import DropdownMenu from 'react-native-dropdown-menu';  export default class Demo extends Component {    constructor(props) {     super(props);     this.state = {       text: ''     };   }      render() {     var data = [["C", "Java", "JavaScript", "PHP"], ["Python", "Ruby"], ["Swift", "Objective-C"]];     return (       <View style={{flex: 1}}>         <View style={{height: 64}} />         <DropdownMenu           style={{flex: 1}}           bgColor={'white'}           tintColor={'#666666'}           activityTintColor={'green'}           // arrowImg={}                 // checkImage={}              // optionTextStyle={{color: '#333333'}}           // titleStyle={{color: '#333333'}}            // maxHeight={300}            handler={(selection, row) => this.setState({text: data[selection][row]})}           data={data}         >            <View style={{flex: 1}}>             <Text>               {this.state.text} is the best language in the world             </Text>           </View>          </DropdownMenu>       </View>     );   }    }