在 React 应用程序上获取数据时如何添加加载微调器？

Question

How to add loading spinner while fetching. I want to add loading spinner on fetch data on my react app.

Answer 1

you can use react Suspense and lazy for it. here below is a code example.

import { Suspense, lazy } from "react";

import Loading from "./loading";
const Loaded = lazy(() => import("./loaded"));

const App = () => {
  return (
    <Suspense fallback={<Loading />}>
      <Loaded />
    </Suspense>
  );
};

you can read mode about the suspense here suspense

here is sandbox Link sanbox

Answer 2

You need to have a loading state based on how you are fetching the data for example if you are fetching data using axios you need to set the loading to true in the beginning of your fetch function and set it to false on receiving data or on error.

const App = () => {
  const [loading, setLoading] = useState(false);

  const fetchFunction = () => {
    setLoading(true);
    .
    .
    .
    if (data || error) {
      setLoading(false);
    }
  };

  if (loading) return <Loading />;

  return <Data />;
};