Question

我目前正在学习React Native。我想写一个ListView。我正在关注的教程使用了不推荐使用的方法componentWillMount，现在将其称为UNSAFE_componentWillMount。我用谷歌搜索，有人说应该用componentDidMount替换该方法。我的问题是，当我将此方法添加到代码中时，应用程序中断了。

代码如下：

/* @flow */

import React, { Component } from "react";
import { ListView } from "react-native";
import { connect } from "react-redux";
import PropTypes from "prop-types";
import ListItem from "./ListItem";

class LibraryList extends Component {
  componentDidMount = () => {
    const ds = new ListView.DataSource({
      rowHasChanged: (r1, r2) => r1 !== r2
    });

    this.dataSource = ds.cloneWithRows(this.props.libraries);
  };

  renderRow = library => <ListItem library={library} />;

  render() {
    return <ListView dataSource={this.dataSource} renderRow={this.renderRow} />;
  }
}

LibraryList.propTypes = {
  libraries: PropTypes.array
};

const mapStateToProps = state => {
  return { libraries: state.libraries };
};

export default connect(mapStateToProps)(LibraryList);

这是我收到TypeError: Cannot read property 'rowIdentities' of undefined的错误消息。我应该在这里使用哪种方法，或者该如何解决？

Answer 1

我改用FlatList解决了这个问题。我发现不推荐使用ListView :)这是我最终使用的代码：

/* @flow */

import React, { Component } from "react";
import { FlatList } from "react-native";
import { connect } from "react-redux";
import PropTypes from "prop-types";
import ListItem from "./ListItem";

class LibraryList extends Component {
  state = {
    dataSource: []
  };
  componentDidMount = () => {
    this.setState({ dataSource: this.props.libraries });
  };

  renderRow = ({ item: library }) => <ListItem library={library} />;

  render() {
    return (
      <FlatList
        data={this.state.dataSource}
        renderItem={this.renderRow}
        keyExtractor={item => item.id.toString()}
      />
    );
  }
}

LibraryList.propTypes = {
  libraries: PropTypes.array
};

const mapStateToProps = state => {
  return { libraries: state.libraries };
};

export default connect(mapStateToProps)(LibraryList);

React Native：如何使用ListView处理生命周期方法的弃用？

1 个答案: