1. 创建方式

// render props
class Mouse extends Component {
    state = {
        x: 0,
        y: 0
    }
    handleMouseMove = e => {
        this.setState({
            x: e.clientX,
            y: e.clientY,
        })
    }
    componentDidMount() {
        window.addEventListener("mousemove", this.handleMouseMove)
    }
    componentWillUnmount() {
        window.removeEventListener("mousemove", this.handleMouseMove)
    }
    render() {
        const { flag, render, children } = this.props;
        return flag ? render(this.state) : children(this.state);
    }
}

// HOC
function withMouse(WrappedComponent) {
    class Mouse extends Component {
        state = {
            x: 0,
            y: 0
        }
        handleMouseMove = e => {
            this.setState({
                x: e.clientX,
                y: e.clientY,
            })
        }
        componentDidMount() {
            window.addEventListener("mousemove", this.handleMouseMove)
        }
        componentWillUnmount() {
            window.removeEventListener("mousemove", this.handleMouseMove)
        }
        render() {
            return <WrappedComponent {...this.state} {...this.props}></WrappedComponent>
        }
    }
    Mouse.displayName = `WithMouse${getDisplayName(WrappedComponent)}`
    return Mouse
}

function getDisplayName(WrappedComponent) {
    return WrappedComponent["displayName"] || WrappedComponent["name"] || "Component"
}

2. 使用方式

// render props
<Mouse flag={true} render={
                    mouse => {
                        return (
                            <div>
                                X: {mouse.x}, Y: {mouse.y}
                            </div>
                        )
                    }
                }></Mouse>
                <Mouse>
                    {
                        mouse => {
                            return (
                                <div style={{
                                    position: 'absolute',
                                    top: mouse.y - 50,
                                    left: mouse.x - 50,
                                    width: '100px',
                                    height: '100px',
                                    background: 'red'
                                }}>
                                </div>
                            )
                        }
                    }
                </Mouse>

// HOC
const Position = props => (
    <div>
        X:{props.x}, Y:{props.y}
    </div>
)

const Cart = props => (
    <div style={{
      position: 'absolute',
      top: props.y - 50,
      left: props.x - 50,
      width: '100px',
      height: '100px',
      background: 'red'
    }}></div>
)
const MousePosition = withMouse(Position);
const MouseCart = withMouse(Cart);