android studio navigtion not woring when movieng with fragments in java

Question

so i wanted to creat a footer navigtion on the main activity and a fragment view above it but now when i try to use the normal navigtion with the navigtion grafh it just crashes. mainActivity java code:

package com.example.mywatchlist;

import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.FragmentActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {
    

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


        Button homeBtn = findViewById(R.id.homeBtn);
        Button profileBtn = findViewById(R.id.profileBtn);
        Button socialBtn = findViewById(R.id.theSocialSearchBtn);
        Button contentBtn = findViewById(R.id.contentContentSearchBtn);



        homeBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                homeFragment home = new homeFragment();
                getSupportFragmentManager().beginTransaction().replace(R.id.fragmentContainerView,home).commit();
            }
        });

        profileBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                userProfileFragment profile = new userProfileFragment();
                getSupportFragmentManager().beginTransaction().replace(R.id.fragmentContainerView,profile).commit();
            }
        });

        socialBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                socialSearchFragment social = new socialSearchFragment();
                getSupportFragmentManager().beginTransaction().replace(R.id.fragmentContainerView,social).commit();
            }
        });

        contentBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                contentSearchFragment contentSearch = new contentSearchFragment();
                getSupportFragmentManager().beginTransaction().replace(R.id.fragmentContainerView,contentSearch).commit();
            }
        });


    }

}

main activity.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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/fragmentContainerView"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="match_parent"
        android:layout_height="632dp"
        app:defaultNavHost="true"
        app:navGraph="@navigation/navigation" />

    <LinearLayout
        android:id="@+id/footer"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal">

        <Button
            android:id="@+id/homeBtn"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="Go to\nHome"
            android:textSize="12dp" />

        <Button
            android:id="@+id/profileBtn"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="My\nProfile"
            android:textSize="12dp" />

        <Button
            android:id="@+id/theSocialSearchBtn"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="Search for\nPeople"
            android:textSize="12dp" />

        <Button
            android:id="@+id/contentContentSearchBtn"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="Search for\nContent"
            android:textSize="12dp" />
    </LinearLayout>
</LinearLayout>

and now it crashes when i try to move in this fragment: fragment to move from java code:

package com.example.mywatchlist;

import android.os.Bundle;

import androidx.fragment.app.Fragment;
import androidx.navigation.Navigation;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;

/**
 * A simple {@link Fragment} subclass.
 * Use the {@link contentSearchFragment#newInstance} factory method to
 * create an instance of this fragment.
 */
public class contentSearchFragment extends Fragment {

    // TODO: Rename parameter arguments, choose names that match
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";

    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;

    public contentSearchFragment() {
        // Required empty public constructor
    }

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @param param1 Parameter 1.
     * @param param2 Parameter 2.
     * @return A new instance of fragment contentSearchFragment.
     */
    // TODO: Rename and change types and number of parameters
    public static contentSearchFragment newInstance(String param1, String param2) {
        contentSearchFragment fragment = new contentSearchFragment();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_content_search,container, false);
        // Inflate the layout for this fragment


        Button searchBtn = view.findViewById(R.id.contentContentSearchBtn);

        searchBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                Navigation.findNavController(view).navigate(R.id.action_contentSearchFragment_to_contentFragment);

            }
        });


        return view;
    }
}

and this is the xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical"
    tools:context=".contentSearchFragment" >

    <TextView
        android:id="@+id/contentSearchTitle"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#C4FF80"
        android:gravity="center"
        android:text="Content search"
        android:textSize="30dp" />

    <Button
        android:id="@+id/contentSearchAddNewContent"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Add new content" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#FFEB3B"
        android:orientation="horizontal">

        <EditText
            android:id="@+id/contentSearchBar"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:background="#C8C8C8"
            android:ems="10"
            android:hint="Search for content"
            android:inputType="textPersonName"
            android:minHeight="48dp" />

        <Button
            android:id="@+id/contentContentSearchBtn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="Search" />
    </LinearLayout>

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="502dp">

        <TextView
            android:id="@+id/contentSearchData"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:text="test\ntest\ntest\ntest\ntest\ntest\XXXXXXXXXXXXXXXXXXntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\nXXXXXXXXXXXXXXXXX test\ntest\nXXXXXXXXXXXXXXXX\ntest\ntest\ntest\ntest\ntesttest\ntest\ntest\ntest\ntest\ntest\XXXXXXXXXXXXXXXXXXntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\nXXXXXXXXXXXXXXXXX test\ntest\nXXXXXXXXXXXXXXXX\ntest\ntest\ntest\ntest\ntesttest\ntest\ntest\ntest\ntest\ntest\XXXXXXXXXXXXXXXXXXntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\nXXXXXXXXXXXXXXXXX test\ntest\nXXXXXXXXXXXXXXXX\ntest\ntest\ntest\ntest\ntesttest\ntest\ntest\ntest\ntest\ntest\XXXXXXXXXXXXXXXXXXntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\nXXXXXXXXXXXXXXXXX test\ntest\nXXXXXXXXXXXXXXXX\ntest\ntest\ntest\ntest\ntesttest\ntest\ntest\ntest\ntest\ntest\XXXXXXXXXXXXXXXXXXntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\nXXXXXXXXXXXXXXXXX test\ntest\nXXXXXXXXXXXXXXXX\ntest\ntest\ntest\ntest\ntesttest\ntest\ntest\ntest\ntest\ntest\XXXXXXXXXXXXXXXXXXntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\nXXXXXXXXXXXXXXXXX test\ntest\nXXXXXXXXXXXXXXXX\ntest\ntest\ntest\ntest\ntesttest\ntest\ntest\ntest\ntest\ntest\XXXXXXXXXXXXXXXXXXntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\nXXXXXXXXXXXXXXXXX test\ntest\nXXXXXXXXXXXXXXXX\ntest\ntest\ntest\ntest\ntesttest\ntest\ntest\ntest\ntest\ntest\XXXXXXXXXXXXXXXXXXntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\ntest\nXXXXXXXXXXXXXXXXX test\ntest\nXXXXXXXXXXXXXXXX\ntest\ntest\ntest\ntest\ntest" />
    </ScrollView>

</LinearLayout>

and this is the navigtion xml:

<?xml version="1.0" encoding="utf-8"?>
<navigation 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/navigation"
    app:startDestination="@id/startFragment">
    <fragment
        android:id="@+id/startFragment"
        android:name="com.example.mywatchlist.startFragment"
        android:label="fragment_start"
        tools:layout="@layout/fragment_start" >
        <action
            android:id="@+id/action_startFragment_to_logInFragment"
            app:destination="@id/logInFragment" />
        <action
            android:id="@+id/action_startFragment_to_registerFragment"
            app:destination="@id/registerFragment" />
    </fragment>
    <fragment
        android:id="@+id/logInFragment"
        android:name="com.example.mywatchlist.logInFragment"
        android:label="fragment_log_in"
        tools:layout="@layout/fragment_log_in" >
        <action
            android:id="@+id/action_logInFragment_to_homeFragment"
            app:destination="@id/homeFragment" />
    </fragment>
    <fragment
        android:id="@+id/registerFragment"
        android:name="com.example.mywatchlist.registerFragment"
        android:label="fragment_register"
        tools:layout="@layout/fragment_register" >
        <action
            android:id="@+id/action_registerFragment_to_homeFragment"
            app:destination="@id/homeFragment" />
    </fragment>
    <fragment
        android:id="@+id/homeFragment"
        android:name="com.example.mywatchlist.homeFragment"
        android:label="fragment_home"
        tools:layout="@layout/fragment_home" />
    <fragment
        android:id="@+id/userProfileFragment"
        android:name="com.example.mywatchlist.userProfileFragment"
        android:label="fragment_user_profile"
        tools:layout="@layout/fragment_user_profile" />
    <fragment
        android:id="@+id/contentFragment"
        android:name="com.example.mywatchlist.contentFragment"
        android:label="fragment_content"
        tools:layout="@layout/fragment_content" />
    <fragment
        android:id="@+id/contentSearchFragment"
        android:name="com.example.mywatchlist.contentSearchFragment"
        android:label="fragment_content_search"
        tools:layout="@layout/fragment_content_search" >
        <action
            android:id="@+id/action_contentSearchFragment_to_contentFragment"
            app:destination="@id/contentFragment" />
    </fragment>
    <fragment
        android:id="@+id/socialSearchFragment"
        android:name="com.example.mywatchlist.socialSearchFragment"
        android:label="fragment_social_search"
        tools:layout="@layout/fragment_social_search" >
        <action
            android:id="@+id/action_socialSearchFragment_to_userProfileFragment"
            app:destination="@id/userProfileFragment" />
    </fragment>
</navigation>

crashing:

    --------- beginning of crash
2022-07-01 14:32:49.986 25363-25363/com.example.mywatchlist E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.mywatchlist, PID: 25363
    java.lang.IllegalStateException: View com.google.android.material.button.MaterialButton{3bedc11 VFED..C.. ...P.... 921,5-1440,173 #7f080237 app:id/contentContentSearchBtn} does not have a NavController set
        at androidx.navigation.Navigation.findNavController(Navigation.kt:71)
        at com.example.mywatchlist.contentSearchFragment$1.onClick(contentSearchFragment.java:73)
        at android.view.View.performClick(View.java:7448)
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1194)
        at android.view.View.performClickInternal(View.java:7425)
        at android.view.View.access$3600(View.java:810)
        at android.view.View$PerformClick.run(View.java:28305)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:223)
        at android.app.ActivityThread.main(ActivityThread.java:7656)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
2022-07-01 14:32:50.027 25363-25363/com.example.mywatchlist I/Process: Sending signal. PID: 25363 SIG: 9

thank you to all the helpers

score 0 · Answer 1 · answered Jul 01 '22 at 11:40

0

can you please share the crashing error? It's hard to figure out the error. If you can also add how to reproduce the crash it can be very helpful

answered Jul 01 '22 at 11:40

TzlilSwi

94
6

add it just now – itay bielski Jul 01 '22 at 11:46
Please check this issue, I think you can find the solution there: https://stackoverflow.com/questions/50502269/illegalstateexception-link-does-not-have-a-navcontroller-set – TzlilSwi Jul 01 '22 at 11:51
that answer is in cotlin im using java – itay bielski Jul 01 '22 at 11:56
Just Use `Navigation.findNavController(view).navigate(R.id.viewTransactionsAction); ` – Pratik Fagadiya Jul 01 '22 at 12:18
for more info refer this - https://developer.android.com/guide/navigation/navigation-navigate#id – Pratik Fagadiya Jul 01 '22 at 12:18

Pratik Fagadiya · Answer 2 · 2022-07-01T12:05:24.223

0

You forgot to initialize NavHostFragent

so kindly Initiliaze In your OnCreate

NavHostFragment navHostFragment = (NavHostFragment) getSupportFragmentManager()
            .findFragmentById(R.id. fragmentContainerView);
NavController navController = navHostFragment.getNavController();

and for the navigate one fragment to another fragment use navigate

 homeBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {navController.navigate(R.id. action_startFragment_to_registerFragment
            }
        });)

edited Jul 01 '22 at 12:05

answered Jul 01 '22 at 12:00

Pratik Fagadiya

1,195
7
21

in what onCreate? mainActivity or the fragment ? – itay bielski Jul 01 '22 at 12:04
In MainActivity – Pratik Fagadiya Jul 01 '22 at 12:05
the onClick for the button is in the fragment so how do i get the navController there? – itay bielski Jul 01 '22 at 12:12
i also now tryed using a func to use the navigtion action and from the fragment it just valls that func' and still craching – itay bielski Jul 01 '22 at 12:15

android studio navigtion not woring when movieng with fragments in java

2 Answers2