如何在react-native中使用列表项制作搜索过滤器

Question

我一直想在这个列表项中添加搜索过滤器，但是有些困惑。如果您对此有经验，请查看我的代码。

import React, { Component } from 'react'; 
import {   Text,   View,   ScrollView,   TextInput, } from 'react-native'; 
import { List, ListItem } from 'react-native-elements'; 
import { users } from '../config/data';

class Feed extends Component {   constructor(props){
    super(props);
    this.state = {
      user:'',
    }   }   onLearnMore = (user) => {
    this.props.navigation.navigate('Details', { ...user });   };

  filterSearch(text){
    const newData = users.filter((item)=>{
      const itemData = item.name.first.toUpperCase()
      const textData = text.toUpperCase()
      return itemData.indexOf(textData)>-1
    })
    this.setState({
      text:text
    })   }

  render() {
    return (
      <ScrollView>
        <TextInput
            onChangeText={(text) => this.filterSearch(text)}
            value={this.state.text}
          />
        <List>
          {users.map((user) => (
            <ListItem
              key={user.login.username}
              roundAvatar
              avatar={{ uri: user.picture.thumbnail }}
              title={`${user.name.first.toUpperCase()} ${user.name.last.toUpperCase()}`}
              subtitle={user.email}
              onPress={() => this.onLearnMore(user)}
            />
          ))}
        </List>
      </ScrollView>
    );   } }

export default Feed;

我一直在浏览互联网，但发现大多数讨论的是ListView，而不是来自React-Native-Elements的列表项。请帮帮我！

- Billy Koswara

---

我在另一个问题中写了这个解决方案：https://dev59.com/NlcO5IYBdhLWcg3whiBx#55949691 - Metehan Senol

@MetehanSenol 谢谢您提供的参考。 - Billy Koswara

Answer 1

你几乎是正确的。你已经成功地过滤了你的用户，但是在列表中呈现出来的仍是未经过滤的用户。要轻松地改变这一点，你可以使用组件状态。 示例

import React, { Component } from 'react'; 
import {   Text,   View,   ScrollView,   TextInput, } from 'react-native'; 
import { List, ListItem } from 'react-native-elements'; 
import { users } from '../config/data';

class Feed extends Component {   
  constructor(props){
    super(props);
      this.state = {
        user:'',
        users: users // we are setting the initial state with the data you import
      }
  }   

  onLearnMore = (user) => {
    this.props.navigation.navigate('Details', { ...user });
  };

  filterSearch(text){
    const newData = users.filter((item)=>{
      const itemData = item.name.first.toUpperCase()
      const textData = text.toUpperCase()
      return itemData.indexOf(textData)>-1
    });
    this.setState({
      text:text,
      users: newData // after filter we are setting users to new array
    });
  }

  render() {
    // rather than mapping users loaded from data file we are using state value
    return (
      <ScrollView>
        <TextInput
            onChangeText={(text) => this.filterSearch(text)}
            value={this.state.text}
          />
        <List>
          {this.state.users.map((user) => (
            <ListItem
              key={user.login.username}
              roundAvatar
              avatar={{ uri: user.picture.thumbnail }}
              title={`${user.name.first.toUpperCase()} ${user.name.last.toUpperCase()}`}
              subtitle={user.email}
              onPress={() => this.onLearnMore(user)}
            />
          ))}
        </List>
      </ScrollView>
    );   } }

export default Feed;

- bennygenel

Answer 2

为什么我一直回答自己的问题

非常抱歉在这个论坛上浪费了一些空间，但我认为发布这个答案会帮助一些像我这样的初学者。

    import React, {Component} from 'react';
import { StyleSheet, Text, View, ListView, TouchableHighlight, TextInput} from 'react-native';
import { List, ListItem } from 'react-native-elements';
import { users } from '../config/data';

export default class Feed extends Component {
  constructor(props){
    super(props);
    const ds = new ListView.DataSource({rowHasChanged: (r1,r2) => r1 !== r2})
    this.state = {
      dataSource: ds.cloneWithRows(users),
      text:'',
    }
  }
  onLearnMore = (rowData) => {
    this.props.navigation.navigate('Details', { ...rowData });
  };
  renderRow(rowData){
    return(
        <ListItem
          key={rowData.login.username}
          roundAvatar
          avatar={{ uri: rowData.picture.thumbnail }}
          title={`${rowData.name.first.toUpperCase()} ${rowData.name.last.toUpperCase()}`}
          subtitle={rowData.email}
          onPress={() => this.onLearnMore(rowData)}
        />
    );
  }
  filterSearch(text){
      const newData = users.filter(function(item){
          const itemData = item.email.toUpperCase()
          const textData = text.toUpperCase()
          return itemData.indexOf(textData) > -1
      })
      this.setState({
          dataSource: this.state.dataSource.cloneWithRows(newData),
          text: text
      })
  }

  render() {
    return (
      <View style={{flex:1}}>
        <TextInput
          onChangeText={(text) => this.filterSearch(text)}
          value={this.state.text}
          />
        <ListView
          enableEmptySections={true}
          style={{marginHorizontal:10}}
          renderRow={this.renderRow.bind(this)}
          dataSource={this.state.dataSource}
        />
      </View>
    );
  }
}

只需比较问题代码和答案代码，最后通过阅读下面的链接获取答案：

https://react-native-training.github.io/react-native-elements/API/lists/

随时可以再次检查。

- Billy Koswara