Setonclicklistener Is Causing "runtimeexception: Unable To Start" - Nullpointerexception

I got an error, and I can't understand what's causing it. This is the snippet of code that generates the error: public class RssReader extends Activity { private Button button1; @O

Solution 1:

You have to call setContentView(R.layout.rss_reader); before registering your OnClickListeners.

package com.cris96.rssreader;

import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.Button;

publicclassRssReaderextendsActivity {
    private Button button1;

    @OverridepublicvoidonCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.rss_reader);

        button1 = (Button) findViewById(R.id.b1);
        button1.setOnClickListener(newView.OnClickListener() {

            publicvoidonClick(View v) {
                System.out.println("test");

            }
        });

    }

}

Solution 2:

You need to do it this way:

publicvoidonCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.rss_reader);
button1 = (Button)findViewById(R.id.b1);
button1.setOnClickListener(newView.OnClickListener() {

    publicvoidonClick(View v) {
        System.out.println("test");
    }
  });
}

You can't set the find the view before set the layout as a content of the Activity. This is the reason that findViewById returns null.