反应本机传递阵列在clonewithrows中

Question

我想将数组传递到clonewithrows方法。以下是代码

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ListView

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

我遇到了错误未定义不是对象（评估'_this.state.todolistarray'）

我无法解决这个。请指导我！

谢谢

Answer 1

尝试这个 -

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

您在设置它之前先访问state对象。因此它返回undefined。尝试这样

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，当todoListArray内容更改时，您可以将其设置为

的dataSource

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

Answer 3

Vinayr给出的上述答案给了我一个线索。

      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>} />

它有效！

谢谢