How to initiate TextView in a fragment?

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I am new to fragments and have the following code:

public class TripleTab1 extends Fragment {

private TextView nameAndNumberText;
private Map<String, String> nameToNumberMapping;

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

    nameAndNumberText = (TextView) getActivity().findViewById(R.id.numberToNameView);
    nameToNumberMapping = ContactNameAndNumberUtility
            .getNameToPhoneNumberMapping(getActivity()
            .getApplicationContext());

    for (Map.Entry<String, String> item : nameToNumberMapping.entrySet()) {
        String key = item.getKey();
        String value = item.getValue();

        nameAndNumberText.append(key);
        nameAndNumberText.append(value);
    }
    return inflater.inflate(R.layout.assign_pattern_tab_1, container, false);

}

}

Unfortunately, this gives me a NullPointerException. It seems like the TextView object is not initiated, even though I believe it should be.

"java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.append(java.lang.CharSequence)' on a null object reference"

Does anyone know what could be wrong?


Replace your code with this

    @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState){
    View view =inflater.inflate(R.layout.assign_pattern_tab_1, container, false);
    nameAndNumberText = (TextView) view.findViewById(R.id.numberToNameView);
    nameToNumberMapping = ContactNameAndNumberUtility
            .getNameToPhoneNumberMapping(getActivity()
            .getApplicationContext());

    for (Map.Entry<String, String> item : nameToNumberMapping.entrySet()) {
        String key = item.getKey();
        String value = item.getValue();

        nameAndNumberText.append(key);
        nameAndNumberText.append(value);
    }
    return view;

What is different between getContext and getActivity from Fragment , TextView; public class FirstFragment extends Fragment { @Override To run the app from android studio, open one of your project's activity  When developing any application which isn’t a Hello World, then chances are that you will need to have more than one Activity or Fragments.Fragments basically are subactivities. Most newbies get confused with passing data between activities or between fragments.


you should do like this:

Need to pass view to your widgets instead of activity and you are inflating your view at the end take it to the top.

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState){
  View v = inflater.inflate(R.layout.assign_pattern_tab_1, container, false);
 nameAndNumberText = (TextView) v.findViewById(R.id.numberToNameView);
nameToNumberMapping = ContactNameAndNumberUtility
        .getNameToPhoneNumberMapping(getActivity()
        .getApplicationContext());

for (Map.Entry<String, String> item : nameToNumberMapping.entrySet()) {
    String key = item.getKey();
    String value = item.getValue();

    nameAndNumberText.append(key);
    nameAndNumberText.append(value);
}
return v;

Using Fragments in Android - A Worked Example, Before you begin this lesson, you must set up your Android project to use the Support Library. If you have not used the Support Library before, set  Name the file text_fragment.xml and click Finish. When the layout loads into the Graphical Layout tool, change to the XML view by clicking on the text_fragment.xml tab at the bottom of the layout panel. Modify the XML to add a TextView to the fragment layout as follows:


You need to create a View first

View view = inflater.inflate(R.layout.assign_pattern_tab_1, container,false); 
nameAndNumberText = (TextView) view.findViewById(R.id.numberToNameView);
        nameToNumberMapping = ContactNameAndNumberUtility
                .getNameToPhoneNumberMapping(getActivity()
                .getApplicationContext());

        for (Map.Entry<String, String> item : nameToNumberMapping.entrySet()) {
            String key = item.getKey();
            String value = item.getValue();

            nameAndNumberText.append(key);
            nameAndNumberText.append(value);
        }
        return inflater.inflate(R.layout.assign_pattern_tab_1, container, false);

How to use findViewById in Fragment?, This is also sometimes called Adding a Fragment Statically. To do this, open activity_main.xml, select the Text tab and add the following inside  Open the activity_main.xml, delete the TextView and change the root ViewGroup contain to RelativeLayout. Then, switch to the design view of the Android Studio if you are not using it already. In the custom section, click on the <fragment> menu to open is pop-up window. Select the FirstFragment and click Ok.


You should do like this:-

public class TripleTab1 extends Fragment {

private TextView nameAndNumberText;
private Map<String, String> nameToNumberMapping;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState){
View v = inflater.inflate(R.layout.assign_pattern_tab_1, container, false);
    nameAndNumberText = (TextView) v.findViewById(R.id.numberToNameView);
    nameToNumberMapping = ContactNameAndNumberUtility
            .getNameToPhoneNumberMapping(getActivity()
            .getApplicationContext());

    for (Map.Entry<String, String> item : nameToNumberMapping.entrySet()) {
        String key = item.getKey();
        String value = item.getValue();

        nameAndNumberText.append(key);
        nameAndNumberText.append(value);
    }
    return v;

}

Create a fragment, Creating and Using Fragments Begin the transaction FragmentTransaction ft android:layout_height="wrap_content" android:text="I am the parent fragment"  In the previous post, you learnt how to create fragments and replace one fragment by another fragment. In this Android tip, I will show you how to send an intent from a fragment to an activity. Sending an intent from a fragment to an activity is almost the same as sendin


Android Fragments Tutorial: An Introduction with Kotlin , In this article we'll discuss on implementing android fragments using Fragment class FirstFragment : Fragment() { lateinit var textView: As we initialize our views in onCreate() method, here we can do the same things. The fragment you want to start could also live in another activity. In that case, in the onClick() callback you use an Intent to start that activity and then you can use a FragmentTransaction to start your fragment dynamically similar to the code above. Let me know if you have any questions.


Creating and Using Fragments, Add the following code to the Fragment's onCreateView method: final TextView tv​=new TextView(getActivity()); tv.setText("Text Entry"); linLayout. (A Fragment can also be used without a UI, in order to retain values across configuration changes, but this lesson does not cover that usage.) A Fragment can be a static part of the UI of an Activity, which means that the Fragment remains on the screen during the entire lifecycle of the Activity.


Understanding Android Fragments with Example, How to Add TextView Inside Fragments Android - Text to Speech How to open a fragment Duration: 8:49 Posted: Apr 2, 2018 The UI for the first fragment will contain an EditText view and a Button and the second fragment will contain a TextView object. The two fragments will be embedded within the main activity of the application and when the button in the first fragment is pressed, the text entered into the EditText view will appear on the TextView of the second