Application crashes on button click

Question

Have problem that when I press button application crashes. Crash text package com.leftas.vidurkioskaiciavimas;

 24367-24367/com.leftas.vidurkioskaiciavimas E/An         


        

Answer 1

try this

  mUserOutput = (TextView) findViewById(R.id.textView2);
  mUserInput = (TextView) findViewById(R.id.textView);

You have already Declared textview's as class member. So initialize them as above.

This

  TextView mUserOutput = (TextView) findViewById(R.id.textView2); 
  // makes mUserOutput local 

Answer 2

findviewbyid and mUserOutput.setOnClickListener(this); required .

also implement onLCicklistener like: public class MainActivity extends Activity implements OnClickListener{