简单的切换页面（类似于微信）

//在App.js中实现
import React from 'react';
import { StyleSheet, Text, View } from 'react-native';
import {
  StackNavigator,
  TabNavigator,
  TabBarBottom,
} from 'react-navigation';

const MainView = TabNavigator({
  MessageView:{screen:MessageView},
  FriendView:{screen: FriendView},
  MyView:{screen:MyView},
  SetView:{screen:SetView},
},{
  tabBarComponent:TabBarBottom,
  tabBarPosition:'bottom',
  swipeEnabled:false,
  tabBarOptions:{
    // showLabel:false,
    style:{
      height:70,
    }
  }
});


//在你需要切换的页面实现

import React, { Component } from 'react';
import {
  View,
  Text,
  StyleSheet,
  Button,
  Image,
  Dimensions,
  FlatList,
} from 'react-native';

export default class FriendView extends Component {
  static navigationOptions={
    title:'朋友',
    headerLeft:null,
    headerTitleStyle:{
        alignSelf:'center',
    },
    tabBarIcon:({ focused, tintColor})=>{
      if(focused==true){
        return(
          <Image
            style={{width:40,height:40}}
            source={require('../assets/images/icon2.png')}
          />
        )
      }else {
        return(
          <Image
            style={{width:35,height:35}}
            source={require('../assets/images/icon3.png')}
          />
        )
      }
    }
  }