title: How to determine if an input in EditText is an integer?
body: <p>Hi I'm a newbie in Android Programming. </p>
  
  <p>I'm trying to build an activity which includes an <code>edittext</code> field and a <code>button</code>. When user type in an integer, the button will lead them to the next activity. However I do not if there's a way to check the type of user's input. </p>
  
  <p>Anyone can help me? Thank you very much！</p>