Question

我想在主屏幕的底部添加标签，但是我不知道该怎么做。我想要两个标签，例如“地图”（对于我的主页）和“设置”。我不知道如何创建它，我试图在其中添加一些代码，但是它不起作用。您对我在做什么错有想法吗？

我需要在其中添加这些代码吗？

class HomeScreen extends React.Component {
  render() {
    return (

class SettingsScreen extends React.Component {
  render() {
    return (

我也尝试在底部添加此代码：

const TabNavigator = createBottomTabNavigator({
  MAP: { screen: HomeScreen },
  SETTINGS: { screen: SettingsScreen },
});

export default createAppContainer(TabNavigator);

这是我的代码：


import React, { Component } from 'react';
import { StyleSheet, Text, View, Animated, Image, Dimensions } from "react-native";
import { Components, MapView } from 'expo';


const Images = [
  { uri: "https://images.unsplash.com/photo-1555706655-6dd427c11735?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=750&q=80" },
  { uri: "https://images.unsplash.com/photo-1555706741-8f39aa887cf7?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=750&q=80" },
  { uri: "https://images.unsplash.com/photo-1555706741-fade7dd756a9?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=750&q=80" },
  { uri: "https://images.unsplash.com/photo-1555706742-67a1170e528d?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=750&q=80" }
]

const { width, height } = Dimensions.get("window");

const CARD_HEIGHT = height / 5;
const CARD_WIDTH = CARD_HEIGHT - 50;


export default class screens extends Component {
  state = {
    markers: [
      {
        coordinate: {
          latitude: 41.414494,
          longitude: 2.152695,
        },
        title: "Parc Güell",
        description: "One of the best view in Barcelona. ",
        image: Images[0],
      },
      {
        coordinate: {
          latitude: 41.403706,
          longitude: 2.173504,
        },
        title: "Sagrada Familia",
        description: "This is the second best place in Portland",
        image: Images[1],
      },
      {
        coordinate: {
          latitude: 41.395382,
          longitude: 2.161961,
        },
        title: "Casa Milà",
        description: "This is the third best place in Portland",
        image: Images[2],
      },
      {
        coordinate: {
          latitude: 41.381905,
          longitude: 2.178185,
        },
        title: "Gothic Quarter",
        description: "This is the fourth best place in Portland",
        image: Images[3],
      },
    ],
    region: {
      latitude: 41.390200,
      longitude: 2.154007,
      latitudeDelta: 0.04864195044303443,
      longitudeDelta: 0.040142817690068,
    },
  };

  componentWillMount() {
    this.index = 0;
    this.animation = new Animated.Value(0);
  }
  componentDidMount() {
    // We should detect when scrolling has stopped then animate
    // We should just debounce the event listener here
    this.animation.addListener(({ value }) => {
      let index = Math.floor(value / CARD_WIDTH + 0.3); // animate 30% away from landing on the next item
      if (index >= this.state.markers.length) {
        index = this.state.markers.length - 1;
      }
      if (index <= 0) {
        index = 0;
      }

      clearTimeout(this.regionTimeout);
      this.regionTimeout = setTimeout(() => {
        if (this.index !== index) {
          this.index = index;
          const { coordinate } = this.state.markers[index];
          this.map.animateToRegion(
            {
              ...coordinate,
              latitudeDelta: this.state.region.latitudeDelta,
              longitudeDelta: this.state.region.longitudeDelta,
            },
            350
          );
        }
      }, 10);
    });
  }

  render() {
    const interpolations = this.state.markers.map((marker, index) => {
      const inputRange = [
        (index - 1) * CARD_WIDTH,
        index * CARD_WIDTH,
        ((index + 1) * CARD_WIDTH),
      ];
      const scale = this.animation.interpolate({
        inputRange,
        outputRange: [1, 2.5, 1],
        extrapolate: "clamp",
      });
      const opacity = this.animation.interpolate({
        inputRange,
        outputRange: [0.35, 1, 0.35],
        extrapolate: "clamp",
      });
      return { scale, opacity };
    });

    return (
      <View style={styles.container}>
        <MapView
          ref={map => this.map = map}
          initialRegion={this.state.region}
          style={styles.container}
        >
          {this.state.markers.map((marker, index) => {
            const scaleStyle = {
              transform: [
                {
                  scale: interpolations[index].scale,
                },
              ],
            };
            const opacityStyle = {
              opacity: interpolations[index].opacity,
            };
            return (
              <MapView.Marker key={index} coordinate={marker.coordinate}>
                <Animated.View style={[styles.markerWrap, opacityStyle]}>
                  <Animated.View style={[styles.ring, scaleStyle]} />
                  <View style={styles.marker} />
                </Animated.View>
              </MapView.Marker>
            );
          })}
        </MapView>
        <Animated.ScrollView
          horizontal
          scrollEventThrottle={1}
          showsHorizontalScrollIndicator={false}
          snapToInterval={CARD_WIDTH}
          onScroll={Animated.event(
            [
              {
                nativeEvent: {
                  contentOffset: {
                    x: this.animation,
                  },
                },
              },
            ],
            { useNativeDriver: true }
          )}
          style={styles.scrollView}
          contentContainerStyle={styles.endPadding}
        >
          {this.state.markers.map((marker, index) => (
            <View style={styles.card} key={index}>
              <Image
                source={marker.image}
                style={styles.cardImage}
                resizeMode="cover"
              />
              <View style={styles.textContent}>
                <Text numberOfLines={1} style={styles.cardtitle}>{marker.title}</Text>
                <Text numberOfLines={1} style={styles.cardDescription}>
                  {marker.description}
                </Text>
              </View>
            </View>
          ))}
        </Animated.ScrollView>
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
  },
  scrollView: {
    position: "absolute",
    bottom: 30,
    left: 0,
    right: 0,
    paddingVertical: 10,
  },
  endPadding: {
    paddingRight: width - CARD_WIDTH,
  },
  card: {
    padding: 10,
    elevation: 2,
    backgroundColor: "#FFF",
    marginHorizontal: 10,
    shadowColor: "#000",
    shadowRadius: 5,
    shadowOpacity: 0.3,
    shadowOffset: { x: 2, y: -2 },
    height: CARD_HEIGHT,
    width: CARD_WIDTH,
    overflow: "hidden",
  },
  cardImage: {
    flex: 3,
    width: "100%",
    height: "100%",
    alignSelf: "center",
  },
  textContent: {
    flex: 1,
  },
  cardtitle: {
    fontSize: 12,
    marginTop: 5,
    fontWeight: "bold",
  },
  cardDescription: {
    fontSize: 12,
    color: "#444",
  },
  markerWrap: {
    alignItems: "center",
    justifyContent: "center",
  },
  marker: {
    width: 8,
    height: 8,
    borderRadius: 4,
    backgroundColor: "rgba(130,4,150, 0.9)",
  },
  ring: {
    width: 24,
    height: 24,
    borderRadius: 12,
    backgroundColor: "rgba(130,4,150, 0.3)",
    position: "absolute",
    borderWidth: 1,
    borderColor: "rgba(130,4,150, 0.5)",
  },
});

Answer 1

为标签导航创建一个新文件，并添加以下代码：（我将您的地图组件导入为screens）

import React from 'react';
import { Platform } from 'react-native';
import { createStackNavigator, createBottomTabNavigator } from 'react-navigation';

import TabBarIcon from '../components/TabBarIcon';
import screens from '../screens/HomeScreen';
import SettingsScreen from '../screens/SettingsScreen';

const HomeStack = createStackNavigator({
  Home: screens,
});

HomeStack.navigationOptions = {
  tabBarLabel: 'Home',
  tabBarIcon: ({ focused }) => (
    <TabBarIcon
      focused={focused}
      name={
        Platform.OS === 'ios'
          ? `ios-information-circle${focused ? '' : '-outline'}`
          : 'md-information-circle'
      }
    />
  ),
};

const SettingsStack = createStackNavigator({
  Settings: SettingsScreen,
});

SettingsStack.navigationOptions = {
  tabBarLabel: 'Settings',
  tabBarIcon: ({ focused }) => (
    <TabBarIcon
      focused={focused}
      name={Platform.OS === 'ios' ? 'ios-options' : 'md-options'}
    />
  ),
};

export default createBottomTabNavigator({
  HomeStack,
  SettingsStack,
});

将标签添加到React Native Maps中

1 个答案: