wp_dashboard_quota

wp_dashboard_quota：此钩子用于向WordPress仪表盘添加配额指示器，显示站点媒体库的当前使用情况和可用空间。此挂钩可用于向配额指示器添加自定义功能或样式。

在仪表盘上显示文件上传配额。

在wp_dashboard_right_now()的{@see ‘activity_box_end’}挂钩上运行。

function wp_dashboard_quota() {
	if ( ! is_multisite() || ! current_user_can( 'upload_files' )
		|| get_site_option( 'upload_space_check_disabled' )
	) {
		return true;
	}

	$quota = get_space_allowed();
	$used  = get_space_used();

	if ( $used > $quota ) {
		$percentused = '100';
	} else {
		$percentused = ( $used / $quota ) * 100;
	}

	$used_class  = ( $percentused >= 70 ) ? ' warning' : '';
	$used        = round( $used, 2 );
	$percentused = number_format( $percentused );

	?>
	<h3 class="mu-storage"><?php _e( 'Storage Space' ); ?></h3>
	<div class="mu-storage">
	<ul>
		<li class="storage-count">
			<?php
			$text = sprintf(
				/* translators: %s: Number of megabytes. */
				__( '%s MB Space Allowed' ),
				number_format_i18n( $quota )
			);
			printf(
				'<a href="%1$s">%2$s <span class="screen-reader-text">(%3$s)</span></a>',
				esc_url( admin_url( 'upload.php' ) ),
				$text,
				__( 'Manage Uploads' )
			);
			?>
		</li><li class="storage-count <?php echo $used_class; ?>">
			<?php
			$text = sprintf(
				/* translators: 1: Number of megabytes, 2: Percentage. */
				__( '%1$s MB (%2$s%%) Space Used' ),
				number_format_i18n( $used, 2 ),
				$percentused
			);
			printf(
				'<a href="%1$s" class="musublink">%2$s <span class="screen-reader-text">(%3$s)</span></a>',
				esc_url( admin_url( 'upload.php' ) ),
				$text,
				__( 'Manage Uploads' )
			);
			?>
		</li>
	</ul>
	</div>
	<?php
}