Develop Reference

How do I get my app to run with navigation view?

I am trying to add a navigational menu to my app and I am following the Create a navigation drawer at https://developer.android.com/training/implementing-navigation/nav-drawer
When i try to run the app I get as far as seeing a blank white screen than the app closes.
I don't have any errors in my code or when it gets compiled, it just wont load the main page.
package com.example.troubleshootonly.americanharvest
import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import com.example.troubleshootonly.americanharvest.R.layout.activity_main
var pass: String = ""
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(activity_main)
//these create buttons with buttF being the name of the button
//everything in brackets is the function, which starts activity
/*
buttF.setOnClickListener {
startActivity(Intent(this, Activity2::class.java))
}
buttE.setOnClickListener {
startActivity(Intent(this, Activity3::class.java))
}
buttC.setOnClickListener {
startActivity(Intent(this, Activity4::class.java))
}
*/
/* admin stuff
admin.setOnClickListener {
val tempPw = adminPass.text.trim().toString()
if (tempPw.equals(pass, true)) {
startActivity(Intent(this, adminPage::class.java))
} else {
startActivity(Intent(this, MainActivity::class.java))
}
}
*/
}
}
this is my main activity page
xmlns:tools="http://schemas.android.com/tools" android:id="#+id/mainPage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:fitsSystemWindows="true" tools:openDrawer="start"
android:visibility="visible">
<FrameLayout
android:id="#+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/ahlogo" android:visibility="visible"/>
<android.support.design.widget.NavigationView
android:layout_width="wrap_content"
android:layout_gravity="start"
android:layout_height="wrap_content" android:id="#+id/menuMain"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:layout_marginEnd="44dp" android:layout_marginRight="44dp"
app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintVertical_bias="0.0"
app:menu="#menu/drawer_view" android:fitsSystemWindows="false">
</android.support.design.widget.NavigationView>
</android.support.v4.widget.DrawerLayout>
logcat:
--------- beginning of crash
2019-01-12 20:20:45.486 13641-13641/com.example.troubleshootonly.americanharvest E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.troubleshootonly.americanharvest, PID: 13641
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.troubleshootonly.americanharvest/com.example.troubleshootonly.americanharvest.MainActivity}: android.view.InflateException: Binary XML file line #16: Binary XML file line #16: Error inflating class android.support.design.widget.NavigationView
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2913)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
Caused by: android.view.InflateException: Binary XML file line #16: Binary XML file line #16: Error inflating class android.support.design.widget.NavigationView
Caused by: android.view.InflateException: Binary XML file line #16: Error inflating class android.support.design.widget.NavigationView
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Constructor.newInstance0(Native Method)
at java.lang.reflect.Constructor.newInstance(Constructor.java:343)
at android.view.LayoutInflater.createView(LayoutInflater.java:647)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:790)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:730)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:863)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:824)
at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
at android.support.v7.app.AppCompatDelegateImpl.setContentView(AppCompatDelegateImpl.java:469)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
at com.example.troubleshootonly.americanharvest.MainActivity.onCreate(MainActivity.kt:13)
at android.app.Activity.performCreate(Activity.java:7136)
at android.app.Activity.performCreate(Activity.java:7127)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1271)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2893)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
Caused by: android.content.res.Resources$NotFoundException: Resource ID #0x7f0c0000
at android.content.res.ResourcesImpl.getValue(ResourcesImpl.java:216)
at android.content.res.Resources.loadXmlResourceParser(Resources.java:2155)
at android.content.res.Resources.getLayout(Resources.java:1155)
2019-01-12 20:20:45.487 13641-13641/com.example.troubleshootonly.americanharvest E/AndroidRuntime: at android.support.v7.view.SupportMenuInflater.inflate(SupportMenuInflater.java:125)
at android.support.design.widget.NavigationView.inflateMenu(NavigationView.java:264)
at android.support.design.widget.NavigationView.<init>(NavigationView.java:189)
at android.support.design.widget.NavigationView.<init>(NavigationView.java:104)
... 28 more
--------- beginning of system

The code is unclear and also some line of code is missing. Like i cant see the start of Drawer layout.
Also you have not Declared the Drawer Layout and NavigationView in your MainActivity.java, As you have not provided code clearly. Hence I have provided you the main files needed to implement navigation drawer. Just copy paste as it is (expect package name :p).
MainActivity.java (I named it navBar.java)
public class navBar extends AppCompatActivity {
private DrawerLayout drawerLayout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_nav_bar);
drawerLayout = findViewById(R.id.drawer_layout_tab_bar);
NavigationView navigationView = findViewById(R.id.navigation_view_tab_bar_activity);
navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
// set item as selected to persist highlight
menuItem.setChecked(true);
// close drawer when item is tapped
drawerLayout.closeDrawers();
// Add code here to update the UI based on the item selected
// For example, swap UI fragments here
return true;
}
});
}
}
activity_main.xml (I named it activity_nav_bar)
public class navBar extends AppCompatActivity {
private DrawerLayout drawerLayout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_nav_bar);
drawerLayout = findViewById(R.id.drawer_layout_tab_bar);
NavigationView navigationView = findViewById(R.id.navigation_view_tab_bar_activity);
navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
// set item as selected to persist highlight
menuItem.setChecked(true);
// close drawer when item is tapped
drawerLayout.closeDrawers();
// Add code here to update the UI based on the item selected
// For example, swap UI fragments here
return true;
}
});
}
}
Add these to your app gradle file (If not present)
implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'com.android.support:design:28.0.0'
Use this as menu file to show content in nav_bar.
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android" >
<group android:checkableBehavior="single">
<item
android:id="#+id/nav_profile"
android:icon="#drawable/ic_baseline_account_circle_24px"
android:title="#string/profile" />
<item
android:id="#+id/nav_templates"
android:icon="#drawable/ic_baseline_create_24px"
android:title="#string/temp" />
<item
android:id="#+id/nav_logout"
android:icon="#drawable/ic_baseline_exit_to_app_24px"
android:title="#string/log_out" />
</group>
</menu>
Hope this helps.

Implementing a WebView within a CardView using a RecyclerView [duplicate]

This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 5 years ago.
I am using a WebView within a CardView with Recyclerview.
I implemented them correctly, but the problem is that when I run application it crashes and shows a nullpointer exception,
Log crash report:
java.lang.RuntimeException: Unable to start activity ComponentInfo{andro.petrochemical/andro.petrochemical.webViewNews}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.webkit.WebView.setWebViewClient(android.webkit.WebViewClient)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.webkit.WebView.setWebViewClient(android.webkit.WebViewClient)' on a null object reference
at andro.petrochemical.webViewNews.onCreate(webViewNews.java:33)
at android.app.Activity.performCreate(Activity.java:6662)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2599)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707) 
at android.app.ActivityThread.-wrap12(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:154) 
at android.app.ActivityThread.main(ActivityThread.java:6077) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755) 
WebView CardView xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<WebView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/webView_news"/>
</LinearLayout>
</android.support.v7.widget.CardView>
RecyclerView 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"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layoutManager="android.support.v7.widget.LinearLayoutManager"
android:id="#+id/resycleWeb"/>
</LinearLayout>
WebView java class file:
public class webViewNews extends AppCompatActivity {
private WebView webviewthis;
private RecyclerView webVieRes;
private DatabaseReference mdataRef;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.webview_page);
webVieRes = (RecyclerView) findViewById(R.id.resycleWeb);
mdataRef = FirebaseDatabase.getInstance().getReference().child("weber");
webviewthis = (WebView)findViewById(R.id.webView_news);
webviewthis.setWebViewClient(new WebViewClient());
webviewthis.getSettings().setJavaScriptEnabled(true);
webviewthis.getSettings().setLoadsImagesAutomatically(true);
}
#Override
public void onStart() {
super.onStart();
FirebaseRecyclerAdapter<post2web,post2webViewHolder> firebaseRecyclerAdapte = new FirebaseRecyclerAdapter<post2web,post2webViewHolder>(
post2web.class,
R.layout.web_card,
post2webViewHolder.class,
mdataRef
) {
#Override
protected void populateViewHolder(post2webViewHolder viewHolder, post2web model, int position) {
viewHolder.setWebViewPost(model.getWebViewPost());
}
};
webVieRes.setAdapter(firebaseRecyclerAdapte);
}
public static class post2webViewHolder extends RecyclerView.ViewHolder {
View mVie;
public post2webViewHolder(View itemView) {
super(itemView);
mVie = itemView;
}
public void setWebViewPost(String webViewPost) {
WebView post_web = (WebView) mVie.findViewById(R.id.webView_news);
post_web.loadUrl(webViewPost);
}
}
}

Remove webview initialization from onCreate()
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.webview_page);
webVieRes = (RecyclerView) findViewById(R.id.resycleWeb);
mdataRef = FirebaseDatabase.getInstance().getReference().child("weber");
}
And update in post2webViewHolder
public void setWebViewPost(String webViewPost) {
WebView post_web = (WebView) mVie.findViewById(R.id.webView_news);
post_web.loadUrl(webViewPost);
post_web.setWebViewClient(new WebViewClient());
post_web.getSettings().setJavaScriptEnabled(true);
post_web.getSettings().setLoadsImagesAutomatically(true);
}

You need to only find the WebView from the post2webViewHolder
It's not part of the Activity, therefore it's null
Remove webviewthis

Go from activity to fragment and to another fragment

I am new at android and I can't seem to understand one thing.
I am trying to jump from MainActivity to MainFragment. In it there is a button. When onClickListener is triggered, it should jump to another ResultFragment. But I can't seem to understand how to do it.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.something.MainActivity">
<fragment
android:id="#+id/container"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
tools:layout="#layout/fragment_main" />
</RelativeLayout>
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Fragment fragment = new MainFragment();
getSupportFragmentManager().beginTransaction().replace(R.id.container, fragment, null).commit();
}
}
public class MainFragment extends Fragment {
public MainFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
Button button = (Button) rootView.findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(getContext(), "iskviesta", Toast.LENGTH_SHORT).show();
getFragmentManager().beginTransaction().replace(R.id.container, new ResultFragment()).commit();
}
});
return rootView;
}
}
public class ResultFragment extends Fragment {
public ResultFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_result, container, false);
return rootView;
}
}
What am I doing wrong? The app doesn't even start.
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.something, PID: 14245
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.something/com.something.MainActivity}: android.view.InflateException: Binary XML file line #13: Binary XML file line #13: Error inflating class fragment
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2665)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6119)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
Caused by: android.view.InflateException: Binary XML file line #13: Binary XML file line #13: Error inflating class fragment
Caused by: android.view.InflateException: Binary XML file line #13: Error inflating class fragment
Caused by: java.lang.NullPointerException
at java.lang.VMClassLoader.findLoadedClass(Native Method)
at java.lang.ClassLoader.findLoadedClass(ClassLoader.java:742)
at java.lang.ClassLoader.loadClass(ClassLoader.java:362)
at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
at android.support.v4.app.Fragment.isSupportFragmentClass(Fragment.java:459)
at android.support.v4.app.FragmentManagerImpl.onCreateView(FragmentManager.java:3321)
at android.support.v4.app.FragmentController.onCreateView(FragmentController.java:120)
at android.support.v4.app.FragmentActivity.dispatchFragmentsOnCreateView(FragmentActivity.java:378)
at android.support.v4.app.BaseFragmentActivityHoneycomb.onCreateView(BaseFragmentActivityHoneycomb.java:33)
at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:79)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:777)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:727)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:858)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:821)
at android.view.LayoutInflater.inflate(LayoutInflater.java:518)
at android.view.LayoutInflater.inflate(LayoutInflater.java:426)
at android.view.LayoutInflater.inflate(LayoutInflater.java:377)
at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:288)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:143)
at com.something.MainActivity.onCreate(MainActivity.java:12)
at android.app.Activity.performCreate(Activity.java:6679)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2618)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6119)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)

In your xml use a FrameLayout instead of Fragment:
<FrameLayout
android:id="#+id/container"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
Using a fragment tag will not allow you to do fragment transactions on the view.

You should use getSupportFragmentManager() instead of getFragmentManager in your listener :
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(getContext(), "iskviesta", Toast.LENGTH_SHORT).show();
getSupportFragmentManager().beginTransaction().replace(R.id.container, new ResultFragment()).commit();
}
});
And remplace your fragment layout with a FrameLayout in your xml code.
Hope this helps.
Sorry for my english.

Fragments in AppCompatActivity

Could I use this extension if I want to use Fragments in my swipe view activity?
public class Overview_Screen extends AppCompatActivity {
My Fragment classes use this one:
public class MessagesFragmentPortrait extends android.support.v4.app.Fragment {
I am asking this because my app keeps crashing...
Here is my main Activity:
public class Overview_Screen extends AppCompatActivity {
private SectionsPagerAdapter mSectionsPagerAdapter;
private ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_overview_screen);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.container);
mViewPager.setAdapter(mSectionsPagerAdapter);
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(mViewPager);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_overview_screen, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
Intent settings_intent = new Intent(this, Settings_Screen.class);
startActivity(settings_intent);
return true;
}
return super.onOptionsItemSelected(item);
}
public static class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int i) {
switch (i) {
case 0:
return new AccountFragmentPortrait();
case 1:
return new FeedFragmentPortrait();
default:
return new MessagesFragmentPortrait();
}
}
#Override
public int getCount() {
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return "Account";
case 1:
return "Feed";
case 2:
return "Messages";
}
return null;
}
}
}
and here is my stack trace:
FATAL EXCEPTION: main
Process: de.lukas_schroederoutlook.connect, PID: 3364
java.lang.RuntimeException: Unable to start activity ComponentInfo{de.lukas_schroederoutlook.connect/de.lukas_schroederoutlook.connect.Overview_Screen}:
android.view.InflateException: Binary XML file line #41: Binary XML file line #41: Error inflating class fragment
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2665)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6119)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
Caused by: android.view.InflateException: Binary XML file line #41: Binary XML file line #41: Error inflating class fragment
Caused by: android.view.InflateException: Binary XML file line #41: Error inflating class fragment
Caused by: java.lang.NullPointerException
at java.lang.VMClassLoader.findLoadedClass(Native Method)
at java.lang.ClassLoader.findLoadedClass(ClassLoader.java:742)
at java.lang.ClassLoader.loadClass(ClassLoader.java:362)
at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
at android.support.v4.app.Fragment.isSupportFragmentClass(Fragment.java:469)
at android.support.v4.app.FragmentManagerImpl.onCreateView(FragmentManager.java:2384)
at android.support.v4.app.FragmentController.onCreateView(FragmentController.java:120)
at android.support.v4.app.FragmentActivity.dispatchFragmentsOnCreateView(FragmentActivity.java:378)
at android.support.v4.app.BaseFragmentActivityHoneycomb.onCreateView(BaseFragmentActivityHoneycomb.java:33)
at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:77)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:777)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:727)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:858)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:821)
at android.view.LayoutInflater.inflate(LayoutInflater.java:518)
at android.view.LayoutInflater.inflate(LayoutInflater.java:426)
at android.view.LayoutInflater.inflate(LayoutInflater.java:377)
at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:284)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:143)
at de.lukas_schroederoutlook.connect.Overview_Screen.onCreate(Overview_Screen.java:42)
at android.app.Activity.performCreate(Activity.java:6679)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2618)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6119)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
And lastly, here is my overview screen xml:
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="de.lukas_schroederoutlook.connect.Overview_Screen">
<android.support.design.widget.AppBarLayout
android:id="#+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="#dimen/appbar_padding_top"
android:theme="#style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways"
app:popupTheme="#style/AppTheme.PopupOverlay">
</android.support.v7.widget.Toolbar>
<android.support.design.widget.TabLayout
android:id="#+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
<fragment
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/feed_fragment_portrait"/>
<fragment
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/feed_fragment_landscape"/>
And my overview screen fragment xml:
<RelativeLayout 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:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="de.lukas_schroederoutlook.connect.Overview_Screen$PlaceholderFragment">
<TextView
android:id="#+id/section_label"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />

You need to specify a class attribute in your <fragment> tags.
<fragment
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/feed_fragment_portrait"/>
<fragment
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/feed_fragment_landscape"/>
Add a class="your.packagename.SomeFragment" on both of those (if you actually need both... Typically you have different layout files for landspace and portrait, not have both in one)
It looks like you are using a ViewPager, though, so do you really need the <fragment> tags at all? I think you can remove them.

You need something like this:
<fragment
android:name="de.lukas_schroederoutlook.connect.FeedFragmentPortrait"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/feed_fragment_portrait"/>
Or use
class=
as cricket said.

Android Hide ActionBar while scrolling in a ListView

I am looking for a method to hide actionbar like GooglePlay, when scrolling down and let the ActionBar reappear when scrolling up. I have found a lot of guides but them are about recyclerview and I am using listview.
The best guide I found is this: https://mzgreen.github.io/2015/06/23/How-to-hideshow-Toolbar-when-list-is-scrolling%28part3%29/.
This is my layout:
<?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/coordinatorLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ListView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/FList" />
<android.support.design.widget.AppBarLayout
android:id="#+id/appBarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"/>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/viewPager"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</android.support.design.widget.CoordinatorLayout>
This is my error:
Process: com.mycompany.test, PID: 6172
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mycompany.test/com.mycompany.test.activities.Friends_List_Activity}: android.view.InflateException: Binary XML file line #2: Error inflating class android.support.design.widget.CoordinatorLayout
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2329)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2389)
at android.app.ActivityThread.access$900(ActivityThread.java:147)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1296)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:898)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:693)
at de.robv.android.xposed.XposedBridge.main(XposedBridge.java:117)
Caused by: android.view.InflateException: Binary XML file line #2: Error inflating class android.support.design.widget.CoordinatorLayout
at android.view.LayoutInflater.createView(LayoutInflater.java:633)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:743)
at android.view.LayoutInflater.inflate(LayoutInflater.java:482)
at de.robv.android.xposed.XposedBridge.invokeOriginalMethodNative(Native Method)
at de.robv.android.xposed.XposedBridge.handleHookedMethod(XposedBridge.java:684)
at android.view.LayoutInflater.inflate(Unknown Source)
at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:428)
at android.app.Activity.setContentView(Activity.java:2144)
at com.mycompany.test.activities.Friends_List_Activity.onCreate(Friends_List_Activity.java:26)
at android.app.Activity.performCreate(Activity.java:5933)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2282)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2389)
            at android.app.ActivityThread.access$900(ActivityThread.java:147)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1296)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5254)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:898)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:693)
            at de.robv.android.xposed.XposedBridge.main(XposedBridge.java:117)
EDIT:
Hiding the ActionBar on RecyclerView/ListView onScroll
In the guide above I can't use the code, I need to extend Activity so I am unable to use getSupportActionBar()
EDIT 2.0:
My activity:
public class Contacts_List_Activity extends Activity {
private SearchView mSearchView;
private Contacts_List_Adapter_OBJ ContactsAdapter;
private Menu menu;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_Contacts_list);
ContactsAdapter = new Contacts_List_Adapter_OBJ(this);
final ListView listView = (ListView) findViewById(R.id.Contacts);
listView.setAdapter(ContactsAdapter);
}
#Override
public boolean onCreateOptionsMenu(final Menu menu) {
this.menu = menu;
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_Contact_list_screen, menu);
mSearchView = (SearchView) menu.findItem(R.id.search).getActionView();
mSearchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
#Override
public boolean onQueryTextSubmit(String s) {
return false;
}
#Override
public boolean onQueryTextChange(String s) {
Contacts_List_Adapter_OBJ FilterAdapter = ContactsAdapter;
if (TextUtils.isEmpty(s)) {
FilterAdapter.getFilter().filter("");
} else {
FilterAdapter.getFilter().filter(s.toLowerCase());
}
return true;
}
});
mSearchView.setOnSearchClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Set_MenuItem_Visible(false);
}
});
mSearchView.setOnCloseListener(new SearchView.OnCloseListener() {
#Override
public boolean onClose() {
Set_MenuItem_Visible(true);
return false;
}
});
final MenuItem searchMI = menu.findItem(R.id.search);
mSearchView.setOnQueryTextFocusChangeListener(new View.OnFocusChangeListener() {
#Override
public void onFocusChange(View view, boolean queryTextFocused) {
if (!queryTextFocused) {
searchMI.collapseActionView();
}
}
});
return true;
}
}

This is what I tried with the xml layout and it works :
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
The issue in your case seems to be the base Activity. Extend your Contacts_List_Activity with AppCompatActivity
Updated layout - adding app:layout_scrollFlags="scroll|enterAlways" to toolbar and
app:layout_behavior="#string/appbar_scrolling_view_behavior" to listview
<?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/coordinatorLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ListView
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
android:id="#+id/FList" />
<android.support.design.widget.AppBarLayout
android:id="#+id/appBarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
app:layout_scrollFlags="scroll|enterAlways"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"/>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/viewPager"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</android.support.design.widget.CoordinatorLayout>