Question

my app crashes with this code.. it doesnt even start up.. any ideas guys thanks
my app crashes with this code.. it doesnt even start up.. any ideas guys thanks

package com.about.bysk;


import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.Spinner;
import android.widget.Toast;

public abstract class AboutActivity extends Activity implements
        OnItemSelectedListener {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Spinner spinner = (Spinner) findViewById(R.id.spin);
        spinner.setOnItemSelectedListener(new OnItemSelectedListener() {

            public void onItemSelected(AdapterView<?> arg0, View arg1,
                    int arg2, long arg3) {
                Toast.makeText(null, "a", 5);

            }

            public void onNothingSelected(AdapterView<?> arg0) {
                // TODO Auto-generated method stub

            }
        });
    }
}

this makes my app crash. please help..

Answer 1

You have to set Listener for your spinner and your class must implement OnItemSelectedListener

public class YourClass extends Activity implements OnItemSelectedListener { ... }

Then you must set Listener for your spinner:

spinner.setOnItemSelectedListener(this);

Or you can use it like anonymous class

spinner.setOnItemSelectedListener(new OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) { ... }

    @Override
    public void onNothingSelected(AdapterView<?> parentView) { ... }
});

Note: If you want to show Toast, you must call show() method.