<ListView
          dataSource={this.state.dataSource}
          renderSeparator={this.ListViewItemSeparator}
          renderRow={rowData => ( <Text> {rowData} </Text> )}
          ref="ListView_Reference"
        />

GoTo_top_function = () => {
  this.refs.ListView_Reference.scrollTo({ animated: true }, 0);
};

GoTo_bottom_function = () => {
  this.refs.ListView_Reference.scrollToEnd({ animated: true });
};