bbp_get_forum_thumbnail_src (forum_id美元＝零，美元的大小＝零，美元的类型＝零）

Function bbp_get_forum_thumbnail_src($forum_id = null， $size = null， $type = null) {if ($thumbnail_id = get_post_thumbnail_id($forum_id)) {return wp_get_attachment_image_url($thumbnail_id， $size);} if ($group_id = bbp_get_forum_group_ids($forum_id)) {$group_id = $group_ids[0];$group_avatar_url = bp_core_fetch_avatar(['item_id' => $group_id， 'object' => 'group'， 'type' => $type， 'html' => false， 'force_default' => false，]);$group_default_avatar = bp_group_default_avatar ("， ['object' => 'group'， 'type' => $type]); / /指定用户类型If ($group_avatar_url != $group_default_avatar){返回$group_avatar_url;}}返回";｝