在 cloneWithRows 中反应本机传递数组

Question

我想将一个数组传递给 cloneWithRows 方法。下面是代码

export default class FirstReactNativeApp extends Component {

          constructor() {
            super();
            const ds = new ListView.DataSource({rowHasChanged: (r1, r2) => r1 !== r2});

          this.state = {
            modalVisible: false,
            todoText:'',
            todoListArray:['foo 1','foo 2'],
           dataSource: ds.cloneWithRows(this.state.todoListArray)

          };
        }

这是列表视图

<ListView
        dataSource={this.state.dataSource}
        renderRow={(rowData) => <Text>{JSON.stringify(rowData)</Text>}
/>

我遇到了错误 undefined 不是一个对象（评估'_this.state.todoListArray'）

我无法解决this.Please指导我！

谢谢

Answer 1

试试这个 -

constructor() {
  super();
  this.ds = new ListView.DataSource({rowHasChanged: (r1, r2) => r1 !== r2});

  this.state = {
    modalVisible: false,
    todoText:'',
    todoListArray:['foo 1','foo 2'],
  };
}

<ListView
        dataSource={this.ds.cloneWithRows(this.state.todoListArray)}
        renderRow={(rowData) => <Text>{JSON.stringify(rowData)</Text>}
/>

Answer 2

您在设置 state 对象之前访问它。所以它 returns undefined。像这样尝试

export default class FirstReactNativeApp extends Component {

      constructor() {
        super();
        const ds = new ListView.DataSource({rowHasChanged: (r1, r2) => r1 !== r2});

      this.state = {
        modalVisible: false,
        todoText:'',
        todoListArray:['foo 1','foo 2'],
       dataSource: ds.cloneWithRows(['foo 1','foo 2'])

      };
  }

然后以后todoListArray内容变化时，可以设置成dataSource如

this.setState({
                dataSource: this.state.dataSource.cloneWithRows(this.state.todoListArray),
              });

Answer 3

以上vinayr的回答给了我一个线索

      this.state = {
        modalVisible: false,
        todoText:'',
        todoListArray:['foo 1','foo 2'],
        dataSource: ds

      };

然后在列表视图中

<ListView
  dataSource= {this.state.dataSource.cloneWithRows(this.state.todoListArray)}
  renderRow={(rowData) => <Text>{rowData}</Text>} />

有效！

谢谢

在 cloneWithRows 中反应本机传递数组

react native passing array in cloneWithRows

android

listview

react-jsx

react-native