javascript - 侧边栏 DOM 与 Navbar 重叠，将其从 DOM 中移除

Question

您好，当用户单击汉堡菜单时，我使用 React 创建侧边栏，问题是当用户单击汉堡菜单时，侧边栏出现但导航栏消失，我如何同时呈现导航栏和侧边栏不相互叠加？

var app = document.getElementById('app');

class Navbar extends React.Component {
    constructor(props) {
        super(props);
        this.state = { 
            sidebarOn: false
        };
        this.onClickOpen = this.onClickOpen.bind(this);
    }
    
    onClickOpen(open) {
        console.log(open);
        if(open) {
            this.setState({sidebarOn: open});
            Menu();
        }
        
    }
    render() {
        return(
            <div>
            <header>    
            <nav class="navbar navbar-custom sticky-top">
                <a class="navbar-brand" href="#">TO DO LIST</a>
                <a class="burger-menu" href="#"><img src='/images/hamburger-icon.png' onClick={() => this.onClickOpen(true)}></img></a>
            </nav>
            </header>
        </div>
        );
    }
}



function Menu() {
    class Parent extends React.Component {
        constructor() {
            super();
            this.state = {
                burgerOn: "burger-right"
            };
        }
      render() {
        return (
            <div class={this.state.burgerOn}>
                      <div class="container">
                <form >
                    <div class="form-group task-title">
                    <label for="title">
                        Task Title
                    </label>
                    <input type="title" class="form-control" placeholder="Enter Task Title"></input>
                    </div>
                    <div class="form-group task-desc">
                        <label for="desc">Task Description</label>
                        <textarea type="text" class="form-control" id="desc" placeholder="Enter Task Description" rows="5"></textarea>
                    </div>
                </form>
                <div>
                <button type="button" class=" task-btn btn btn-primary">Create</button>
                </div>
                </div>
            </div>
        );
      } 
    }
    ReactDOM.render(<Parent />, app);
}

ReactDOM.render(<Navbar />, app);

var app = document.getElementById('app');

class Navbar extends React.Component {
    constructor(props) {
        super(props);
        this.state = { 
            sidebarOn: false
        };
        this.onClickOpen = this.onClickOpen.bind(this);
    }
    
    onClickOpen(open) {
        console.log(open);
        if(open) {
            this.setState({sidebarOn: open});
            Menu();
        }
        
    }
    render() {
        return(
            <div>
            <header>    
            <nav class="navbar navbar-custom sticky-top">
                <a class="navbar-brand" href="#">TO DO LIST</a>
                <a class="burger-menu" href="#"><img src='/images/hamburger-icon.png' onClick={() => this.onClickOpen(true)}></img></a>
            </nav>
            </header>
        </div>
        );
    }
}



function Menu() {
    class Parent extends React.Component {
        constructor() {
            super();
            this.state = {
                burgerOn: "burger-right"
            };
        }
      render() {
        return (
            <div class={this.state.burgerOn}>
                      <div class="container">
                <form >
                    <div class="form-group task-title">
                    <label for="title">
                        Task Title
                    </label>
                    <input type="title" class="form-control" placeholder="Enter Task Title"></input>
                    </div>
                    <div class="form-group task-desc">
                        <label for="desc">Task Description</label>
                        <textarea type="text" class="form-control" id="desc" placeholder="Enter Task Description" rows="5"></textarea>
                    </div>
                </form>
                <div>
                <button type="button" class=" task-btn btn btn-primary">Create</button>
                </div>
                </div>
            </div>
        );
      } 
    }
    ReactDOM.render(<Parent />, app);
}

ReactDOM.render(<Navbar />, app);

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.14.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.14.0/react-dom.min.js"></script>
<!DOCTYPE html>
<html>
<head> 
        <script src="https://unpkg.com/react@16/umd/react.production.min.js"></script>
        <script src="https://unpkg.com/react-dom@16/umd/react-dom.production.min.js"></script>
        <script src="https://unpkg.com/babel-standalone@6/babel.min.js"></script>
</head>
<body>   
        <div id="app"></div>
        <script type="text/babel" src="/js/app.js"></script>    
</body>
</html>

如截图所示，如果您单击损坏的图像链接，我的表单将覆盖 todolist 导航栏。

非常感谢您的建设性帮助:)

Answer 1

问题是当你想渲染侧边栏菜单时你正在使用这段代码

ReactDOM.render(<Parent />, app);

这意味着只需在您的 html 文件中的 app 元素中插入任何组件。结果就像清除之前渲染的组件并渲染新的组件。这就是您在这里看到的:

...some code
          } 
        }
        ReactDOM.render(<Parent />, app); <---- here
    }

    ReactDOM.render(<Navbar />, app); <---- and here

... morecode

您不需要直接在根元素中渲染刚刚创建的每个组件。 你只需要在其中渲染一次最上层的组件 所有其他组件都应嵌套在父组件中，这样您只会在 html 文件的根元素内呈现一个父组件，并且所有其他组件都将通过将它们导入内部来包含在其中你的父组件并在那里使用它们，如下所示:

import React from 'react'
import ReactDOM from 'react-dom'

import B from './B'

class A extends React.component {
   render() {
     return(
       <div>
         <B />
       </div>
     )
   }
}


ReactDOM.render(
  <A />,
  document.querySelector('#app')
)