title: Error when parsing string to int
body: <p>Im generating 2 random values and in EditText you need to enter a result of adding this 2 values and when im tring to parse that what i get from edittext it crash my application</p>
  
  <pre><code>public class Main2Activity extends AppCompatActivity {
  
  public int wynik;
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main2);
      Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
      setSupportActionBar(toolbar);
  
      setContentView(R.layout.activity_main2);
      TextView text = (TextView) findViewById(R.id.txtv);
  
      Random r = new Random();
      int i1 = (r.nextInt(100 - 1) + 1);
      int i2 = (r.nextInt(100 - 1) + 1);
      text.setText(i1 +" + " + i2 + " = ");
      wynik =i1+i2;
  };
      public void backtomain(View view)
      {
          EditText editText = (EditText) findViewById(R.id.edittext);
          String etstring =editText.getText().toString();
          Integer etint = Integer.parseInt(etstring); &lt;---------------- CRASH CUZ OF THIS LINE
  
          //if(etint==wynik)
          //{
              Intent intent = new Intent(this, AalarmActivity.class);
              intent.putExtra("toggleBtn", true);
              startActivity(intent);
              finish();
          //}
          //else
          //{
          //    Toast.makeText(this, "Error ",
          //            Toast.LENGTH_LONG).show();
          //}
      }
  }
  </code></pre>
  
  <p>Commented lines are not finished first need to repair that parsing part.</p>