将路由器ID作为参数

Question

在我的app.js组件中，我有一个名为“食谱”的数组，它必须包含一些元素，我想在路由器中以id的形式呈现这些元素。 App组件将其渲染到配方组件中。

我在这里有一些代码，但是无法正常工作。我已经整夜尝试了，但是我找不到错误。我是新来的反应者，所以也许您可以看到我看不到的错误。

App.js

    import React, { Component } from "react";
import "./App.css";
import Recipes from "./components/Recipes";
import { Router } from "@reach/router";
import Recipe from "./components/Recipe ";
import Nav from "./components/Nav";
import About from "./components/About";

class App extends Component {
  constructor(props) {
    super(props);

    this.state = {
      recipes: [
        {
          id: 1,
          title: "Drink",
          image: "https://picsum.photos/id/395/200/200"
        },
        { id: 2, title: "Pasta", image: "https://picsum.photos/id/163/200/200" }
      ]
    };
  }

  getRecipe(id) {
    //Number(id)

    return this.state.recipes.find(e => e.id === Number(id));
  }

  render() {
    return (
      <React.Fragment>
        Recipes
        {/*Sending the props from this component to the recipes component so it can be rendered there. And shown here
               <Recipes recipes={this.state.recipes}></Recipes>
          */}
        <Nav></Nav>
        <Router>
          <About path="/about"></About>
          <Recipe
            path="/recipe/:id"
            loadRecipe={id => this.getRecipe(id)}
          ></Recipe>
        </Router>
      </React.Fragment>
    );
  }
}

export default App;

Recipe.js

import React, { Component } from "react";

class Recipe extends Component {
  constructor(props) {
    super(props);

    this.state = {
      // See App.js for more details. loadRecipe is defined there.
      recipe: this.props.loadRecipe(this.props.id)
    };
  }

  render() {
    // In case the Recipe does not exists, let's make it default.
    let title = "Recipe not found";

    // If the recipe *does* exists, make a copy of title to the variable.
    if (this.state.recipe) {
      title = this.state.recipe.title;
    }

    return (
      <React.Fragment>
        <h1>The recipe:</h1>
        <p>{title}</p>
        {/* TODO: Print the rest of the recipe data here */}
      </React.Fragment>
    );
  }
}

export default Recipe;

我有这两个组成部分，我不知道怎么了，我没有收到任何错误。

Answer 1

我们需要在某处添加一个Route组件以获得所需的功能。您需要执行以下两项操作之一。可以使配方组件成为Route组件，或者将其保留原样并将其包装在Route Component中，然后使用渲染道具。

const Recipe = (props) => {
  <Route {...props}>
     // This is where your actual recipe component will live
  </Route>
}

然后您将可以

<Recipe
  path="/recipe/:id"
  loadRecipe={this.getRecipe}>
</Recipe>

对于loadRecipe部分，您可能只需要向下传递该函数，然后在Recipe组件中使用它。您应该从Route组件获取ID。

或

  <Route path="/recipe/:id" render={()=> <Recipe passDownSomething={this.state} />} />

一旦进行了此更改，您就可以使用可信赖的console.log来弄清楚要获得的道具并进行必要的调整。