如何在反应中的方法之间进行通信？

Question

我目前有两种方法，SelectedTopicPage组件即navigateNext和render。我想从navigateNext方法将topicPageNo的值传递给render方法。在React中推荐的方法是什么？当我试图声明：

topicPageNo = navigateNext.state.topicPageNo;

它给undefined error。

var SelectedTopicPage = React.createClass({ 
    navigateNext: function() { 
     let topicPageNo = '2'; 
     this.setState({topicPageNo : topicPageNo}); 
    }, 
    render: function() { 
     let topicsID = this.props.topicsID; 
     let navigateNext = this.navigateNext; 
     let topicPageNo = navigateNext.state.topicPageNo; 
     return (
      <div> 
       {this.props.topicPages.filter(function(topicPage) { 
        return topicPage.topic_no === topicsID && topicPage.topic_page_no === topicPageNo; // if condition is true, item is not filtered out 
       }).map(function (topicPage) { 
        return (
         <div> 
          <div> 
          <SelectedTopicPageMarkup headline={topicPage.headline} key={topicPage.topic_no}> 
           {topicPage.description} 
          </SelectedTopicPageMarkup> 
          </div> 
          <div> 
           <NextPrevBtn moveNext={navigateNext}/> 
          </div> 
         </div> 
        ); 
       })} 
      </div> 
     ); 
    } 
}); 

Answer 1

你必须使用this所以你的代码应该是let topicPageNo = this.state.topicPageNo;

和您的组件应该有一个像

getInitialState:function() 
    { 
     return{ 
     topicPageNo:0 
     } 
    }