content: 'use strict';
  import React, { Component } from 'react';
  import {
    StyleSheet,
    Text,
    View,
    PixelRatio,
    TouchableOpacity,
    Image,
    Alert,
    Dimensions,
    Platform
  } from 'react-native';
  
  import ImagePicker from 'react-native-image-picker';
  let Width = Dimensions.get('window').width;
  export default class toupiao extends Component {
    constructor(props) {
      super(props);
      this.state = {
        photo: null,
      };
  }
    selectPhotoTapped() {
      const options = {
        quality: 0.8,
        maxWidth: 500,
        maxHeight: 500,
        storageOptions: {
          skipBackup: true
        }
      };
  
      ImagePicker.showImagePicker(options, (response) => {
        console.log('Response = ', response);
  
        if (response.didCancel) {
          console.log('User cancelled photo picker');
        }
        else if (response.error) {
          console.log('ImagePicker Error: ', response.error);
        }
        else if (response.customButton) {
          console.log('User tapped custom button: ', response.customButton);
        }
        else {
          var source;
  
  	        // You can display the image using either:
          //source = {uri: 'data:image/jpeg;base64,' + response.data, isStatic: true};
  
          //Or:
          if (Platform.OS === 'android') {
            source = {uri: response.uri, isStatic: true};
          } else {
            source = {uri: response.uri.replace('file://', ''), isStatic: true};
          }
  
          this.setState({
            photo: source
          });
        }
      });
    }
  
  
    _addUser(){
      var fileData = this.state.photo;
  	if(!fileData){
  		Alert.alert('提示','请点击上传图片');
  		return ;
  	}
  
    }
  
    render() {
      return (
        <View style={styles.container}>
          <TouchableOpacity onPress={this.selectPhotoTapped.bind(this)}>
            <View style={[styles.avatar, styles.avatarContainer, {marginBottom: 20}]}>
            { this.state.photo === null ? <Text>点击上传图片</Text> :
              <Image style={styles.avatar} source={this.state.photo} />
            }
            </View>
          </TouchableOpacity>
  
          <View style={{marginTop:30, alignItems:'center', justifyContent:'center'}}>
             <TouchableOpacity onPress={this._addUser.bind(this)}>
               <View style={styles.btn}>
                 <Text style={{fontSize:20, color: 'black'}}>提交</Text>
               </View>
             </TouchableOpacity>
         </View>
  
        </View>
      );
    }
  
  }
  
  const styles = StyleSheet.create({
    container: {
      flex: 1,
      justifyContent: 'center',
      alignItems: 'center',
      backgroundColor: '#F5FCFF'
    },
    avatarContainer: {
      borderColor: '#9B9B9B',
      borderWidth: 1 / PixelRatio.get(),
      justifyContent: 'center',
      alignItems: 'center'
    },
    btn:{
      borderColor:'#ddd',
      height:35,
      width:Width-30,
      borderRadius:5,
      borderWidth:2,
      marginLeft:13,
      marginRight:13,
      backgroundColor:'blue',
      alignItems:'center',
      justifyContent:'center'
    },
    avatar: {
  
      width: 250,
      height: 250
    }
  });
  