AndroidStudio Question) View Pager does not display Fragments on the screen.

viewpager and using tablayout toolbar swipe activity in the process of implementing a problem. Not the contents on the screen the fragment viewpager. Some worry, and I hope you will tell you you know what went wrong, please.

_) _?.

Below is MyViewPagerAdapter.java.

package com.zer0kencreation.macaronpicker;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;

public class MyViewPagerAdapter extends FragmentStatePagerAdapter {
    public MyViewPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        switch (position){
            case 0:
                return new OthersFragment();
            case 1:
                return new MineFragment();
            case 2:
                return new ReceiverFragment();
            case 3:
                return new GiverFragment();
        }
        return null;
    }

    @Override
    public int getCount() {
        return 4;
    }
}

Below is Main Activity.It's java.

package com.zer0kencreation.macaronpicker;

import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;

public class MainActivity extends AppCompatActivity {

    private Toolbar mainTB;
    private TabLayout mainTL;
    private ViewPager mainVP;
    private MyViewPagerAdapter vpAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mainTB = (Toolbar)findViewById(R.id.main_tb);
        setSupportActionBar(mainTB);
        mainTL = (TabLayout)findViewById(R.id.main_tl);

        mainVP = (ViewPager)findViewById(R.id.main_vp);
        vpAdapter = new MyViewPagerAdapter(getSupportFragmentManager());
        mainVP.setAdapter(vpAdapter);
        mainVP.setCurrentItem(0);

        mainTL.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                switch (tab.getPosition()){
                    case 0:
                        mainVP.setCurrentItem(0);
                        break;
                    case 1:
                        mainVP.setCurrentItem(1);
                        break;
                    case 2:
                        mainVP.setCurrentItem(2);
                        break;
                    case 3:
                        mainVP.setCurrentItem(3);
                        break;
                }
            }

            @Override
            public void onTabUnselected(TabLayout.Tab tab) {

            }

            @Override
            public void onTabReselected(TabLayout.Tab tab) {

            }
        });

    }
}

Below is the class of each fragment.

[OhterFragment.java]

package com.zer0kencreation.macaronpicker;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class OthersFragment extends android.support.v4.app.Fragment {

    public OthersFragment(){

    }

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_others, container, false);
    }
}

[MineFragment.java]

package com.zer0kencreation.macaronpicker;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class MineFragment extends android.support.v4.app.Fragment {

    public MineFragment(){

    }

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_mine, container, false);
    }
}

[ReceiverFragment.java]

package com.zer0kencreation.macaronpicker;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class ReceiverFragment extends android.support.v4.app.Fragment {

    public ReceiverFragment(){

    }

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_receiver, container, false);
    }
}

[GiverFragment.java]

package com.zer0kencreation.macaronpicker;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class GiverFragment extends android.support.v4.app.Fragment {

    public GiverFragment(){

    }

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_giver, container, false);
    }
}

Below is activity_main.xml.

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/main_abl"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <android.support.v7.widget.Toolbar
            android:id="@+id/main_tb"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:layout_scrollFlags="scroll|enterAlways"></android.support.v7.widget.Toolbar>

        <android.support.design.widget.TabLayout
            android:id="@+id/main_tl"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <android.support.design.widget.TabItem
                android:id="@+id/others"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/tab1" />

            <android.support.design.widget.TabItem
                android:id="@+id/mine"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/tab2" />

            <android.support.design.widget.TabItem
                android:id="@+id/receiver"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/tab3" />

            <android.support.design.widget.TabItem
                android:id="@+id/giver"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/tab4" />
        </android.support.design.widget.TabLayout>
    </android.support.design.widget.AppBarLayout>

    <android.support.v4.widget.NestedScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="android.support.design.widget.AppBarLayout$ScrollingViewBehavior">

        <android.support.v4.view.ViewPager
            android:id="@+id/main_vp"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />
    </android.support.v4.widget.NestedScrollView>
</android.support.design.widget.CoordinatorLayout>

Below is the layout of each fragment.

[fragment_others.xml]

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:text="others fragment"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</LinearLayout>

[fragment_others.xml]

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:text="mine fragment"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</LinearLayout>

[fragment_receiver.xml]

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:text="receiver fragment"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</LinearLayout>

[fragment_giver.xml]

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:text="giver fragment"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</LinearLayout>

android android-viewpager

2022-09-22 16:44

1 Answers

Didn't you set up a viewPager on tabLayout?

mainTL. setupWithViewPager(mainVP)

2022-09-22 16:44

If you have any answers or tips

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