Change textView text in onCreate function
<p>Can anyone tell me why am i getting error message <code>java.lang.NullPointerException</code> in following code??</p>

<pre><code>package firstApp.hangman;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.widget.TextView;

public class HangmenActivity extends Activity 
{
    private String word_to_guess;

    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        this.set_random_word(); 
        TextView wordToGuess = (TextView) findViewById(R.id.word_to_guess);
        try
        {
            wordToGuess.setText(this.word_to_guess);
        }
        catch(Exception  e)
        {
            AlertDialog alertDialog = new AlertDialog.Builder(this).create();
            alertDialog.setTitle("error");
            alertDialog.setMessage(e.toString());
            alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
               public void onClick(DialogInterface dialog, int which) {
                  // here you can add functions
               }
            });
            alertDialog.setIcon(R.drawable.icon);
            alertDialog.show();
        }

        setContentView(R.layout.main);
    }

    private void set_random_word()
    {
        this.word_to_guess = "abcdef";
    }    

}
</code></pre>
