React Native(四)——顶部以及底部导航栏实现方式

效果图：

一步一步慢慢来：

其实刚入手做app的时候，就应该做出简单的顶部以及底部导航栏。无奈又在忙其他事情，导致这些现在才整理出来。

1.顶部导航栏：react-native-scrollable-tab-view；文档地址：https://github.com/skv-headless/react-native-scrollable-tab-view

2.底部导航栏：react-navigation中的TabNavigator；文档地址：https://reactnavigation.org/docs/navigators/tab

3.一直想让index.android.js的代码简洁一些，苦思不得其解，直到现在才找到了一点“路径”，看这版的源代码：

index.android.js：

/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 * @flow
 */

import React, { Component } from \'react\';
import {
  AppRegistry,
  StyleSheet,
  Text,
  View,
  Image
} from \'react-native\';

//顶部导航栏
import TopTabBar from \'./Views/TopTabBar\';
//底部导航栏
import BottomTabBar from \'./Views/BottomTabBar\';


export default class ywg extends Component {
  render() {
    return (
      <View style={{flex:1}}>
        <TopTabBar/>
        <BottomTabBar/>
      </View>    
    );
  }
}

AppRegistry.registerComponent(\'ywg\', () => ywg);

怎样？够简单吧……对了，这样的代码看起来才比较“优雅”（容忍zheng小叶正儿八经的胡说八道哦~）而主要的代码就在

//顶部导航栏
import TopTabBar from \'./Views/TopTabBar\';
//底部导航栏
import BottomTabBar from \'./Views/BottomTabBar\';

这两个红色的文件中。

【重点注意】将两个Component同时使用的时候，一定要在最外层的View上定义样式，否则任你怎样摆弄，它们总是不会展现“庐山真面目”，具体的文档在：http://reactnative.cn/docs/0.46/layout-props.html

这是项目文件路径。

BottomTabBar.js:

/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 * @flow
 */

import React, { Component } from \'react\';
import {
  AppRegistry,
  StyleSheet,
  Text,
  View,
  Image
} from \'react-native\';

//底部导航栏
import { TabNavigator } from "react-navigation";

class Home extends React.Component {
  static navigationOptions = {
      tabBarLabel: \'热点\',
      tabBarIcon: ({ focused, tintColor }) => (
          <Image
              source={focused ? require(\'../Images/hot_hover.png\') : require(\'../Images/hot.png\')}
              style={{ width: 26, height: 26, tintColor: tintColor }}
          />
      )
  };
  render() {
      return (
          <View style={styles.container}>
              <Text>这是热点</Text>
          </View>
      );
  }
}   class Circle extends React.Component {
  static navigationOptions = {
      tabBarLabel: \'圈子\',
      tabBarIcon: ({ focused, tintColor }) => (
          <Image
              source={focused ? require(\'../Images/coterie_hover.png\') : require(\'../Images/coterie.png\')}
              style={{ width: 26, height: 26, tintColor: tintColor }}
          />
      )
  };
  render() {
      return (
          <View style={styles.container}>
              <Text>这是圈子内容</Text>
          </View>
      );
  }
}   class Tools extends React.Component {
  static navigationOptions = {
      tabBarLabel: \'工具\',
      tabBarIcon: ({ focused, tintColor }) => (
          <Image
              source={focused ? require(\'../Images/tool.png\') : require(\'../Images/tool.png\')}
              style={{ width: 26, height: 26, tintColor: tintColor }}
          />
      )
  };
  render() {
      return (
          <View style={styles.container}>
              <Text>这是工具内容</Text>
          </View>
      );
  }
}
class Mypage extends React.Component {
    static navigationOptions = {
      tabBarLabel: \'我的\',
      tabBarIcon: ({ focused, tintColor }) => (
        <Image
          source={focused ? require(\'../Images/my_hover.png\') : require(\'../Images/my.png\')}
          style={{ width: 26, height: 26, tintColor: tintColor }}
        />
      )
    };
    render() {
      return (
        <View style={styles.container}>
          <Text>这是我的内容</Text>
        </View>
      );
    }
}

const BottomTabBar = TabNavigator(
  {
    Home: {
      screen: Home,
    },
    Circle: {
      screen: Circle,
    },
    Tools: {
      screen: Tools,
    },
    Mypage: {
      screen: Mypage,
    },
  },
  {
    tabBarOptions: {
      activeTintColor: \'#4BC1D2\',
      inactiveTintColor: \'#000\',
      showIcon: true,
      showLabel: true,
      upperCaseLabel: false,
      pressColor: \'#823453\',
      pressOpacity: 0.8,
      style: {
        backgroundColor: \'#fff\',
        paddingBottom: 0,
        borderTopWidth: 0.5,
        borderTopColor: \'#ccc\',
      },
      labelStyle: {
        fontSize: 12,
        margin: 1
      },
      indicatorStyle: { height: 0 }, //android 中TabBar下面会显示一条线，高度设为 0 后就不显示线了
    },
    tabBarPosition: \'bottom\',
    swipeEnabled: false,
    animationEnabled: false,
    lazy: true,
    backBehavior: \'none\',
  });

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: \'center\',
    alignItems: \'center\',
    backgroundColor: \'#fff\',
  }
});

module.exports = BottomTabBar;

TopTabBar.js:

/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 * @flow
 */

import React, { Component } from \'react\';
import {
  AppRegistry,
  StyleSheet,
  Text,
  View,
  Image
} from \'react-native\';
import HomePage from \'../Views/HomePage\';
import PricePage from \'../Views/PricePage\';
import InventoryPage from \'../Views/InventoryPage\';

//顶部导航
var ScrollableTabView = require(\'react-native-scrollable-tab-view\');


export default class TopTabBar extends Component {
  render() {
    return (
      <ScrollableTabView 
       tabBarUnderlineStyle={{backgroundColor:\'#fff\'}}
      >
        <HomePage tabLabel="首页" />
        <PricePage tabLabel="成交价" />
        <InventoryPage tabLabel="库存" />
      </ScrollableTabView>
    );
  }
}
module.exports = TopTabBar;

而关于这些的详细介绍可以参考这里（老大的小结）：http://www.cnblogs.com/vipstone/p/7516115.html?utm_source=tuicool&utm_medium=referral；

美中不足：

怎样才能实现顶部栏、底部栏控制各自部分功能呢？留下来的~~~

PS:尴尬的事情猝不及防的发生了……

一直想不明白，顶部导航栏跟底部导航栏同时存在的情况下，怎样控制各自的功能呢？于是再请教完做手机开发的同事后才恍然大悟，原来自己想的顶部导航栏根本不是顶部导航栏，简言之就是自己把布局搞错了！明明只是有底部导航栏，而所谓的“顶部导航栏”也只是底部导航栏中的第一小部分里面嵌套着一个轮播组件，才会给人以错觉，啊啊啊……事实真相居然是这样的~