title: Fixed button over a scrollview
body: <p>I'm currently trying to display a button on the bottom right corner of my screen, over a scrollview, but it doesn't work. The button moves when I scroll my view. I tried to insert the button first, but the scrollview is over it. </p>
  
  <pre><code>class HomePage extends Component {
    loadUserItems() {
      this.props.loadUserItems();
    }
    constructor(props) {
      super(props);
      this.loadUserItems();
    }
    render() {
      return (
        &lt;Container&gt;
          &lt;Content&gt;
          &lt;Header /&gt;
            &lt;View&gt;
              &lt;ItemSquareDisplay
                items={this.props.items &amp;&amp; this.props.items.length &gt; 0
                  ? this.props.items
                  : ''} /&gt;
            &lt;/View&gt;
            &lt;Button style={styles.buttonStyle}&gt;
              &lt;Text style={styles.buttonTextStyle}&gt;+&lt;/Text&gt;
            &lt;/Button&gt;
          &lt;/Content&gt;
        &lt;/Container&gt;
      );
    }
  }
  // CONNECTE LES PROPS DE CETTE CLASSE AUX STATES DE REDUX
  const mapStateToProps = state =&gt; {
    return {
      items: state.items.items,
    };
  };
  // PERMET A CETTE CLASSE DE LINKER LES PROPS AUX ACTIONS DE REDUX
  export default connect(mapStateToProps, {loadUserItems}) ( HomePage );
  const styles = {
    headerViewStyle : {
      alignItems: 'center',
      backgroundColor: '#cc003d',
      height: 90
    },
    headerImageStyle : {
      height: 80,
      width: 250,
      resizeMode: 'contain',
      marginTop: 7,
    },
    buttonStyle : {
      backgroundColor: '#fc454e',
      width: 66,
      height: 66,
      borderRadius: 33,
      justifyContent: 'center',
      alignItems:'center',
      position: 'absolute',
      bottom: 20,
      right: 20
    },
    buttonTextStyle : {
      color:'white',
      fontSize: 45,
      marginBottom: 6
    }
  }
  </code></pre>
  
  <p>I tried 'fixed' position, but it isn't supported by react-native. 
  I want the button to be over my items. 
  <a href="https://i.stack.imgur.com/KGvUt.png" rel="noreferrer"><img src="https://i.stack.imgur.com/KGvUt.png" alt="Output"></a></p>
  
  <p>But I don't want it to move when I scroll the view. </p>