Backdrop 背景板
Backdrop 组件用于提供对特定元素或其部分的强调。
The backdrop signals to the user of a state change within the application and can be used for creating loaders, dialogs and more. 最简单的形式,Backdrop 组件会在您的应用中显示一个暗淡的图层。
<Button variant="outlined" color="primary" onClick={handleToggle}>
Show backdrop
</Button>
<Backdrop className={classes.backdrop} open={open} onClick={handleClose}>
<CircularProgress color="inherit" />
</Backdrop>