reactjs - 收到错误说 TypeError undefined is not an object

Question

我正在尝试在 Listview 中显示数据。首先，我根据用户在前一个屏幕上所做的选择过滤数据（JSON 文件）。我通过说将参数传递到下一个屏幕：

this.props.navigation.state.params.JSON_ListView_Clicked_Item)

根据上面的参数，我在render函数里面做了ListView.DataSource。唯一的原因是，我尝试在渲染函数中执行 ListView.DatSource，因为据我了解，这是唯一可以读取参数值的地方。当我尝试显示我的 listView 时，我收到一条错误消息：

TypeError undefined 不是对象。下面是屏幕截图：

下面是我的代码：

import React, { Component } from 'react';

import { StyleSheet, Text, View, ListView, ActivityIndicator, TextInput } from 'react-native';

import ServiceDetails from '../reducers/ServiceDetails';


class ServiceListDetails extends Component
{




  static navigationOptions =
  {
     title: 'SecondActivity',
  };




ListViewItemSeparator = () => {
  return (
    <View
      style={{
        height: .5,
        width: "100%",
        backgroundColor: "#000",
      }}
    />
  );
}


render()
  {


      var x =   this.props.navigation.state.params.JSON_ListView_Clicked_Item ;
      var newList = ServiceDetails.filter(obj => obj.fk === this.props.navigation.state.params.JSON_ListView_Clicked_Item)

      let ds = new ListView.DataSource({rowHasChanged: (r1, r2) => r1 !== r2});
      this.setState({
          dataSource: ds.cloneWithRows(newList)

      }
    );


    return(
      <View style={styles.MainContainer}>
             <ListView

                dataSource={this.dataSource}
                renderSeparator= {this.ListViewItemSeparator}
                renderRow={(rowData) => <Text>{rowData}</Text>}
/>

      </View>
    );

  }
}

下面是我的 JSON 文件：

[

    {
       "id":"1",
       "fk": "1",
       "addr": "TestAddress1",
       "phone": "[phone]",
       "LatL":"33.234567",
       "Long2":"117.284725",
       "Online": "x"
    },

    {
        "id":"2",
        "fk": "1",
        "addr": "TestAddress1",
        "phone": "(999)-999-9999",
        "LatL":"33.971110",
        "Long2":"117.31111",
        "Online": ""
     },
]

标签： reactjsreact-nativereact-android

Answer 1

您在定义 JSON 文件时是一个错误。在数组中的最后一个对象中","不需要它不是有效的 JSON 格式。

[

    {
        "id": "1",
        "fk": "1",
        "addr": "TestAddress1",
        "phone": "[phone]",
        "LatL": "33.234567",
        "Long2": "117.284725",
        "Online": "x"
    },{
        "id": "2",
        "fk": "1",
        "addr": "TestAddress1",
        "phone": "(999)-999-9999",
        "LatL": "33.971110",
        "Long2": "117.31111",
        "Online": "y"
    }
]