title: AlertDialog in View class?
body: <p>I created the class extending View. Now I want to show AlertDialog when user do something.
  How can I do that?</p>
  
  <pre><code>AlertDialog alertDialog = new AlertDialog.Builder(this).create();
  </code></pre>
  
  <p>This code isn't working, because "this" variable should be an Activity, but "this" in my class is "Drawable".</p>