此组件相当于PC的单选下拉框，但更加炫，适应手机的触摸交互形式。

parent{
  flex:1;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background-color: #e9ea00;
}
title{
  margin-top: 10;
  height: 40;
}
text{
  font-size: 18;
  color:#660099;
}

 主程序如下：

/**
 *  picker 司徒正美
 */
'use strict';


var React = require('react-native');

var styles = require("./style")

var {
  PickerIOS,
  Text,
  View,
  AppRegistry,
  Dimensions
} = React;

var PickerItemIOS = PickerIOS.Item;

var array = [
{label: "苹果",value:"apple"},
{label:"梨",value:"pear"},
{label:"香蕉",value:"banana"},
{label:"桃", value:"peach"},
{label:"波萝", value:"pineapple"},
{label:"葡萄", value:"grape"},
]


var PickerExample = React.createClass({
  getInitialState: function() {
    return {
      selected: "pear"
    };
  },
  render: function() {

    return (
      <View style={styles.parent}>
        <Text style={styles.tilte}>选择你喜欢的水果:</Text>
        <PickerIOS
          style={{width:Dimensions.get('window').width}}
          selectedValue={this.state.selected}
          onValueChange={(value) => this.setState({selected: value})}>
          {array.map((obj) => (
            <PickerItemIOS
              key={obj.value+obj.label}
              value={obj.value}
              label={obj.label}
            />
          ))}
        </PickerIOS>
        <Text style={styles.text}>你已经选择：{this.state.selected}</Text>
      </View>
    );
  },
});

AppRegistry.registerComponent('AwesomeProject', () => PickerExample);

这里用到一个Dimensions模块，用于获取手机屏幕的宽