How do I access a textview Id from fragment class?-CodePudding

I have a recycler view and a XML file for the recycler view. I have used the recycler views inside the fragment layout. I want to access the textview id from the fragment activity for using fragment transactions.

    var titleTextView = view.findViewById<TextView>(R.id.tvTitle)

    val subjectFragment = SubjectFragment()

    println(titleTextView.text)

the above code provides a null pointer exception

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.samachar, PID: 7038
    java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.CharSequence android.widget.TextView.getText()' on a null object reference
        at com.example.samachar.NewsFragment.onViewCreated(NewsFragment.kt:86)
        at androidx.fragment.app.Fragment.performViewCreated(Fragment.java:2987)
        at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:546)
        at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:282)
        at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2189)
        at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:2100)
        at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:2002)
        at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:3138)
        at androidx.fragment.app.FragmentManager.dispatchActivityCreated(FragmentManager.java:3072)
        at androidx.fragment.app.FragmentController.dispatchActivityCreated(FragmentController.java:251)
        at androidx.fragment.app.FragmentActivity.onStart(FragmentActivity.java:502)
        at androidx.appcompat.app.AppCompatActivity.onStart(AppCompatActivity.java:248)
        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)
I/Process: Sending signal. PID: 7038 SIG: 9

I want to use the fragment manager to use the transactions and switch layouts

//            var fragment = parentFragmentManager?.beginTransaction()
//            fragment?.replace(R.id.newsFrameLayout, subjectFragment)
//            fragment?.commit()

but I cannot seem to access the textview id from the fragment class.

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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:id="@ id/newsItem"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:paddingHorizontal="16dp"
    android:paddingVertical="12dp">

    <TextView
        android:id="@ id/tvTitle"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="@string/title_eg"
        android:textColor="@color/purple_200"
        android:textSize="14sp"
        android:textStyle="bold"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@ id/tvDescription"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="@string/description_eg"
        android:textSize="12sp"
        android:textColor="@color/black"
        android:maxLines="2"
        android:justificationMode="inter_word"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@ id/tvTitle" />

    <TextView
        android:id="@ id/tvCategory"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@color/teal_700"
        android:padding="2dp"
        android:text="@string/category_eg"
        android:textColor="@color/white"
        android:textSize="10sp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@ id/tvDescription" />

    <TextView
        android:id="@ id/tvPublishedDate"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/pub_date_eg"
        android:textSize="10sp"
        app:layout_constraintBottom_toBottomOf="@ id/tvCategory"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@ id/tvDescription" />

</androidx.constraintlayout.widget.ConstraintLayout>

This is the xml layout used in the recycler view of the app

EDIT***

Solved it by using the onClickListener on textview in the adapter class onBindViewHolder function and used activity context for calling the supportFragmentManager.

CodePudding user response：

When you use a recyclerview there isn't a unique tvtitle id available. For each item in the recyclerview there is a tvtitle. Although you can aceess each of them from the recyclerview adapter.

CodePudding user response：

If you want to access any item of recyclerview then you need to create a event at onBindViewHolder . Use interface or lambda funtion for getting every view inside activity or fragment.

if you want views when click event happen then implement clickListener.