当新道具到达时，子组件不会更新

Question

Props归结为子组件，它不会触发任何东西。 父组合和子组件都有代码。 我在父类中使用了componentDidMount(){}。 并在render子组件中设置props。在子类中，我使用了componentWillReceiveProps(){}。但是在孩子this.setState(){}中并没有改变状态。 伙计们帮助我。我可以弄清楚它为什么不起作用。

父：

class Recipes extends React.Component{
    constructor(props){
        super(props);
        this.state = {
            recipes: [], 
            Loaded: false 
        };
        this.getRec = this.getRec.bind(this);
        this.views = this.views.bind(this);
    }

    shouldComponentUpdate(nextProps, nextState){
        console.log(nextState);
        if (nextState.Loaded !== this.state.Loaded || nextProps !== this.props){
            return true;
        }
    }
    componentDidUpdate(){

    }
    componentWillMount(){
        this.views();
    }
    componentDidMount(){
        this.getRec();
    }
    componentWillUnmount(){

    }
    componentWillUpdate(){

    }
    getRec(_){
        fetch('http://localhost:5000/recipes')
        .then(response => response.json())
        .then(data => {
            this.setState({recipes: data, Loaded: true});
        })
        .then(data => this.render())
        .catch(err => console.log(err))
    }
    views(){
        const {recipes} = this.state;
        const howManyRecipes = recipes.length;
        const view = howManyRecipes > 0 ? 'hi' : <Route component={CreateProposal}/>
    }
    render() {
        const {recipes} = this.state;
        const howManyRecipes = recipes.length;
        console.log(howManyRecipes);
        return (
            <div>
                <div>Our community did {howManyRecipes} recipes</div>
                <RecipeList recipeList={this.state.recipes} Loaded={this.state.Loaded}/>
            </div>     
        )
    }
}

子：

class RecipeList extends Component{
    constructor(props){
        super(props); 
        this.state = {
            recipes: this.props.recipeList,
            loaded: this.props.Loaded
        }
        console.log(this.state.loaded);
        this.renderRec = this.renderRec.bind(this);
    }
    componentWillReceiveProps(nextProps){
        var answ = nextProps !== this.props;
        this.setState((prevState) => {return (prevState.recipes: nextProps.recipeList.data)});
        console.log(this.state, nextProps.recipeList.data, answ);
        return answ;
    }
    // shouldComponentUpdate(nextProps, nextState){
    //     var answ = nextState.loaded !== this.state.loaded;
    //     console.log("should component update? " + answ);
    //     return answ;
    // }
    renderRec(recipe){
        return <div key={recipe.id}>{recipe.name}</div>
    }
    render(){
        return(
            <div>
                <div>{this.state.recipes.length}</div>
                {this.state.recipes.map(this.renderRec)}
            </div>
        );
    }
}