保持当前尺寸状态的简单方法，即使在窗口调整大小后:

//set up defaults on page mount
componentDidMount() {
  this.state = { width: 0, height: 0 };
  this.getDimensions(); 

  //add dimensions listener for window resizing
  window.addEventListener('resize', this.getDimensions); 
}

//remove listener on page exit
componentWillUnmount() {
  window.removeEventListener('resize', this.getDimensions); 
}

//actually set the state to the window dimensions
getDimensions = () => {
  this.setState({ width: window.innerWidth, height: window.innerHeight });
  console.log(this.state);
}

我发现了一个简单的组合QoP和speckledcarp的答案，使用React Hooks和调整大小功能，代码行数略少:

const [width, setWidth]   = useState(window.innerWidth);
const [height, setHeight] = useState(window.innerHeight);
const updateDimensions = () => {
    setWidth(window.innerWidth);
    setHeight(window.innerHeight);
}
useEffect(() => {
    window.addEventListener("resize", updateDimensions);
    return () => window.removeEventListener("resize", updateDimensions);
}, []);

哦，是的，确保resize事件是双引号，而不是单引号。这一点让我有点不安;)

@speckledcarp的回答很好，但是如果你需要在多个组件中使用这个逻辑，那么可能会很乏味。您可以将其重构为HOC(高阶组件)，以使此逻辑更易于重用。

withWindowDimensions.jsx

import React, { Component } from "react";

export default function withWindowDimensions(WrappedComponent) {
    return class extends Component {
        state = { width: 0, height: 0 };

        componentDidMount() {
            this.updateWindowDimensions();
            window.addEventListener("resize", this.updateWindowDimensions);
        }

        componentWillUnmount() {
            window.removeEventListener("resize", this.updateWindowDimensions);
        }

        updateWindowDimensions = () => {
            this.setState({ width: window.innerWidth, height: window.innerHeight });
        };

        render() {
            return (
                <WrappedComponent
                    {...this.props}
                    windowWidth={this.state.width}
                    windowHeight={this.state.height}
                    isMobileSized={this.state.width < 700}
                />
            );
        }
    };
}

然后在你的主组件中:

import withWindowDimensions from './withWindowDimensions.jsx';

class MyComponent extends Component {
  render(){
    if(this.props.isMobileSized) return <p>It's short</p>;
    else return <p>It's not short</p>;
}

export default withWindowDimensions(MyComponent);

你也可以“堆叠”hoc，如果你有另一个你需要使用，例如withthrouter (withWindowDimensions(MyComponent))

编辑:我现在会用React钩子(上面的例子)，因为它们解决了hoc和类的一些高级问题

在这里，您可以将投票次数最多的答案包装在一个节点包中(已测试，typescript)，以便使用。

安装:

npm i @teambit/toolbox.react.hooks.get-window-dimensions

用法:

import React from 'react';
import { useWindowDimensions } from '@teambit/toolbox.react.hooks.get-window-dimensions';

const MyComponent = () => {
  const { height, width } = useWindowDimensions();

  return (
    <>
      <h1>Window size</h1>
      <p>Height: {height}</p>
      <p>Width: {width}</p>
    </>
  );
};

React原生web有一个useWindowDimensions钩子，可以使用:

    import { useWindowDimensions } from "react-native";
    const dimensions = useWindowDimensions()

用一点打字稿

import { useState, useEffect } from 'react'; interface WindowDimentions { width: number; height: number; } function getWindowDimensions(): WindowDimentions { const { innerWidth: width, innerHeight: height } = window; return { width, height }; } export default function useWindowDimensions(): WindowDimentions { const [windowDimensions, setWindowDimensions] = useState<WindowDimentions>( getWindowDimensions() ); useEffect(() => { function handleResize(): void { setWindowDimensions(getWindowDimensions()); } window.addEventListener('resize', handleResize); return (): void => window.removeEventListener('resize', handleResize); }, []); return windowDimensions; }