title: How to make callback from AsyncTask to fragment Activity?
body: <p>I have requests to web service implemented using AsyncTask. Normally callback to Activity i do using interface:</p>
  
  <pre><code>public interface AsyncTaskComplete&lt;T&gt; {
  
      public void onTaskComplete(T result);
      public void onTaskFailed(T result);
  
  }
  </code></pre>
  
  <p>In AsyncTask:</p>
  
  <pre><code>private AsyncTaskComplete&lt;String&gt; callback;
  
  public AsyncTaskAbout(AsyncTaskComplete&lt;String&gt; cb) {
      this.callback = cb;
  }
  
  protected void onPostExecute(String result) {
      if(result ==  null){
          callback.onTaskFailed(result);
      }else{
          callback.onTaskComplete(result);
      }
  
  }
  </code></pre>
  
  <p>But if i want to give callback FragmentActivity compiler suggest me to change AsyncTask constructor to:</p>
  
  <pre><code>public AsyncTaskAbout(FragmentActivity faActivity) {
      this.callback = (AsyncTaskComplete&lt;String&gt;) faActivity;
  }
  </code></pre>
  
  <p>Where is warning:</p>
  
  <pre><code>Type safety: Unchecked cast from FragmentActivity to AsyncTaskComplete&lt;String&gt;
  </code></pre>
  
  <p>So what i need to change ?</p>
  
  <p>Or how to make callback in this case ?</p>
  
  <p>Thanks.</p>