Can`t understand how to create a Fragment, my App is crashing

Question

I started studying fragments of android studio and find some tutorials "how to create a fragment". But when I am run my app, it is crushes in emulator without errors. I think some error in MainActivity, but I am not sure

This is my MainActiviti.java:

public class MainActivity extends FragmentActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        FragmentManager fm = getSupportFragmentManager();
        Fragment fragment = fm.findFragmentById(R.id.fragment_container);

        if(fragment == null){
            fragment = new CrimeFragment();
            fm.beginTransaction().add(R.id.fragment_container, fragment).commit();
        }


    }
}

And it`s a code for fragment(CrimeFragment):

public class CrimeFragment extends Fragment {

    private Crime mCrime;
    private EditText mTittleField;


    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mCrime = new Crime();
    }

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {


        View v = inflater.inflate(R.layout.fragment_crime, container, false);
        mTittleField = v.findViewById(R.id.crime_tittle);
        mTittleField.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                mCrime.setmTittle(s.toString());

            }

            @Override
            public void afterTextChanged(Editable s) {

            }
        });
        return v;
    }
}

I think problem in MainActivity.java maybe... This is 2 xml files: activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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/fragment_container">



</FrameLayout>

fragment_crime.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:id="@+id/fr">
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/crime_tittle"
        android:hint="@string/crime_tittle_hint"/>

</LinearLayout>

Hope someone can help me.

THIS IS LOG ERROR

Process: com.hocage.tutorial_2, PID: 10713
    java.lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.EditText
        at com.hocage.tutorial_2.CrimeFragment.onCreateView(CrimeFragment.java:33)
        at androidx.fragment.app.Fragment.performCreateView(Fragment.java:2600)
        at androidx.fragment.app.FragmentManagerImpl.moveToState(FragmentManagerImpl.java:881)
        at androidx.fragment.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManagerImpl.java:1238)
        at androidx.fragment.app.FragmentManagerImpl.moveToState(FragmentManagerImpl.java:1303)
        at androidx.fragment.app.BackStackRecord.executeOps(BackStackRecord.java:439)
        at androidx.fragment.app.FragmentManagerImpl.executeOps(FragmentManagerImpl.java:2079)
        at androidx.fragment.app.FragmentManagerImpl.executeOpsTogether(FragmentManagerImpl.java:1869)
        at androidx.fragment.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManagerImpl.java:1824)
        at androidx.fragment.app.FragmentManagerImpl.execPendingActions(FragmentManagerImpl.java:1727)
        at androidx.fragment.app.FragmentManagerImpl.dispatchStateChange(FragmentManagerImpl.java:2663)
        at androidx.fragment.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManagerImpl.java:2613)
        at androidx.fragment.app.FragmentController.dispatchActivityCreated(FragmentController.java:246)
        at androidx.fragment.app.FragmentActivity.onStart(FragmentActivity.java:542)
        at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1435)
        at android.app.Activity.performStart(Activity.java:8024)
        at android.app.ActivityThread.handleStartActivity(ActivityThread.java:3475)
        at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:221)
        at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:201)
        at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:173)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:223)
        at android.app.ActivityThread.main(ActivityThread.java:7656)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)

Hi, you should also provide your crashlog as it will help to answer your question ! — Jissay, Apr 23 '21 at 08:34
https://stackoverflow.com/questions/907360/explanation-of-classcastexception-in-java — Ryan M, Apr 25 '21 at 22:43

Can`t understand how to create a Fragment, my App is crashing

0 Answers0