每天学习一个hooks useMount

  const useMount = (fn: () => void) => {
    // 判断一下，传如的fn是否时一个函数
    if (isFunction(fn)) {
      useEffect(() => {
        fn?.();
      }, []);
      return;
    }
    console.error(`useMount: parameter \`fn\` expected to be a function, but Got "${typeof fn}".`);
  };

import { useEffect, useState } from "React";
import { isFunction } from "lodash";
const UseMountDemo = () => {
  const [, setState] = useState({});
  const useMount = (fn: () => void) => {
    if (isFunction(fn)) {
      useEffect(() => {
        fn?.();
      }, []);
      return;
    }
    console.error(`useMount: parameter \`fn\` expected to be a function, but got "${typeof fn}".`);
  };
  useMount(() => {
    console.log("我只在初始化的时候运行一次");
  });
  console.log("组件渲染了");
  return <button onClick={() => setState({})}>重新render</button>;
};
export default UseMountDemo;