从变量React-Native

时间:2019-05-02 13:50:10

标签: javascript json react-native react-native-flatlist

我正在使用react-native-fs将JSON文件存储在本地存储中 并从JSON文件中提取数据并将其存储在变量中。

我想获取存储在变量中的数据并在FlatList上将其充气。

我尝试过

// getting data from the local file
var path = RNFS.DocumentDirectoryPath + '/test.json';
return RNFS.readFile(path, 'utf8')
  .then((success) => {
      console.log(success);//Data is storing successfully see console output below
      this.setState({        
      isLoading: false,
      dataSource: success.recordset //data is not getting separated with respect to recordset 
    });
    console.log(dataSource);//see outpout below
  })
  .catch((err) => {
    console.log(err.message);
  });

console.log(成功)输出

  

[{“ recordset”:[[{“ id”:1,“ UPRN”:552,“ SiteName”:“ County Hall”,“ DueDate”:“ 2019-04-26T00:00:00.000Z”, “ SurveyStatus”:“已完成”,“ SyncStatus”:“已完成”},{“ id”:2,“ UPRN”:554,“ SiteName”:“ County Hall 2”,“ DueDate”:“ 2019-03-01T00 :00:00.000Z“,” SurveyStatus“:”已完成“,” SyncStatus“:”正在同步“},{” id“:3,” UPRN“:1524,” SiteName“:” County Hall 3“ ,“ DueDate”:“ 2019-03-02T00:00:00.000Z”,“ SurveyStatus”:“进行中”,“ SyncStatus”:null},{“ id”:4,“ UPRN”:2546, “ SiteName”:“ County Hall 4”,“ DueDate”:“ 2019-03-15T00:00:00.000Z”,“ SurveyStatus”:null,“ SyncStatus”:null},{“ id”:5,“ UPRN” :2156,“ SiteName”:“ County Hall 5”,“ DueDate”:“ 2019-07-01T00:00:00.000Z”,“ SurveyStatus”:null,“ SyncStatus”:null},{“ id”:6, “ UPRN”:8945,“ SiteName”:“ County Hall 6”,“ DueDate”:“ 2019-06-01T00:00:00.000Z”,“ SurveyStatus”:null,“ SyncStatus”:null},{“ id” :7,“ UPRN”:5214,“ SiteName”:“ County Hall 7”,“ DueDate”:“ 2020-06-01T00:00:00.000Z”,“ SurveyStatus”:null,“ SyncStatus”:null}]]]

console.log(dataSource)输出

  

数据源未定义

平面列表代码

    <FlatList
      data={this.state.dataSource}
      renderItem={({item}) =>
      <View style={styles.flatview}>
        <Text style={styles.name}>{item.UPRN}</Text>
        <Text style={styles.email}>{item.SiteName}</Text>
        <Text style={styles.email}>{item.DueDate}</Text>
        <Text style={styles.email}>{item.SurveyStatus}</Text>
        <Text style={styles.email}>{item.SyncStatus}</Text>
      </View>
      }
      keyExtractor={item => item.id}
    />

如何在FlatList中针对ID填充此数据?

2 个答案:

答案 0 :(得分:0)

这里发生了一些事情。

首先,您的dataSource is not defined消息是因为console.log语句不在RNFS.readFile结果的范围内。

第二,您需要解析JSON以将json文件的内容转换为对象,例如:

JSON.parse(success).then(result => this.setState({dataSource, result[0].recordset})

第三,看起来recordset在一个数组中,这就是为什么在上面将其称为result[0].recordset

答案 1 :(得分:0)

就像这样做


var path = RNFS.DocumentDirectoryPath + '/test.json';
return RNFS.readFile(path, 'utf8')
  .then((success) => {
      console.log(success);//Data is storing successfully see console output below

   const dataSource = success[0].recordset[0]

 this.setState({        
      isLoading: false,
      dataSource
    });
    console.log(dataSource);//see outpout below
  })
  .catch((err) => {
    console.log(err.message);
  });

该错误是因为您正在使用数据源,并且它是undefined。您需要定义您正在使用的变量。

,然后尝试将json数组格式化为

{"recordset":[{"id":1,"UPRN":552,"SiteName":"County Hall","DueDate":"2019-04-26T00:00:00.000Z","SurveyStatus":"Completed","SyncStatus":"Completed"},{"id":2,"UPRN":554,"SiteName":"County Hall 2","DueDate":"2019-03-01T00:00:00.000Z","SurveyStatus":"Completed","SyncStatus":"sync-in-progress"},{"id":3,"UPRN":1524,"SiteName":"County Hall 3","DueDate":"2019-03-02T00:00:00.000Z","SurveyStatus":"Survey-in-progress","SyncStatus":null},{"id":4,"UPRN":2546,"SiteName":"County Hall 4","DueDate":"2019-03-15T00:00:00.000Z","SurveyStatus":null,"SyncStatus":null},{"id":5,"UPRN":2156,"SiteName":"County Hall 5","DueDate":"2019-07-01T00:00:00.000Z","SurveyStatus":null,"SyncStatus":null},{"id":6,"UPRN":8945,"SiteName":"County Hall 6","DueDate":"2019-06-01T00:00:00.000Z","SurveyStatus":null,"SyncStatus":null},{"id":7,"UPRN":5214,"SiteName":"County Hall 7","DueDate":"2020-06-01T00:00:00.000Z","SurveyStatus":null,"SyncStatus":null}]}

因为您访问了错误的变量