Retrieves an external feed and parses it. Uses the SimplePie and FeedCache functionality for retrieval and parsing and automatic caching.
<?php $feed = fetch_feed( $uri ); ?>
(mixed) (必填) The URI of the RSS feed you want to retrieve. If an array of URIs, the feeds are merged using SimplePie's multifeed feature. The resulting feed is returned as a standard SimplePie object.
fetch_feed caches results for 12 hours by default. You can modify this by modifying the time interval via the 过滤器 wp_feed_cache_transient_lifetime.