text: import React, { Component } from 'react'
  import {
    Platform,
    StyleSheet,
    View,
    Text,
    Button,
    Picker,
    CheckBox,
    // ProgressViewIOS,
    Switch,
    TextInput,
    TouchableHighlight,
    TouchableOpacity,
    TouchableWithoutFeedback,
    ActivityIndicator,
    StatusBar,
    Alert,
    Image,
    ListView,
    AppRegistry,
  } from 'react-native'
  
  const base64Icon =
    'data:image/png;base64,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'
  // import { StackNavigator } from 'react-navigation';
  const instructions = Platform.select({
    ios: 'Press Cmd+R to reload,\n' + 'Cmd+D or shake for dev menu',
    android:
      'Double tap R on your keyboard to reload,\n' +
      'Shake or press menu button for dev menu',
    web: 'Cmd + R reload,\n' + 'Cmd + F12 for dev menu',
  })
  const onPressLearnMore = () => {
    Alert.alert('Button has been pressed!')
  }
  const ComplexButtonDemo = () => (
    <View style={styles.container}>
      <Text style={styles.welcome}>Welcome to React Native!</Text>
      <Text style={styles.instructions}>To get started, edit App.js</Text>
      <Text style={styles.instructions}>{instructions}</Text>
      <Text style={styles.welcome}>组件使用例子</Text>
  
      <Text>
        复选框：<CheckBox
          color="#F5FCFF"
          value
          style={{ height: 16, width: 16 }}
        />
        <CheckBox
          disabled
          color="#F5FCFF"
          value
          style={{ height: 16, width: 16 }}
        />
      </Text>
      {/* <Text>ProgressBar:</Text> */}
      {/* <ProgressBar/> */}
      <Text>Switch:</Text>
      <Switch
        style={{ height: 26 }}
        value
        activeTrackColor="#939393"
        activeThumbColor="#FAFAFA"
      />
      <Text>TextInput:</Text>
      <TextInput value="abc" editable style={{ height: 26, width: 100 }} />
      <Text>ActivityIndicator:</Text>
      <ActivityIndicator />
      <ActivityIndicator animating />
      <TouchableHighlight onPress={() => {}}>
        <Text>TouchableHighlight:</Text>
      </TouchableHighlight>
      <TouchableOpacity onPress={() => {}}>
        <Text>TouchableOpacity:</Text>
      </TouchableOpacity>
      <TouchableWithoutFeedback onPress={() => {}}>
        <View>
          <Text>TouchableWithoutFeedback:</Text>
        </View>
      </TouchableWithoutFeedback>
    </View>
  )
  export default ComplexButtonDemo
  
  const styles = StyleSheet.create({
    container: {
      flex: 1,
      justifyContent: 'center',
      alignItems: 'center',
      backgroundColor: '#F5FCFF',
    },
    base64: {
      flex: 1,
      height: 50,
      width: 200,
      resizeMode: 'contain',
    },
    welcome: {
      fontSize: 20,
      textAlign: 'center',
      margin: 10,
    },
    instructions: {
      textAlign: 'center',
      color: '#333333',
      marginBottom: 5,
    },
  })
  
  // import React, { Component } from 'react';
  // import {
  //   Platform,
  //   StyleSheet,
  //   View,
  //   Text,
  //   Button,
  //   AppRegistry,
  // } from 'react-native';
  // import { StackNavigator } from 'react-navigation';
  // // const instructions = Platform.select({
  // //   ios: 'Press Cmd+R to reload,\n' +
  // //     'Cmd+D or shake for dev menu',
  // //   android: 'Double tap R on your keyboard to reload,\n' +
  // //     'Shake or press menu button for dev menu',
  // //     web: 'Cmd + R reload,\n' +
  // //     'Cmd + F12 for dev menu',
  // // });
  
  // // const ComplexButtonDemo = () => (
  // //    <View style={styles.container}>
  // //         <Text style={styles.welcome}>
  // //           Welcome to React Native!
  // //         </Text>
  // //         <Text style={styles.instructions}>
  // //           To get started, edit App.js
  // //         </Text>
  // //         <Text style={styles.instructions}>
  // //           {instructions}
  // //         </Text>
  // //       </View>
  // // );
  // // export default ComplexButtonDemo
  
  // // const styles = StyleSheet.create({
  // //   container: {
  // //     flex: 1,
  // //     justifyContent: 'center',
  // //     alignItems: 'center',
  // //     backgroundColor: '#F5FCFF',
  // //   },
  // //   welcome: {
  // //     fontSize: 20,
  // //     textAlign: 'center',
  // //     margin: 10,
  // //   },
  // //   instructions: {
  // //     textAlign: 'center',
  // //     color: '#333333',
  // //     marginBottom: 5,
  // //   },
  // // });
  
  // // import MyScene from './MyScene';
  // const HomeScreen = () => (
  //   <View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}>
  //     <Text>Home Screen</Text>
  
  //   </View>
  // );
  
  // const DetailsScreen = () => (
  //   <View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}>
  //     <Text>Details Screen</Text>
  //   </View>
  // );
  
  // const RootNavigator = StackNavigator({
  //  Home: {
  //     screen: HomeScreen,
  
  //   },
  //   Details: {
  //     screen: DetailsScreen,
  
  //   },
  // });
  
  // export default RootNavigator;
  