init project

docs/data/material/components/backdrop/SimpleBackdrop.tsx

@@ -0,0 +1,27 @@
+import * as React from 'react';
+import Backdrop from '@mui/material/Backdrop';
+import CircularProgress from '@mui/material/CircularProgress';
+import Button from '@mui/material/Button';
+
+export default function SimpleBackdrop() {
+  const [open, setOpen] = React.useState(false);
+  const handleClose = () => {
+    setOpen(false);
+  };
+  const handleOpen = () => {
+    setOpen(true);
+  };
+
+  return (
+    <div>
+      <Button onClick={handleOpen}>Show backdrop</Button>
+      <Backdrop
+        sx={(theme) => ({ color: '#fff', zIndex: theme.zIndex.drawer + 1 })}
+        open={open}
+        onClick={handleClose}
+      >
+        <CircularProgress color="inherit" />
+      </Backdrop>
+    </div>
+  );
+}