<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical" >
  <AutoCompleteTextView
    android:id="@+id/tv"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" />
</LinearLayout>

protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 
 mTextView = (AutoCompleteTextView)findViewById(R.id.tv);
 
 ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line,autoStr);
 mTextView.setAdapter(adapter);
}

mTextView.setTokenizer(new MultiAutoCompleteTextView.CommaTokenizer());