在你得到它的ID（get_post_thumbnail_id($YOUR_POST_ID) ) 您需要知道上传的基本url和附件元数据。

Uploads base url 可以在返回的数组中找到wp_upload_dir().

Attachment meta data 可通过检索wp_get_attachment_metadata().

下面是我编写的一个方便的函数，它为any image attachment, not just featured.

function prepareImageData( $attachment_id ){
  $uploads_baseurl = wp_upload_dir()[\'baseurl\'];

  $prepared = [];
  $data = wp_get_attachment_metadata($attachment_id);
  $prepared = [
    \'mime_type\' => get_post_mime_type($attachment_id),
    \'url\' => $uploads_baseurl.\'/\'.$data[\'file\'],
    \'sizes\' => [],
  ];

  foreach( $data[\'sizes\'] as $size => $sizeInfo ){
    $prepared[\'sizes\'][$size] = [
      \'url\' => $uploads_baseurl.\'/\'.$sizeInfo[\'file\'],
    ];
  }

  return $prepared;
}

要根据大小获取图像，可以使用wordpres预定义函数，即the_post_thumbnail( $size, $attr ).

您可以使用预定义的媒体大小。

the_post_thumbnail();                 

the_post_thumbnail( \'thumbnail\' );       // Thumbnail (default 150px x 150px max)
the_post_thumbnail( \'medium\' );          // Medium resolution (default 300px x 300px max)
the_post_thumbnail( \'large\' );           // Large resolution (default 640px x 640px max)
the_post_thumbnail( \'full\' );            // Full resolution (original size uploaded)

the_post_thumbnail( array(100, 100) );