javascript - 右滑 react native 删除列表项

Question

//这里我试图从平面列表中删除列表项。 数据是从 Flat List 上的 JSON 填充的，现在我必须删除特定的列表项数据表单列表，因为我正在使用“Swipeout”。但出现错误“类型错误:未定义不是对象(评估 this.2.viewNote.bind”)
请帮忙 。哪里出了问题，我该怎么做

import React, { Component } from 'react';
import { View, Text, TextInput,   
FooterTab,Button,TouchableOpacity, ScrollView, StyleSheet,
ActivityIndicator ,Header,FlatList} from 'react-native';
import {Icon} from 'native-base';
import { Table, Row, Rows } from 'react-native-table-component';
import { createStackNavigator } from 'react-navigation';  
import { SearchBar } from 'react-native-elements';
import Swipeout from 'react-native-swipeout';

let swipeBtns = [{
    text: 'Delete',
    backgroundColor: 'red',
    underlayColor: 'rgba(0, 0, 0, 1, 0.6)',
    onPress: () => { this.deleteNote(item) }
}];

export default class OpenApplianceIssue extends Component {


  constructor() {
      super();
      this.state = {
          AbcSdata: null,
          loading: true,
          search: '',
          tableData: [], qrData: '', selectedPriority: '',
          selectedIssue: '', selectedReason: '', selectedTriedRestart: '',
          selectedPowerLED: '', selectedBurning: '', selectedNoise: '',
      };
      this.setDate = this.setDate.bind(this);
  }

  setDate(newDate) {
  }


  _loadInitialState = async () => {
      const { navigation } = this.props;
      const qdata = navigation.getParam('data', 'NA').split(',');
      var len = qdata.length;
      const tData = [];
      console.log(len);
      for(let i=0; i<len; i++)
      {
          var data = qdata[i].split(':');
          const entry = []
          entry.push(`${data[0]}`);
          entry.push(`${data[1]}`);
          tData.push(entry);
      }
      this.setState({tableData: tData } );

      console.log(this.state.tableData);
      this.setState({loading: true});
  }

  componentDidMount() {
    this._loadInitialState().done(); 
    this.createViewGroup();
  }

  createViewGroup = async () => {
    try {
      const response = await fetch(
        'http:/Dsenze/userapi/sensor/viewsensor',
        {
          method: 'POST',
          headers: {
            Accept: 'application/json',
            'Content-Type': 'application/json',
          },
          body: JSON.stringify({
           "password": 'admin',
            "username": 'admin',
            "startlimit":"0",
            "valuelimit":"10",
          }),
        }
      );

      const responseJson = await response.json();

      const { sensorData } = responseJson;


      this.setState({
        AbcSdata: sensorData,
        loading: false,
      });
    } catch (e) {
      console.error(e);
    }
  };


  updateSearch = search => {
    this.setState({ search });
  };
  keyExtractor = ({ id }) => id.toString();
  keyExtractor = ({ inventory }) => inventory.toString();

  renderItem = ({ item }) => (


    <Swipeout right={swipeBtns}>
    <TouchableOpacity
      style={styles.item}
      activeOpacity={0.4}
      onPress={this.viewNote.bind(this, item)} >

      <Text >Id : {item.id}</Text>
      <Text>Inventory : {item.inventory}</Text>
      <Text>SensorType : {item.sensorType}</Text>
      <Text>TypeName : {item.typeName}</Text>
    </TouchableOpacity>
    </Swipeout>
  );
  viewNote(item) {
    this.props.navigator.push({
      title: 'The Note',
      component: ViewNote,
      passProps: {
        noteText: item,
        noteId: this.noteId(item),
      }
    });
  }


 onClickListener = (viewId) => {
    if(viewId == 'tag')
    {
      this.props.navigation.navigate('AddSensors');
    }}

    renderSeparator = () => {
      return (
        <View
          style={{
            height: 1,
            width: "86%",
            backgroundColor: "#CED0CE",
          }}
        />
      );
    };


  render() {
    const { loading, AbcSdata } = this.state;
    const state = this.state;

    return (
      <ScrollView>
        <View style={styles.container1}>


            <Button full rounded
              style={{fontSize: 20, color: 'green'}}
               styleDisabled={{color: 'red'}}
               onPress={() => this.onClickListener('tag')}
                  title="Add Sensors"
                  >
                      Add Sensors
                    </Button>

        </View>

        <View style={styles.container1}>
          {this.state.loading ? (
            <ActivityIndicator size="large" />

          ) :

          (
            <FlatList 
              data={AbcSdata}
              renderItem={this.renderItem}
             keyExtractor={this.keyExtractor}
             ItemSeparatorComponent={this.renderSeparator}

            />
          )}
        </View>


        <View>
          <Text 
          style={{alignSelf: 'center', fontWeight: 'bold', color: 'black'}} >
          Inventory Details
          </Text>

            <Table borderStyle={{borderWidth: 2, borderColor: '#c8e1ff', padding:10,paddingBottom: 10}}>
            <Rows data={state.tableData} textStyle={styles.text}/>
            </Table>
            </View>
      </ScrollView>
    );
  }
}   




const styles = StyleSheet.create(
    {
        container1:
        {
            flex: 1,
            alignItems: 'stretch',
            fontFamily: "vincHand",
            color: 'blue'
        },
        header_footer_style:{

          width: '100%', 
          height: 44, 
          backgroundColor: '#4169E1', 
          alignItems: 'center', 
          justifyContent: 'center',
          color:'#ffffff',


        },
        Progressbar:{
            justifyContent: 'center',
            alignItems: 'center',
            color: 'blue',

        },
        ListContainer :{
            borderColor: '#48BBEC',
            backgroundColor: '#000000',
            color:'red',
            alignSelf: 'stretch' ,
        },

        container2:
        {
            flex: 1,
            justifyContent: 'center',
            alignItems: 'stretch',
            paddingHorizontal: 15
        },

        inputBox:{
            width:300,
            borderColor: '#48BBEC',
            backgroundColor: '#F8F8FF',
            borderRadius:25,
            paddingHorizontal:16,
            fontSize:16,
            color:'#000000',
            marginVertical:10, 

        },
        button:{
            width:300,
            backgroundColor:'#4169E1',
            borderRadius:25,
            marginVertical:10,
            paddingVertical:16
        },

        buttonText:{
        fontSize:16,
        fontWeight:'500',
        color:'#ffffff',
        textAlign:'center'

        },
        textStyle:{
          fontSize:16,
        fontWeight:'500',
        color:'#ffffff',
        textAlign:'center'

        },

        item:
        {
            padding: 15
        },

        text:
        {
            fontSize: 18
        },
        button:{
            width:300,
            backgroundColor:'#4169E1',
            borderRadius:25,
            marginVertical:10,
            paddingVertical:16
        },
        buttonText:{
            fontSize:16,
            fontWeight:'500',
            color:'red',
            textAlign:'center'

            },
        separator:
        {
            height: 2,
            backgroundColor: 'rgba(0,0,0,0.5)'
        },
        container: { flex: 1, padding: 16, paddingTop: 30, backgroundColor: '#fff' },
        head: { height: 40, backgroundColor: '#f1f8ff' },
        text: { margin: 6 }
    });

Thanks .

Answer 1

首先， 尽可能尝试使用粗箭头函数，这将自动解决您的绑定(bind)问题。

1. 您必须在您的 flatlist 中使用 extraData= {this.state.activeRow} 和新添加的状态 activeRow。<
2. 我已经更新了你的 renderItem()。

检查以下更新的代码。希望这会有所帮助。

 import * as React from 'react';
 import { View, Text, TextInput,
  FooterTab, Button, TouchableOpacity, ScrollView, StyleSheet,
  ActivityIndicator, Header, FlatList } from 'react-native';
  import { Table, Row, Rows } from 'react-native-table-component';
import { createStackNavigator } from 'react-navigation';
import { SearchBar } from 'react-native-elements';

import { Constants } from 'expo';

// You can import from local files
import AssetExample from './components/AssetExample';

// or any pure javascript modules available in npm
import { Card } from 'react-native-paper';
import Swipeout from 'react-native-swipeout';


export default class App extends React.Component {

constructor() {
    super();
    this.state = {
      AbcSdata: null,
      loading: true,
      search: '',
      tableData: [], qrData: '', selectedPriority: '',
      selectedIssue: '', selectedReason: '', selectedTriedRestart: '',
      selectedPowerLED: '', selectedBurning: '', selectedNoise: '',
      rowID:'',
      activeRow: null
    };
    this.setDate = this.setDate.bind(this);
  }

swipeBtns = [{
  text: 'Delete',
  type: 'delete',
  backgroundColor: 'red',
  underlayColor: 'rgba(0, 0, 0, 1, 0.6)',
  onPress: () => { 
    console.log("Deleting Row with Id ", this.state.activeRow);
    this.deleteNote(this.state.activeRow);
  }
}];

removeItem = (items, i) =>
  items.slice(0, i).concat(items.slice(i + 1, items.length));

deleteNote = (rowIndex) => {

  //add your custome logic to delete the array element with index.
  // this will temporary delete from the state.
  let filteredData = this.removeItem(this.state.AbcSdata,rowIndex);
  this.setState({AbcSdata: [] },()=> {
    this.setState({AbcSdata: filteredData },()=> {console.log("Row deleted.", rowIndex)});
  });
};

  setDate(newDate) {
  }


  _loadInitialState = async () => {
    const { navigation } = this.props;
    const qdata = navigation.getParam('data', 'NA').split(',');
    var len = qdata.length;
    const tData = [];
    console.log(len);
    for (let i = 0; i < len; i++) {
      var data = qdata[i].split(':');
      const entry = []
      entry.push(`${data[0]}`);
      entry.push(`${data[1]}`);
      tData.push(entry);
    }
    this.setState({ tableData: tData });

    console.log(this.state.tableData);
    this.setState({ loading: true });

  }

  componentDidMount() {
    //this._loadInitialState().done();
    this.createViewGroup();
  }

  createViewGroup = async () => {
    try {
      const response = await fetch(
        '/Dsenze/userapi/sensor/viewsensor',
        {
          method: 'POST',
          headers: {
            Accept: 'application/json',
            'Content-Type': 'application/json',
          },
          body: JSON.stringify({
            "password": 'admin',
            "username": 'admin',
            "startlimit": "0",
            "valuelimit": "10",
          }),
        }
      );

      const responseJson = await response.json();

      const { sensorData } = responseJson;


      this.setState({
        AbcSdata: sensorData,
        loading: false,
      });
    } catch (e) {
      console.error(e);
    }
  };



  updateSearch = search => {
    this.setState({ search });
  };
  keyExtractor = ({ id }) => id.toString();
  keyExtractor = ({ inventory }) => inventory.toString();

onSwipeOpen(rowId, direction) {
    if(typeof direction !== 'undefined'){
        this.setState({activeRow:rowId});
        console.log("Active Row",rowId);
    }
}

  renderItem = ({ item, index }) => (

    <Swipeout
      right={this.swipeBtns}
      close={(this.state.activeRow !== index)}
      rowID={index}
      sectionId= {1}
      autoClose = {true}
      onOpen = {(secId, rowId, direction) => this.onSwipeOpen(rowId, direction)}

    >
      <TouchableOpacity
        style={styles.item}
        activeOpacity={0.4}
        onPress={this.viewNote(item)} >

        <Text >Id : {item.id}</Text>
        <Text>Inventory : {item.inventory}</Text>
        <Text>SensorType : {item.sensorType}</Text>
        <Text>TypeName : {item.typeName}</Text>
      </TouchableOpacity>
    </Swipeout>
  );
  viewNote =(item) => {
     this.props.navigator.push({
       title: 'The Note',
       component: this.ViewNote,
       passProps: {
         noteText: item,
         noteId: this.noteId(item),
       }
     });
    console.log("View Note Success");
  }


  onClickListener = (viewId) => {
    if (viewId == 'tag') {
      this.props.navigation.navigate('AddSensors');
    }
  }

  renderSeparator = () => {
    return (
      <View
        style={{
          height: 1,
          width: "86%",
          backgroundColor: "#CED0CE",
        }}
      />
    );
  };

  render() {
    const { loading, AbcSdata } = this.state;
    const state = this.state;

    return (
      <ScrollView>
        <View style={styles.container1}>


          <Button full rounded
            style={{ fontSize: 20, color: 'green' }}
            styleDisabled={{ color: 'red' }}
            onPress={() => this.onClickListener('tag')}
            title="Add Sensors"
          >
            Add Sensors
                        </Button>

        </View>

        <View style={styles.container1}>
          {this.state.loading ? (
            <ActivityIndicator size="large" />

          ) :

            (
              <FlatList
                data={AbcSdata}
                renderItem={this.renderItem}
                keyExtractor={this.keyExtractor}
                extraData= {this.state.activeRow}
                ItemSeparatorComponent={this.renderSeparator}

              />
            )}
        </View>


        <View>
          <Text
            style={{ alignSelf: 'center', fontWeight: 'bold', color: 'black' }} >
            Inventory Details
              </Text>

          <Table borderStyle={{ borderWidth: 2, borderColor: '#c8e1ff', padding: 10, paddingBottom: 10 }}>
            <Rows data={state.tableData} textStyle={styles.text} />
          </Table>
        </View>
      </ScrollView>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    paddingTop: Constants.statusBarHeight,
    backgroundColor: '#ecf0f1',
    padding: 8,
  },
  paragraph: {
    margin: 24,
    fontSize: 18,
    fontWeight: 'bold',
    textAlign: 'center',
  },
});