPager是在活动中托管的，而不是现在PagerAdapter和ViewPager托管在其中一个需要的碎片中要显示。
所以我认为PagerAdapter / ViewPager托管在一个也需要显示的片段中可能会有什么问题？
总而言之，我如何从需要显示的其中一个片段中托管ViewPager / FragmentStatePagerAdater？
有什么想法吗？如果不清楚，请告诉我。
编辑：正如 Stanislav Bondar 所指出的，这听起来有点像另一个post（如何将viewpager放入android中的片段？） 。但是，据我所知，OP想知道如何将ViewPager与嵌套片段一起使用。我没有嵌套片段，需要将ViewPager托管在一个片段中。。
编辑2：代码。
Home.axml：
PagerAdapterHomeFragment.cs
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/coordLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.AppBarLayout
android:id="@+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.design.widget.CollapsingToolbarLayout
android:id="@+id/collapsing_toolbar"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_scrollFlags="scroll|snap"
android:fitsSystemWindows="true"
app:contentScrim="?attr/colorPrimary">
<refractored.controls.CircleImageView
android:id="@+id/circleProfileImage"
android:layout_width="96dp"
android:layout_height="96dp"
android:src="@drawable/profile"
android:layout_marginTop="15dp"
android:layout_marginBottom="10dp"
android:layout_gravity="center"
app:civ_border_width="2dp"
app:civ_border_color="#FF0000"/>
<!--app:layout_collapseMode="pin" pins the icons when scrolling-->
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_height="wrap_content"
android:layout_width="match_parent"
app:layout_collapseMode="pin"
app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light">
<!--Toolbar title -->
<TextView
android:id="@+id/toolbar_title"
android:textStyle="bold"
android:textColor="@color/white"
android:textSize="18dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="start"/>
</android.support.v7.widget.Toolbar>
</android.support.design.widget.CollapsingToolbarLayout>
<!-- -->
<android.support.design.widget.TabLayout
android:id="@+id/tabLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabTextColor="@color/black"
app:tabSelectedTextColor="@color/gray"
app:tabIndicatorColor="@color/accent"
app:tabIndicatorHeight="6dp"
app:tabMode="fixed"
app:tabGravity="fill"/>
</android.support.design.widget.AppBarLayout>
<!--THIS VIEW WILL BE PINNED-->
<android.support.v4.view.ViewPager
android:id="@+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="10dp"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
android:scrollbars="vertical"
android:clipToPadding="false"
android:requiresFadingEdge="vertical"
android:fadingEdgeLength="10dp"/>
<!-- FLOATING ACTION BUTTON -->
<android.support.design.widget.FloatingActionButton
android:id="@+id/newBetFab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginRight="20dp"
android:layout_marginBottom="40dp"
android:layout_gravity="bottom|end"
android:src="@drawable/icon_add"
app:fabSize="mini"
app:backgroundTint="@color/accent"
app:rippleColor="@color/primary"
app:pressedTranslationZ="10dp"
app:elevation="15dp"
app:borderWidth="0dp"/>
</android.support.v4.view.ViewPager>
</android.support.design.widget.CoordinatorLayout>
TabsPagerAdapter.cs：
using System;
using Android.App;
using Android.OS;
using Android.Support.Design.Widget;
using Android.Support.V7.Widget;
using Android.Views;
using Android.Widget;
using SupportFragment = Android.Support.V4.App.Fragment;
using System.Collections.Generic;
using Refractored.Controls;
using App.Adapters;
using static App.MainActivity;
using IN.Galaxyofandroid.Spinerdialog;
using Android.Support.V4.View;
/// <summary>
/// This screen shows a view of the last conversations made by the user
/// </summary>
namespace App.Fragments
{
public class HomeFragment : SupportFragment, IRecyclerAdapterCallback, IOnSpinerItemClick
{
private CircleImageView circleImage;
private FloatingActionButton mFAB;
private CoordinatorLayout mCoordLayout;
private RecyclerView mRecyclerView;
private RecyclerView.LayoutManager mLayoutManager;
private RecyclerView.Adapter mAdapter;
public static List<Bet> mBets { get; private set; }
private TabLayout mTabLayout;
private CircleImageView mCircleProfileImage;
private FloatingActionButton mNewBetFAB;
private SpinnerDialog mSpinnerDialog;
private List<string> spinnerItems;
private View view;
public override void OnCreate(Bundle savedInstanceState)
{
HasOptionsMenu = true;
base.OnCreate(savedInstanceState);
// Create your fragment here
}
public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
// Use this to return your custom view for this Fragment
view = inflater.Inflate(Resource.Layout.Home, container, false);
TextView toolbarTitle = view.FindViewById<TextView>(Resource.Id.toolbar_title);
toolbarTitle.Text = Application.Context.GetString(Resource.String.ApplicationName);
// **************************************************************
//TABS
mTabLayout = view.FindViewById<TabLayout>(Resource.Id.tabLayout);
mTabLayout.AddTab(mTabLayout.NewTab().SetText("Chats"));
mTabLayout.AddTab(mTabLayout.NewTab().SetText("Bets"));
mTabLayout.AddTab(mTabLayout.NewTab().SetText("Ka-ching"));
mRecyclerView = view.FindViewById<RecyclerView>(Resource.Id.recyclerView);
//Create our layout manager
mLayoutManager = new LinearLayoutManager(Application.Context);
mRecyclerView.SetLayoutManager(mLayoutManager);
mBets = new List<Bet>();
mBets.Add(new Bet() { BetName = "Tom Hanks", Message = "Jeg tror jeg vinner", Date = "25.01.17" });
mBets.Add(new Bet() { BetName = "Ellen DeGeneres", Message = "Jeg tror jeg vinner", Date = "04.03.17" });
mBets.Add(new Bet() { BetName = "Barack Hussain Obama", Message = "Wanna guess who won?", Date = "04.03.17", ProfilePicture = Resource.Drawable.obama });
mBets.Add(new Bet() { BetName = "Tom Hanks", Message = "Run, forest. Run!", Date = "25.01.17", ProfilePicture = Resource.Drawable.profile });
mBets.Add(new Bet() { BetName = "Ellen DeGeneres", Message = "Be kind with one another", Date = "04.03.17", ProfilePicture = Resource.Drawable.profile });
mBets.Add(new Bet() { BetName = "President Obama", Message = "Yes, we can!", Date = "25.01.17", ProfilePicture = Resource.Drawable.obama});
mBets.Add(new Bet() { BetName = "Bernie Sanders", Message = "I'm a progressive", Date = "04.03.17", ProfilePicture = Resource.Drawable.bernie });
mAdapter = new RecyclerAdapter(mBets, mRecyclerView, this);
mRecyclerView.SetAdapter(mAdapter);
mCircleProfileImage = view.FindViewById<CircleImageView>(Resource.Id.circleProfileImage);
mCircleProfileImage.Click += (o, e) =>
{
//mCircleProfileImage.BorderColor = Resource.Color.lightgray;
Console.WriteLine("Go to settings..");
ReplaceFragment(new SettingsFragment(), null);
};
//**************************************
// Searchable spinner (list of users)
InitSpinnerItems(mBets);
//***************************************
// FAB - Create a new bet
mNewBetFAB = view.FindViewById<FloatingActionButton>(Resource.Id.newBetFab);
mNewBetFAB.Click += delegate
{
mSpinnerDialog = new SpinnerDialog(Activity, spinnerItems, "Choose friend");
mSpinnerDialog.BindOnSpinerListener(this);
mSpinnerDialog.ShowSpinerDialog();
};
//Viewpager
ViewPager viewPager = view.FindViewById<ViewPager>(Resource.Id.viewpager);
PagerAdapter pagerAdapter = new TabsPagerAdapter(Activity.SupportFragmentManager);
viewPager.Adapter = pagerAdapter;
mTabLayout.SetupWithViewPager(viewPager);
return view;
}
/// <summary>
/// Callback function that is called when user has pressed on one of the conversations in the RecyclerAdapter
/// </summary>
/// <param name="position"></param>
public void OnMethodCallback(int position)
{
ReplaceFragment(new ChatFragment(), null);
}
public override void OnCreateOptionsMenu(IMenu menu, MenuInflater inflater)
{
//Activity.MenuInflater.Inflate(Resource.Menu.overflow_menu, menu);
//Activity.OnCreateOptionsMenu(menu);
inflater.Inflate(Resource.Menu.overflow_menu, menu);
base.OnCreateOptionsMenu(menu, inflater);
}
public override bool OnOptionsItemSelected(IMenuItem item)
{
switch (item.ItemId)
{
case Resource.Id.action_add:
//mBets.Add(new Bet() { BetName = "Steinar Ragnarok", Message = "Jeg tror jeg vinner", Date = "30.06.17" });
//mAdapter.NotifyItemInserted(0); //notify adapter that item was inserted at the head (pos 0)
ReplaceFragment(new ChatFragment(), null);
return true;
case Resource.Id.action_search:
//Toast.MakeText(Application.Context, "You clicked on search", ToastLength.Short).Show();
return false;
case Resource.Id.action_settings:
//Toast.MakeText(Application.Context, "You clicked on search", ToastLength.Short).Show();
return false;
}
return base.OnOptionsItemSelected(item);
}
// Replace fragment
private void ReplaceFragment(SupportFragment fragment, Bundle bundle)
{
if (Globals.mCurrentFragment.Equals(fragment))
{
Toast.MakeText(Application.Context, "You're already in that menu.", ToastLength.Short).Show();
return;
}
var trans = FragmentManager.BeginTransaction();
//set animation (including animation for 'back' button)
trans.SetCustomAnimations(Resource.Animation.abc_grow_fade_in_from_bottom, Resource.Animation.abc_shrink_fade_out_from_bottom, Resource.Animation.abc_grow_fade_in_from_bottom, Resource.Animation.abc_shrink_fade_out_from_bottom);
if (bundle != null)
fragment.Arguments = bundle;
trans.Replace(Resource.Id.fragmentContainer, fragment); // hide the current fragment
trans.AddToBackStack(null); // makes it possible to go back to the current fragment late
trans.Commit();
Globals.mStackFragment.Push(Globals.mCurrentFragment); // put fragment in back-stack before switching
Globals.mCurrentFragment = fragment; // update current fragment
}
private void InitSpinnerItems(List<Bet> betsList)
{
spinnerItems = new List<string>();
foreach (Bet bet in betsList ){
spinnerItems.Add(bet.BetName);
}
}
/// <summary>
/// What to do when SearchableSpinner is opened
/// </summary>
/// <param name="p0"></param>
/// <param name="p1"></param>
public void OnClick(string item, int position)
{
Bundle bundle = new Bundle();
bundle.PutInt("spinner_chosen_position", position);
ReplaceFragment(new CreateBetFragment(), bundle);
Toast.MakeText(Activity, $"Nr {position}, {item}, was chosen.", ToastLength.Short).Show();
}
}
}