React Native cloneWithRows 错误 - 对象未定义 [英] React Native cloneWithRows error - object undefined

问题描述

我对这个框架很陌生.我正在使用 React-Native 中的 dataSource 制作一个基本的 ListView，其中包含我获取的数据.

I'm quite new to the framework. I'm making a basic ListView with dataSource in React-Native, with data that I fetch.

constructor(props){
    super(props);
    var dataSource = new ListView.DataSource({
        rowHasChanged: (r1, r2) => r1 !== r2,
    });
    this.state = {
        searchString: '',
        isLoading: false,
        message: '',
        jsonData: '',
    };
}


_fetchData(query){

    console.log(query);
    this.setState({ isLoading: true });

    fetch(query)
        .then(response => response.json())
        .then(responseData => {
            this._handleResponse(responseData);
            this.setState({
                message: 'seems like it worked!',
                dataSource: this.state.dataSource.cloneWithRows( responseData ),
            });
        })
        .catch(error => 
            this.setState({
                isLoading: false,
                message: this.state.message + ' --- ' + 'Something bad happened' + error
            })
        ).done(); 

}

我获取的数据是从 Twitter API 响应中提取的:

the data I fetch is an extract from a twitter API response:

{  "statuses": [
{
  "coordinates": null,
  "favorited": false,
  "truncated": false,
  "created_at": "Mon Sep 24 03:35:21 +0000 2012",
  "id_str": "250075927172759552",
  "retweet_count": 0,
  "in_reply_to_status_id_str": null,
  "id": 250075927172759552
}
]}

但是，我在 cloneWithRows 上收到undefined is not an object (evaluating 'dataSource.rowIdentities')"错误.当我在 iOS 8.4 和 9.1 上运行模拟时出现此错误.我可能遗漏了一些小东西并且被困了几个小时.有什么想法吗?

yet, I get a "undefined is not an object (evaluating 'dataSource.rowIdentities')" error on cloneWithRows. This error appears when I run the simulation on iOS 8.4 and 9.1. I'm probably missing something small and have been stuck for hours. Any ideas?

推荐答案

看代码，我猜你想在列表视图中显示状态.为此，将您的代码更改为 this.state.dataSource.cloneWithRows(responseData.statuses)

Looking at the code, I guess you want show the statuses inside listview. For that change your code to this.state.dataSource.cloneWithRows(responseData.statuses)

ListViewDataSource 源代码有详细的注释，解释了这个函数期望的格式 https://github.com/facebook/react-native/blob/62e8ddc20561a39c3c839ab9f83c95493df117c0/Libraries/CustomComponents/ListView/List1L5L一个>

ListViewDataSource source code has detailed comment which explains the format this function is expecting https://github.com/facebook/react-native/blob/62e8ddc20561a39c3c839ab9f83c95493df117c0/Libraries/CustomComponents/ListView/ListViewDataSource.js#L95-L110

更新:

在 state 对象上设置 dataSource 属性，将构造函数中的代码更改为

Set the dataSource property on state object, change your code in the constructor to

<代码>this.state = {搜索字符串:'',isLoading: 假，信息: ''，jsonData: '',数据源:数据源};

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