如何在反应componentDidMount中设置状态与方法？

Question

码是这样的：

componentDidMount() { 
    this.setState(({getPublicTodosLength}, props) => ({ 
     getPublicTodosLength:() => this.getPublicTodosLengthForPagination() // no returned value 
    })); 
    } 
    getPublicTodosLengthForPagination = async() => { // get publicTodos length since we cannot get it declared on createPaginationContainer 
     const getPublicTodosLengthQueryText = ` 
      query TodoListHomeQuery {# filename+Query 
      viewer { 
       publicTodos { 
       edges { 
        node { 
        id 
        } 
       } 
       } 
      } 
      }` 
    const getPublicTodosLengthQuery = { text: getPublicTodosLengthQueryText } 
    const result = await this.props.relay.environment._network.fetch(getPublicTodosLengthQuery, {}) 
    return result.data.viewer.publicTodos.edges.length; 
    } 

getPublicTodosLengthForPagination不被调用和返回值不是assigned.Also，当我调用它马上例如无（）=>它的赋值是一个承诺？我期待int/number，edge.length的返回值。帮帮我？

Answer 1

返回的值未分配，因为您没有调用该函数而是分配它。

componentDidMount() { 
    this.setState(({getPublicTodosLength}, props) => ({ 
     getPublicTodosLength: this.getPublicTodosLengthForPagination() 
    })); 
    } 

Answer 2

我不知道你为什么要这样设置状态，也许你可以帮助解释你在做什么。在此期间不应该这样写：