Bind Picker to list of Picker.Item in React Native

You should probably set up your initial state as the empty array, then call your service on componentWillMount or componentDidMount. I've set up something that works with some dummy data here, and pasted the code below.

'use strict';
var React = require('react-native');
var {
    Picker,
    Text,
    View,
      AppRegistry
} = React;

var PickerItem = Picker.Item;

var SampleApp = React.createClass({
    getInitialState() {
        return {
            services: ['a', 'b', 'c', 'd', 'e'],
            selectedService: 'a'
        }
    },

    componentDidMount() {
        setTimeout(() =>  { 
         this.setState({
          services: [ 'one', 'two', 'three', 'four', 'five' ]
         }) 
        }, 3000)
    },

    render() {
        let serviceItems = this.state.services.map( (s, i) => {
            return <Picker.Item key={i} value={s} label={s} />
        });

        return (
            <View>
                <Text>Pick a service</Text>
                <Picker
                    selectedValue={this.state.selectedService}
                    onValueChange={ (service) => ( this.setState({selectedService:service}) ) } >

                    {serviceItems}

                </Picker>
            </View>
        );
    }
});


AppRegistry.registerComponent('SampleApp', () => SampleApp);

IMPORTANT: if you try to iterate an array of numbers with map then don't forget that label property of Picker.Item should be converted to string:

const pickerItems = [1,2,3].map(i => (
      <Picker.Item label={i.toString()} value={i} />
));