title: Unable to set text in a Text View
body: <p>I have a strange problem using Android Studio. I can't set the text of a TextView (tAx), the reference isn't a 'null pointer', and I haven't error or exception, just I don't see the text. </p>
  
  <p>My main class:</p>
  
  <pre><code> @Override
  public void onCreate(Bundle savedInstanceState) {
      setContentView(R.layout.main);
      super.onCreate(savedInstanceState);
  
      getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE,   R.layout.custom_title);
  
  
      tAx = (TextView) findViewById(R.id.Ax);
      tAx.setText("prova");
      // Set up the custom title
      mTitle = (TextView) findViewById(R.id.title_left_text);
    //  mTitle.setText(R.string.app_name);
      mTitle = (TextView) findViewById(R.id.title_right_text);
  
      // Get local Bluetooth adapter
      mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
  
      // If the adapter is null, then Bluetooth is not supported
      if (mBluetoothAdapter == null) {
          Toast.makeText(this, "Bluetooth is not available",         Toast.LENGTH_LONG).show();
          finish();
          return;
      }
  }
  </code></pre>
  
  <p>XML Main :</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:weightSum="1"&gt;
  
  &lt;TextView android:id="@+id/Ax"
      android:layout_width="198dp"
      android:layout_height="38dp"
      android:textSize="20dp"
      android:visibility="visible"
      android:background="#ffffffff"
      android:textColor="#fff"
   /&gt;
  
  
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>Thank's you!</p>
  
  <p>Update:</p>
  
  <p>Thank's you! So now I can set the text but only one time(the first time)! In another class, I try to set the text by reference (using tax reference that is static and public), but them doesn't change, but remains the first, and Android Studio print on the console the error:</p>
  
  <blockquote>
    <p>Only the original thread that created a view hierarchy can touch its
    views</p>
  </blockquote>
  
  <p><code>RemoteBluetooth.tAx.setText(String.valueOf(Ax));</code></p>