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how to make android app in java using navigation drawer and viewpager/viewpager2

hello I am making an application to debate in android studio using Java, I intend that the application occupies a navigation drawer and a viewpager / viewpager2. I am very new programming in androidstudio and therefore I have followed several video tutorials to incorporate viewpager / viepager 2 with navigation drawer but so far none works for me (the navigation drawer only works for me), the last thing I tried was to use viewpager (since with viepager 2 I had problems calling the adapter from the main), but when compiling the project the emulator was I was left with a black screen and it did not show anything. I hope you can help me because this project is very important to me. Here is part of my code:
main:
import androidx.annotation.NonNull;
import androidx.appcompat.app.ActionBarDrawerToggle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.core.view.GravityCompat;
import androidx.drawerlayout.widget.DrawerLayout;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentPagerAdapter;
import androidx.fragment.app.FragmentTransaction;
import androidx.viewpager.widget.PagerAdapter;
import androidx.viewpager.widget.ViewPager;
import androidx.viewpager2.adapter.FragmentStateAdapter;
import androidx.viewpager2.widget.ViewPager2;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.MenuItem;
import android.widget.Toast;
import com.google.android.gms.auth.api.signin.GoogleSignIn;
import com.google.android.gms.auth.api.signin.GoogleSignInAccount;
import com.google.android.material.appbar.AppBarLayout;
import com.google.android.material.navigation.NavigationView;
import com.google.android.material.tabs.TabItem;
import com.google.android.material.tabs.TabLayout;
import com.google.android.material.tabs.TabLayoutMediator;
import Fragments.generaDebate;
import Fragments.perfil_user;
public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
DrawerLayout drawerLayout;
ActionBarDrawerToggle actionBarDrawerToggle;
Toolbar toolbar;
NavigationView navigationView;
//variables para cargar el fragment
FragmentManager fragmentManager;
FragmentTransaction fragmentTransaction;
String personName;
//variable viewpager
ViewPager pager;
TabLayout tablayout;
TabItem first_item,second_item;
pageAdapter adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar=findViewById(R.id.toolbar);
setSupportActionBar(toolbar);//se pasa el toolbar
drawerLayout=findViewById(R.id.drawer);
navigationView=findViewById(R.id.navigationView);
navigationView.setNavigationItemSelectedListener(this);
actionBarDrawerToggle=new ActionBarDrawerToggle(this,drawerLayout,toolbar,R.string.open,R.string.close);
drawerLayout.addDrawerListener(actionBarDrawerToggle);
actionBarDrawerToggle.setDrawerIndicatorEnabled(true);
actionBarDrawerToggle.syncState();
//carga viewpager
pager=findViewById(R.id.view);
tablayout=findViewById(R.id.title_menu);
first_item=findViewById(R.id.first_item);
second_item=findViewById(R.id.second_item);
//declarando adapter en el main
FragmentManager fragmentManager;
fragmentManager=getSupportFragmentManager();
adapter=new pageAdapter(fragmentManager, FragmentPagerAdapter.BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT,tablayout.getTabCount());
pager.setAdapter(adapter);
tablayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
pager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
pager.addOnAdapterChangeListener((ViewPager.OnAdapterChangeListener) new TabLayout.TabLayoutOnPageChangeListener(tablayout));
//cargar fragment principal
FragmentTransaction fragmentTransaction;
fragmentTransaction=fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.container, new perfil_user());
fragmentTransaction.commit();
}
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
if (item.getItemId() == R.id.user){
FragmentManager fragmentManager;
FragmentTransaction fragmentTransaction;
fragmentManager=getSupportFragmentManager();
fragmentTransaction=fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.container, new perfil_user());
fragmentTransaction.commit();
}
else if (item.getItemId() == R.id.exit){
//finish();
loggin login=new loggin();
login.signOut();
}
//aquí van las otros fragment
drawerLayout.closeDrawer(GravityCompat.START);
return false;
}
}
adapter:
import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentPagerAdapter;
import androidx.lifecycle.Lifecycle;
import androidx.viewpager2.adapter.FragmentStateAdapter;
import java.util.ArrayList;
import Fragments.generaDebate;
import Fragments.perfil_user;
public class pageAdapter extends FragmentPagerAdapter {
private int tabsNumber;
public pageAdapter(#NonNull FragmentManager fm, int behavior,int tabs) {
super(fm, behavior);
}
#NonNull
#Override
public Fragment getItem(int position) {
switch (position){
case 1:
return new perfil_user ();
case 2:
return new generaDebate();
default:
return null;
}
}
#Override
public int getCount() {
return tabsNumber;
}
}

The navigation drawer is the most common feature offered by android and the navigation drawer is a UI panel that shows your app’s main navigation menu. It is also one of the important UI elements, which provides actions preferable to the users like example changing user profile, changing settings of the application, etc. In this article, it has been discussed step by step to implement the navigation drawer in android
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout
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:background="#color/bgColor"
android:layout_height="match_parent"
tools:context=".activities.MainActivity">
<com.google.android.material.appbar.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:elevation="0dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:gravity="center_vertical"
android:background="#color/bgColor"
android:paddingStart="20dp"
android:paddingEnd="20dp"
android:orientation="horizontal">
</LinearLayout>
</com.google.android.material.appbar.AppBarLayout>
<androidx.viewpager2.widget.ViewPager2
android:id="#+id/vp_horizontal_ntb"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/navigation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:background="?android:attr/windowBackground"
android:foreground="?attr/selectableItemBackground"
app:menu="#menu/bottom_navigation"
app:elevation="10dp"
app:labelVisibilityMode="labeled"
app:itemIconTint="#color/bottom_navigation_color"
app:itemTextColor="#color/bottom_navigation_color"
app:itemBackground="#color/bottomNavigationBackground"/>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
menu.xml
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:id="#+id/navigationMenu"
android:icon="#android:drawable/ic_menu_sort_by_size"
android:title="Menu" />
<item
android:id="#+id/navigationMyCourses"
android:icon="#drawable/ic_email"
android:title="Courses" />
<item
android:id="#+id/navigationHome"
android:icon="#drawable/ic_home"
android:title="Home" />
<item
android:id="#+id/m_refer"
android:icon="#android:drawable/ic_menu_share"
android:title="Refer" />
<item
android:id="#+id/navigationMyProfile"
android:icon="#drawable/ic_back"
android:title="User" />
</menu>
ViewPagerAdapter.java
public class ViewPagerAdapter extends FragmentStateAdapter {
public ViewPagerAdapter(#NonNull #NotNull FragmentActivity fragmentActivity) {
super(fragmentActivity);
}
#NonNull
#NotNull
#Override
public Fragment createFragment(int p) {
switch (p) {
case 0:
return new ProfileFragment();
case 1:
return new LeaderBoardFragment();
case 2:
return new HomeFragment();
case 3:
return new ReferFragment();
case 4:
return new ProfileFragment();
default:
return new HomeFragment();
}
}
#Override
public int getItemCount() {
return 5;
}
}
MainActivity.java
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
}
private void initView() {
this.viewPager2 = findViewById(R.id.vp_horizontal_ntb);
viewPager2.setOffscreenPageLimit(100);
this.bottomNavigationView = findViewById(R.id.navigation);
adapter = new ViewPagerAdapter(this);
viewPager2.setAdapter(adapter);
viewPager2.registerOnPageChangeCallback(new ViewPager2.OnPageChangeCallback() {
#Override
public void onPageSelected(int position) {
super.onPageSelected(position);
switch (position) {
case 0:
bottomNavigationView.getMenu().findItem(R.id.navigationMenu).setChecked(true);
break;
case 1:
bottomNavigationView.getMenu().findItem(R.id.navigationMyCourses).setChecked(true);
break;
case 2:
bottomNavigationView.getMenu().findItem(R.id.navigationHome).setChecked(true);
break;
case 3:
bottomNavigationView.getMenu().findItem(R.id.m_refer).setChecked(true);
break;
case 4:
bottomNavigationView.getMenu().findItem(R.id.navigationMyProfile).setChecked(true);
break;
}
}
});
bottomNavigationView.setOnItemSelectedListener(new NavigationBarView.OnItemSelectedListener() {
#SuppressLint("NonConstantResourceId")
#Override
public boolean onNavigationItemSelected(#NonNull #NotNull MenuItem item) {
switch (item.getItemId()) {
case R.id.navigationHome:
viewPager2.setCurrentItem(2);
break;
case R.id.navigationMyProfile:
viewPager2.setCurrentItem(4);
break;
case R.id.m_refer:
viewPager2.setCurrentItem(3);
break;
case R.id.navigationMyCourses:
viewPager2.setCurrentItem(1);
break;
case R.id.navigationMenu:
viewPager2.setCurrentItem(0);
break;
}
return false;
}
});
CoordinatorLayout.LayoutParams layoutParams = (CoordinatorLayout.LayoutParams) bottomNavigationView.getLayoutParams();
layoutParams.setBehavior(new BottomNavigationBehavior());
bottomNavigationView.setSelectedItemId(R.id.navigationMenu);
}
}
Happy Coding

java.lang.IllegalArgumentException: No view found for id 0x7f0d00c4

I want to pass some List from fragment into 2 other fragment. When i pass data to fragment two it is going well. But it is error when pass to the fragment three
Error code
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.yehezkiel.eclassapp, PID: 15267
java.lang.IllegalArgumentException: No view found for id 0x7f0d00c4 (com.example.yehezkiel.eclassapp:id/fragment3) for
fragment ThreeFragment{e045027 #3 id=0x7f0d00c4}
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1415)
at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1752)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1821)
at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:797)
at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2595)
at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2382)
at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2337)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2244)
at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:702)
at android.os.Handler.handleCallback(Handler.java:742)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:157)
at android.app.ActivityThread.main(ActivityThread.java:5555)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:745)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:635)
Pass Code in OneFragment.java
Bundle bundle=new Bundle();
bundle.putStringArrayList("keys", keys);
//set Fragmentclass Arguments
Fragment fragobj=new TwoFragment();
fragobj.setArguments(bundle);
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.frag2, fragobj).commitAllowingStateLoss();
Bundle bundle2=new Bundle();
bundle2.putStringArrayList("keys", keys);
//set Fragmentclass Arguments
Fragment fragobj2=new ThreeFragment();
fragobj2.setArguments(bundle2);
FragmentManager fragmentManager2 = getFragmentManager();
fragmentManager2.beginTransaction().replace(R.id.fragment3, fragobj2).commitAllowingStateLoss();
the first pass into TwoFragment did well. But the second pass gave me error like that. Please help me. I have been check all of the id in the ThreeFragment.xml and all correct.
ThreeFragment.java
package com.example.yehezkiel.eclassapp;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import java.util.ArrayList;
import java.util.List;
public class ThreeFragment extends Fragment {
View v;
private List<DaftarPengumuman> listPengumuman = new ArrayList<>();
private ArrayList<String> obj3 = new ArrayList<>();
public ThreeFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
v = inflater.inflate(R.layout.fragment_three, container, false);
Bundle bundle = this.getArguments();
if(getArguments()!=null)
{
obj3 = bundle.getStringArrayList("keys");
Log.e("nba",obj3.toString());
}
// Inflate the layout for this fragment
return v;
}
}
fragment_three.xml
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/fragment3"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.yehezkiel.eclassapp.ThreeFragment">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Three"
android:textSize="40dp"
android:textStyle="bold"
android:layout_centerInParent="true"/>
</FrameLayout>
This is my MainActivity.java that is stored the viewpager
package com.example.yehezkiel.eclassapp;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.design.widget.NavigationView;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private Toolbar toolbar;
private TabLayout tabLayout;
private ViewPager viewPager;
private List<MataKuliah> listMatkul = new ArrayList<>();
private ArrayList<String> keys = new ArrayList<>();
private myAdapter myAdapter;
private Button logoutBtn;
private FirebaseAuth mAuth;
private FirebaseAuth.AuthStateListener authListener;
private RecyclerView mRecycleView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
private DrawerLayout mDrawerLayout;
private ActionBarDrawerToggle mToggle;
private Toolbar mToolbar;
private NavigationView mNavigationView;
private TextView mTextName;
private TextView mTextNim;
private ProgressBar mProgressBar;
static {
FirebaseDatabase.getInstance().setPersistenceEnabled(true);
}
DatabaseReference userRef = FirebaseDatabase.getInstance().getReference("users");
FirebaseUser users = FirebaseAuth.getInstance().getCurrentUser();
DatabaseReference mataKuliahRef = FirebaseDatabase.getInstance().getReference("courses");
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
mAuth = FirebaseAuth.getInstance();
//Navbar menu
mToolbar = (Toolbar) findViewById(R.id.navbaraction);
setSupportActionBar(mToolbar);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawabel_main);
mToggle = new ActionBarDrawerToggle(this, mDrawerLayout, R.string.open, R.string.close);
mDrawerLayout.addDrawerListener(mToggle);
mToggle.syncState();
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
mNavigationView = (NavigationView) findViewById(R.id.nav_menu);
View header = mNavigationView.getHeaderView(0);
mTextName = (TextView) header.findViewById(R.id.header_name);
mTextNim = (TextView) header.findViewById(R.id.header_nim);
mProgressBar = (ProgressBar) findViewById(R.id.progressBar2);
mProgressBar.setVisibility(View.VISIBLE);
//Tab Layout
viewPager = (ViewPager) findViewById(R.id.viewpager);
setupViewPager(viewPager);
tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
mNavigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case (R.id.tugas):
break;
case (R.id.logout_menu):
signOut();
break;
}
return true;
}
});
userRef.child(users.getUid()).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String name = (String) dataSnapshot.child("name").getValue().toString();
String nim = (String) dataSnapshot.child("nim").getValue().toString();
mTextNim.setText(nim);
mTextName.setText(name);
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
authListener = new FirebaseAuth.AuthStateListener() {
#Override
public void onAuthStateChanged(#NonNull FirebaseAuth firebaseAuth) {
FirebaseUser user = firebaseAuth.getCurrentUser();
if (user == null) {
startActivity(new Intent(MainActivity.this, LoginActivity.class));
finish();
}
}
};
}
private void setupViewPager(ViewPager viewPager) {
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
adapter.addFragment(new OneFragment(), "Beranda");
adapter.addFragment(new TwoFragment(), "Tugas");
adapter.addFragment(new ThreeFragment(), "Pengumuman");
viewPager.setAdapter(adapter);
}
class ViewPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public ViewPagerAdapter(FragmentManager manager) {
super(manager);
}
#Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
#Override
public int getCount() {
return mFragmentList.size();
}
public void addFragment(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
#Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if(mToggle.onOptionsItemSelected(item)){
return true;
}
return super.onOptionsItemSelected(item);
}
private void signOut() {
mAuth.signOut();
}
#Override
public void onStart() {
super.onStart();
mAuth.addAuthStateListener(authListener);
}
}
MainActivity.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout 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:id="#+id/drawabel_main"
tools:context="com.example.yehezkiel.eclassapp.MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<include
layout="#layout/navbar_action"
android:layout_width="match_parent"
android:layout_height="wrap_content"></include>
<android.support.design.widget.TabLayout
android:id="#+id/tabs"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:tabGravity="fill"
app:tabMode="fixed" />
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
<ProgressBar
android:id="#+id/progressBar2"
style="?android:attr/progressBarStyle"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="center_horizontal"
android:visibility="visible"
tools:layout_editor_absoluteX="0dp"
tools:layout_editor_absoluteY="304dp" />
<android.support.v7.widget.RecyclerView
android:id="#+id/MainRView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="2dp"
android:layout_marginEnd="6dp"
android:layout_marginStart="6dp"
android:layout_marginTop="2dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
</android.support.v7.widget.RecyclerView>
<Button
android:id="#+id/logoutBtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="444dp"
android:background="#color/colorPrimary"
android:text="LOGOUT"
android:textColor="#color/white"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.945"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</LinearLayout>
<android.support.design.widget.NavigationView
android:layout_width="wrap_content"
android:layout_height="match_parent"
app:menu="#menu/navbar_main"
android:layout_gravity="start"
app:headerLayout="#layout/navbar_header"
android:id="#+id/nav_menu">
</android.support.design.widget.NavigationView>
</android.support.v4.widget.DrawerLayout>

application crashes when I move from one fragment to another

I have four fragments in my application. the first one gets GPS data for calculating speed which works fine. as soon as the application gets the gps data and move to other fragments it crashes. FYI, other fragments are all without any code.
here is my MainActivity class:
package ir.helpx.speedx;
import android.Manifest;
import android.content.pm.ActivityInfo;
import android.content.pm.PackageManager;
import android.os.Build;
import android.support.design.widget.TabLayout;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.view.WindowManager;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
Toolbar toolbar;
TabLayout tabLayout;
ViewPager viewPager;
ViewPagerAdapter viewPagerAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar =(Toolbar)findViewById(R.id.toolBar);
setSupportActionBar(toolbar);
tabLayout = (TabLayout) findViewById(R.id.tabLayout);
viewPager = (ViewPager) findViewById(R.id.viewPager);
viewPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager());
viewPagerAdapter.addFragments(new HomeFragment(), "Home");
viewPagerAdapter.addFragments(new CompassFragment(), "Compass");
viewPagerAdapter.addFragments(new HUDFragment(), "HUD");
viewPager.setAdapter(viewPagerAdapter);
tabLayout.setupWithViewPager(viewPager);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
setRequestedOrientation (ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION}, 1);
}
}
#Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
switch (requestCode) {
case 1:
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(this,"GPS permission granted", Toast.LENGTH_LONG).show();
// get Location from your device by some method or code
} else {
// show user that permission was denied. inactive the location based feature or force user to close the app
}
break;
}
}
}
and my MainActivity XML:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
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"
tools:context="ir.helpx.speedx.MainActivity">
<android.support.design.widget.AppBarLayout
android:layout_height="wrap_content"
android:layout_width="368dp"
tools:layout_editor_absoluteY="0dp"
tools:layout_editor_absoluteX="8dp"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<include
android:layout_height="wrap_content"
android:layout_width="match_parent"
layout="#layout/toolbar_layout"
/>
<android.support.design.widget.TabLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/tabLayout"
app:tabMode="fixed"
app:tabGravity="fill"
></android.support.design.widget.TabLayout>
<android.support.v4.view.ViewPager
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/viewPager"
></android.support.v4.view.ViewPager>
</android.support.design.widget.AppBarLayout>
</android.support.constraint.ConstraintLayout>
and here is my first Fragment called Home:
package ir.helpx.speedx;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;
/**
* A simple {#link Fragment} subclass.
*/
public class HomeFragment extends Fragment implements LocationListener{
public HomeFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
LocationManager mgr;
mgr = (LocationManager)getContext().getSystemService(getActivity().LOCATION_SERVICE);
mgr.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
this.onLocationChanged(null);
return inflater.inflate(R.layout.fragment_home, container, false);
}
//TextView msg1;
#Override
public void onLocationChanged(Location location) {
if (location==null){
TextView currentSpeed = null;
}
else {
float nCurrentSpeed = location.getSpeed();
TextView currentSpeed = (TextView) getView().findViewById(R.id.speed);
currentSpeed.setText((int)nCurrentSpeed*18/5+"");
//msg1=currentSpeed;
Toast.makeText(getActivity(), "Location Found!", Toast.LENGTH_LONG).show();
}
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onProviderDisabled(String provider) {
}
}
and here is the related XML
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="ir.helpx.speedx.HomeFragment">
<!-- TODO: Update blank fragment layout -->
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="#string/speed"
android:gravity="center"
android:textSize="180sp"
android:textStyle="bold"
android:textColor="#android:color/white"
android:id="#+id/speed"/>
</FrameLayout>
and here is my second Fragment:
package ir.helpx.speedx;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
/**
* A simple {#link Fragment} subclass.
*/
public class HUDFragment extends Fragment {
public HUDFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_hud, container, false);
}
}
rest of the fragments are similar to
I have a toolbar XML:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="wrap_content"
android:background="?attr/colorPrimary"
android:minWidth="?attr/actionBarSize"
android:fitsSystemWindows="true"
android:id="#+id/toolBar"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
>
</android.support.v7.widget.Toolbar>
and finally my my ViewPagerAdapter:
package ir.helpx.speedx;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import java.util.ArrayList;
/**
* Created by abe on 5/29/2017.
*/
public class ViewPagerAdapter extends FragmentPagerAdapter {
ArrayList<Fragment> fragments = new ArrayList<>();
ArrayList<String> tabTitles = new ArrayList<>();
public void addFragments(Fragment fragments, String titles){
this.fragments.add(fragments);
this.tabTitles.add(titles);
}
public ViewPagerAdapter(FragmentManager fm){
super(fm);
}
#Override
public Fragment getItem(int position) {
return fragments.get(position);
}
#Override
public int getCount() {
return fragments.size();
}
#Override
public CharSequence getPageTitle(int position) {
return tabTitles.get(position);
}
}
Please HELP me! thank you

I think I could fix it by adding
viewPager.setOffscreenPageLimit(4);
to my MainActivity. I think that was because by default ViewPager retains only one page in the view hierarchy in an idle state. Please tell me if I did the right thing!

cannot resolve symbol 'toolbar' r.id.toolbar [closed]

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i'm trying to create a sliding drawer. I spent forever getting my imports to match my code, in terms of getSupportActionBar vs getActionBar etc., I suspect the issue is somewhere in the activity_main.xml but I'm at a loss for what to put there.
MainActivity.java
package me.paxana.alerta;
import android.app.Activity;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.app.FragmentManager;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarDrawerToggle;
import android.app.Fragment;
import android.content.Intent;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MenuInflater;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.Toolbar;
import com.parse.ParseUser;
import java.util.ArrayList;
import java.util.List;
import butterknife.Bind;
import butterknife.ButterKnife;
import me.paxana.alerta.adapter.SlidingMenuAdapter;
import me.paxana.alerta.fragment.Fragment1;
import me.paxana.alerta.fragment.Fragment2;
import me.paxana.alerta.fragment.Fragment3;
import me.paxana.alerta.model.ItemSlideMenu;
public class MainActivity extends AppCompatActivity {
public static final String TAG = MainActivity.class.getSimpleName();
private List<ItemSlideMenu> listSliding;
private SlidingMenuAdapter adapter;
private ListView listViewSliding;
private DrawerLayout drawerLayout;
private android.support.v7.app.ActionBarDrawerToggle actionBarDrawerToggle;
private Toolbar mToolbar;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ButterKnife.bind(this);
ParseUser currentUser = ParseUser.getCurrentUser();
if (currentUser == null) {
navigateToLogin();
}
else {
Log.i(TAG, currentUser.getUsername());
}
listViewSliding = (ListView)findViewById(R.id.lv_sliding_menu);
drawerLayout = (DrawerLayout)findViewById(R.id.drawer_layout);
listSliding = new ArrayList<>();
//add item for sliding list
listSliding. add(new ItemSlideMenu(R.drawable.ic_action_settings, "Settings"));
listSliding.add(new ItemSlideMenu(R.drawable.ic_action_about, "About"));
listSliding.add(new ItemSlideMenu(R.mipmap.ic_launcher, "Android"));
adapter = new SlidingMenuAdapter(this, listSliding);
listViewSliding.setAdapter(adapter);
//display icon to open/close slider
mToolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(mToolbar);
assert getActionBar() != null;
getActionBar().setDisplayHomeAsUpEnabled(true);
//set title
setTitle(listSliding.get(0).getTitle());
//item selected
listViewSliding.setItemChecked(0, true);
//close menu
drawerLayout.closeDrawer(listViewSliding);
//handle on item click
listViewSliding.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
//set title
setTitle(listSliding.get(position).getTitle());
//item selected
listViewSliding.setItemChecked(position, true);
//close menu
drawerLayout.closeDrawer(listViewSliding);
}
});
actionBarDrawerToggle = new ActionBarDrawerToggle(this, drawerLayout, R.string.drawer_opened, R.string.drawer_closed) {
#Override
public void onDrawerOpened(View drawerView) {
super.onDrawerOpened(drawerView);
invalidateOptionsMenu();
}
#Override
public void onDrawerClosed(View drawerView) {
super.onDrawerClosed(drawerView);
invalidateOptionsMenu();
}
};
drawerLayout.setDrawerListener(actionBarDrawerToggle);
}
private void navigateToLogin() {
Intent intent = new Intent(this, LoginActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if(actionBarDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
int itemId = item.getItemId();
if (itemId == R.id.action_logout) {
ParseUser.logOut();
navigateToLogin();
}
return super.onOptionsItemSelected(item);
}
#Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
actionBarDrawerToggle.syncState();
}
//create method replace fragment
private void replaceFragment(int pos) {
android.support.v4.app.Fragment fragment = null;
switch (pos) {
case 0:
fragment = new Fragment1();
break;
case 1:
fragment = new Fragment2();
break;
case 2:
fragment = new Fragment3();
break;
default:
fragment = new Fragment1();
break;
}
if(null != fragment) {
android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
android.support.v4.app.FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.replace(R.id.main_content, fragment);
transaction.addToBackStack(null);
transaction.commit();
}
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/drawer_layout"
tools:context="me.paxana.alerta.MainActivity">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/main_content">
</RelativeLayout>
<ListView
android:layout_width="200dp"
android:layout_height="match_parent"
android:id="#+id/lv_sliding_menu"
android:background="#FFFFFF"
android:choiceMode="singleChoice"
android:layout_gravity="start" />
</android.support.v7.widget.Toolbar>

Why are you using android.support.v7.widget.Toolbar for your main_layout root tag? That's not what android says.
You should use that Toolbar just for using Toolbar with your activity.
See: setContentView(R.layout.activity_main);
That won't work at all.
Use it like this:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:id="#+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="me.paxana.alerta.MainActivity">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="#color/ColorPrimary"
app:layout_collapseMode="pin"
app:layout_scrollFlags="scroll|enterAlways"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"
app:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar" />
<ListView
android:id="#+id/lv_sliding_menu"
android:layout_width="200dp"
android:layout_height="match_parent"
android:layout_gravity="start"
android:background="#FFFFFF"
android:choiceMode="singleChoice" />
</RelativeLayout>
I'd rather to use CoordinatorLayout with AppCompat or this Toolbar implementation too.
Also,
//display icon to open/close slider
mToolbar = (Toolbar) findViewById(R.id.toolbar);
Here you were using toolbar as that Toolbar id.
Use it like this in your xml:
android:id="#+id/toolbar"
Above code should work now.Also, you've many not used in your imports like:
import android.support.v7.app.ActionBarActivity;
and etc.
Read the docs please.

Use this
R.id.drawer_layout
Instead of
R.id.toolbar

Why does this Navigation Drawer not open?

I'm trying to make a Navigation Drawer, I'm reading a lot of guides on how to do this and I think it should work now, but the Drawer does not open when I click on the title (when I manually try to open it, then the icon will get smaller, but still no menu appears). Also, I'm not getting any errors or exception, so I think I might be missing something which I cannot figure out myself.
This is the code of my BaseActivity (the drawer activity which gets extended by my MainActivity):
import android.os.Bundle;
import android.app.Activity;
import android.content.res.Configuration;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.widget.DrawerLayout;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
public class BaseActivity extends Activity {
public DrawerLayout drawerLayout;
public ListView drawerList;
private String[] drawerListEntries;
private ActionBarDrawerToggle drawerToggle;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_base);
drawerListEntries = getResources().getStringArray(R.array.drawer_items);
drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
drawerToggle = new ActionBarDrawerToggle(this, drawerLayout, R.drawable.ic_navigation_drawer, R.string.drawer_open, R.string.drawer_close)
{
public void onDrawerClosed(View view)
{
getActionBar().setTitle(R.string.app_name);
}
public void onDrawerOpened(View drawerView)
{
getActionBar().setTitle(R.string.hello_world);
}
};
drawerLayout.setDrawerListener(drawerToggle);
getActionBar().setDisplayHomeAsUpEnabled(true);
getActionBar().setHomeButtonEnabled(true);
drawerList = (ListView) findViewById(R.id.drawer_list);
drawerList.setAdapter(new ArrayAdapter<String>(getBaseContext(), R.layout.drawer_list_item, drawerListEntries));
drawerList.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> arg0, View view, int pos, long arg3) {
String selectedValue = (String) drawerList.getAdapter().getItem(pos);
Toast.makeText(getBaseContext(), selectedValue, Toast.LENGTH_SHORT).show();
}
});
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (drawerToggle.onOptionsItemSelected(item)) {
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
drawerToggle.syncState();
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
drawerToggle.onConfigurationChanged(newConfig);
}
#Override
public boolean onPrepareOptionsMenu(Menu menu) {
boolean drawerOpen = drawerLayout.isDrawerOpen(drawerList);
menu.findItem(R.id.action_user).setVisible(!drawerOpen);
return super.onPrepareOptionsMenu(menu);
}
}
This is my activity_base.xml:
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<FrameLayout
android:id="#+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<ListView
android:id="#+id/drawer_list"
android:layout_width="240dp"
android:layout_height="wrap_content"
android:background="#color/light_blue"
android:divider="#android:color/transparent"
android:dividerHeight="0dp"
android:choiceMode="singleChoice"
android:layout_gravity="start"
/>
</android.support.v4.widget.DrawerLayout>
This is my drawer_list_item.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/drawer_list_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:layout_marginTop="12dp"
android:textSize="24sp"
android:textColor="#color/belize_hole"
android:fontFamily="sans-serif-light">
</TextView>
</LinearLayout>
And this is my MainActivity.java which extends BaseActivity:
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class HomeActivity extends BaseActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.home, menu);
//return super.onCreateOptionsMenu(menu);
return true;
}
}
Anyone who can see the problem?

You are overriding content view from BaseActivity by calling setContentView(R.layout.activity_home); in HomeActivity.
I suggest you to switch fragments instead of activities with Navigation Drawer, it's the best way. So you will have one hosting activity with Navigation Drawer and you'll switch only views inside FrameLayout, for instance. Take a look here http://developer.android.com/training/implementing-navigation/nav-drawer.html