Geek Answers Handbook

I added a spinner to the application, but activity does not start due to adapter code

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.rishabh.casino/com.example.rishabh.casino.Game}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Spinner.setAdapter(android.widget.SpinnerAdapter)' on a null object reference
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2314)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2388)
            at android.app.ActivityThread.access$800(ActivityThread.java:148)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1292)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5312)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:901)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:696)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Spinner.setAdapter(android.widget.SpinnerAdapter)' on a null object reference
+6
source share
6 answers

The main problem: you initialize your counter over your view. You should put setContentView(R.layout.activity_game); on top and after that you should initialize other components. FixonCreate

@Override
                protected void onCreate(Bundle savedInstanceState) {
                   super.onCreate(savedInstanceState);
             setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
                    setContentView(R.layout.activity_game); //Initialize layout first

                    spin=(Spinner)findViewById(R.id.spinner);
                    rembal=(TextView)findViewById(R.id.textView8);
                    bet_amount=(TextView)findViewById(R.id.textView9);
                    beton=(TextView)findViewById(R.id.textView10);
                    result=(TextView)findViewById(R.id.textView11);
                    bet=(EditText)findViewById(R.id.editText2);
                    okgen=(Button)findViewById(R.id.button4);

                    ArrayAdapter<String> adapter_option=new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,options);
                    adapter_option.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
                    spin.setAdapter(adapter_option);
                    spin.setOnItemSelectedListener(this);
                    super.onCreate(savedInstanceState);

                    if (savedInstanceState == null) {
                        getSupportFragmentManager().beginTransaction()
                                .add(R.id.container, new PlaceholderFragment())
                                .commit();
                    }
                }

This is the reason for the null pointer exception. The view has not yet been initialized, and you are trying to initialize the internal view of the hideer.

+7
source

From the error log, it looks like your spinner is null ...

this may be due to the fact that you did not initialize it (using findViewById ("...")), or you did it, but in one of the last calls ...

+3

        Spinner sp;
        sp = (Spinner)findViewById(R.id.spUOM);
        sp.setAdapter(dataAdapter);
        sp.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {


public class Main2Activity

!

0

, onCreate().

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.spinner);//layout
0

, , Logcat

java.lang.NullPointerException: "void android.widget.Spinner.setAdapter(android.widget.SpinnerAdapter)"

onCreate onCreateOptions, :

  @Override
    public boolean onCreateOptionsMenu(Menu menu) {
    Spinner spinner = findViewById(R.id.partNumberRevisionSpinner);
    ArrayAdapter<CharSequence> adapter1 = ArrayAdapter.createFromResource(this, 
     R.array.wos, android.R.layout.simple_spinner_item);
    adapter1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinner.setAdapter(adapter1);
    return true;
}

string.xml

  <string-array name="wos">
    <item>6021665</item>
    <item>6021666</item>
    <item>6021667</item>
    <item>6021668</item>
    <item>6021669</item>
    <item>6021671</item>
    <item>6021672</item>
    <item>6021673</item>
</string-array>

XML

   <Spinner
        android:id="@+id/partNumberRevisionSpinner"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:clickable="true" />

This worked for me, now my counter loads into my navigation box without any problems.

0
source

here is the activity code

import..

public class Game extends ActionBarActivity implements AdapterView.OnItemSelectedListener {
    Spinner spin;
    TextView rembal;
    TextView bet_amount;
    TextView result;
    TextView beton;
    EditText bet;
    Button okgen;
    String options[]={"ODD NUMBER","EVEN NUMBER","PRIME NUMBER","MULTIPLE OF 3","EXACT NUMBER" };
    @Override
    protected void onCreate(Bundle savedInstanceState) {setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);

        spin=(Spinner)findViewById(R.id.spinner);
        rembal=(TextView)findViewById(R.id.textView8);
        bet_amount=(TextView)findViewById(R.id.textView9);
        beton=(TextView)findViewById(R.id.textView10);
        result=(TextView)findViewById(R.id.textView11);
        bet=(EditText)findViewById(R.id.editText2);
        okgen=(Button)findViewById(R.id.button4);

        ArrayAdapter<String> adapter_option=new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,options);
        adapter_option.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spin.setAdapter(adapter_option);
        spin.setOnItemSelectedListener(this);
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_game);
        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment())
                    .commit();
        }
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_game, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        spin.setSelection(position);
    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {
        spin.setSelection(0);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {

        public PlaceholderFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_game, container, false);
            return rootView;
        }
    }
}
-1
source

More articles:


All Articles