Question

I have placed the following code in the main activity in the onCreate method

public class MyTest extends Activity implements OnClickListener{

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
 //... some other code here to init the layout
    Button btn1 = (Button)findViewById(R.id.button1);
    Button btn2 = (Button)findViewById(R.id.button2);
    btn1.setOnClickListener(this);
    btn2.setOnClickListener(this);
}

And have placed the following code outside the class MyTest

@Override
public void onClick(View v) {
    switch(v.getId()){
        case R.id.button1:
            break;
        case R.id.button2:
            break;
    }
}

When running the application it crashes. Please can someone help me

Answer 1

Actually you forgot setContentView(R.layout.<main_xml>); in onCreate() of Activity before defining Buttons.

Something like,

protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.<main_xml>); // This line is necessary
 .
 .
 .

Update:

Also You have to put

@Override
public void onClick(View v) {
    switch(v.getId()){
        case R.id.button1:
            break;
        case R.id.button2:
            break;
    }
}

at outside of onCreate() method as part of your MyTest Activity Class. Not the outside of MyTest Activity Class.