Question

   package woot.wat.wen;

import android.app.Activity;
import android.os.Bundle;
import android.text.Layout;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnKeyListener;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.view.ViewGroup.MarginLayoutParams;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;

public class HmmActivity extends Activity implements OnKeyListener  {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        //RelativeLayout Relay=(RelativeLayout) getResources().getLayout(R.layout.main);
        ViewGroup group = (ViewGroup) findViewById(R.id.relativeLayout1);
        TextView tv=(TextView) findViewById(R.id.tv1);
        MarginLayoutParams mapara = new MarginLayoutParams(tv.getLayoutParams());
        mapara.setMargins(225, 260, 120, 120);


        LayoutParams params=new RelativeLayout.LayoutParams(mapara);
        tv.setLayoutParams(params);
        group.setFocusable(true);
        group.setOnKeyListener(this);

        int children = group.getChildCount();
        for (int i = 0; i < children; i++) {

            View child = group.getChildAt(i);
            child.setFocusable(true);
            child.setOnKeyListener(this);


            }



        //tv.setOnKeyListener(this);


    }


    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        // TODO Auto-generated method stub
        if (keyCode == KeyEvent.KEYCODE_BACK &&  event.getRepeatCount() == 0) {
              //    back=true;
                    // do something on back.
            Toast.makeText(this, "Back key pressed", Toast.LENGTH_SHORT);




            System.out.println("WTF");


                    return true;
                }



        else    

            return super.onKeyDown(keyCode, event);
    }


    public boolean onKey(View v, int keyCode, KeyEvent event) {
                if (keyCode == KeyEvent.KEYCODE_BACK /*&& event.getRepeatCount() == 0*/) {
              //    back=true;
                    // do something on back.
                    Log.d("backk", "goingoin backback");






                    return true;
                }

                else
                // TODO Auto-generated method stub
                return super.onKeyDown(keyCode, event);
                //return false;
            }






    }

As you can see in the code i am trying to do something when the back key is pressed but the onkey codes never seem to be used.
The program never seems to go into onKey method whenever back is pressed,both in emulator and the device.Any idea what i am doing wrong..?

I’ve put the updated code.

Ok I’ve created a new clean project.Heres the code

package you.packag.namespac;

import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.widget.Toast;

public class BlActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }

@Override
public boolean onKeyDown(int keyCode, KeyEvent event){
    if(keyCode==KeyEvent.KEYCODE_BACK){
        Toast.makeText(this, "Back key pressed", Toast.LENGTH_SHORT);
        return true; //that is important
    }else 
    return super.onKeyDown(keyCode, event);
}
}

Still the same problem.The toast is not displayed.The program flow/control goes to both the return true and return super statements each time back is pressed.Dont really see how that should be happening.Really driving me crazy.Must be something small I am doing wrong.Please help.

Answer 1

Try to

@Override
public boolean onKeyDown(int keyCode, KeyEvent event){
    if(keyCode==KeyEvent.KEYCODE_BACK){
        Toast.makeText(this, "Back key pressed", Toast.LENGTH_SHORT).show();
        return true; //that is important
    }else 
    return super.onKeyDown(keyCode, event);
}

Or in your code:

1) Put @Override before your onKey method

2) change return false to return super.onKey(keyCode, event)

Also – it’s not neccesary to implement OnKeyListener