Question

I have two Activities. In my main Activity I am creating an intent to start the other one:

Intent intent = new Intent(context, Settings.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);

and here is the code for the second Activity that should start:

public class Settings extends Activity {

    Button settingsBack;
    //Some other layout resources
    final Context context = this;   //Creating reference to this Activity Context

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.help);

        //References to layout resources
        settingsBack = (Button) findViewById(R.id.settingsBack);
        //...
        //-----

        //Assigning listeners to Buttons
        settingsBack.setOnClickListener(listenerBack);
        //-----
    }

    //Button listeners definitions
    final OnClickListener listenerBack = new OnClickListener() {

        public void onClick(View v) {
            finish();
        }

    };    
    //-----

}

But when this second Activity should start, I get a NullPointerException at the line, where I assign Listener to the Button. I tried to clean the project in case the R file hasnt generated properly but it didnt solve the problem. The second Activity is declared in manifest file:

<activity android:name=".Settings" android:label="@string/app_name"></activity>

Im sure its just a simple little problem somewhere but I just cant find it 🙁 Thanks for your help!

Answer 1

I do this all the time, I copy an activities onCreate method to a new activity but forget to change the XML file in the setContentView.

I am guessing as the activity is called Settings, but the XML is called help you might have done the same!?