text: import React from 'react';
  import { Grid, Typography, CircularProgress } from '@material-ui/core';
  
  const Loading = ({ showTitle, title }) => {
    return (
      <Grid
        container
        justify="center"
        alignItems="center"
        style={{ height: '80%' }}
      >
        <Grid item container alignItems="center" direction="column" spacing={8}>
          {showTitle && (
            <Grid item>
              <Typography color="textSecondary" variant="h4" align="center">
                {title}
              </Typography>
            </Grid>
          )}
          <Grid item>
            <CircularProgress style={{ color: 'rgba(0, 0, 0, 0.54)' }} />
          </Grid>
        </Grid>
      </Grid>
    );
  };
  
  Loading.defaultProps = {
    showTitle: true,
    title: '正在加载'
  };
  
  export default Loading;
  