Question

我有一个帖子列表，其中点击一个将切换帖子并显示其评论。我希望根据帖子是否切换来有条件地加载和显示评论，但是我无法在我的方法中访问状态，检查帖子是否被切换。

上下文应该是否与箭头函数自动绑定？

var PostList = React.createClass({ 
  componentDidMount() {
    this.state = {};     
    const posts = this.props.posts;      
    posts.forEach(function(post) {         
      this.state[post._id] = false;
    });        
  },

  isToggled(post) {                
    return this.state[post];      
  },

  render: function() {
    var postList = posts.map((post,index) => (
    <div class=“post”>
      {post.content}<br/>     
      {this.isToggled(post._id) ?       
      <Comments postId={post._id}/>     
      :''}
    </div>
  ))
 }

结果：

TypeError: Cannot read property 'idyadayada' of null

Answer 1

USe this.setState outside the forEach




getInitialState(){
  return {
  }
}
       componentDidMount() {
            this.state = {};                 
            const posts = this.props.posts;           
            var newState = {} ;      
            posts.forEach(function(post) {                     
              newState[post._id] = false;
            });              
            this.setState({
              state: newState
            }      
          },

将状态绑定到React中map函数内的条件语句

1 个答案: