我如何检查缩略图YouTube API

Question

我尝试检查是否不存在maxres，请显示标准等等，但如果找不到maxres，则找不到任何URL，为什么？

$thumbnails = $vid["items"][0]["snippet"]["thumbnails"]["maxres"]["url"];
  if($thumbnails == ""){
    $thumbnails = $vid["items"][0]["snippet"]["thumbnails"]["standard"]["url"];
  }elseif($thumbnails == ""){
    $thumbnails = $vid["items"][0]["snippet"]["thumbnails"]["high"]["url"];
  }elseif($thumbnails == ""){
    $thumbnails = $vid["items"][0]["snippet"]["thumbnails"]["medium"]["url"];
  }elseif($thumbnails == ""){
    $thumbnails = $vid["items"][0]["snippet"]["thumbnails"]["default"]["url"];
  }

Answer 1

所以我注意到您的脚本的几个问题是您的主要问题是您的if语句将输入第一个循环，如果失败将永远不会输入另一个循环

我已经在服务器上测试了以下脚本，发现它正在工作，我希望您对您很清楚，如果不是，我留下了评论

<?php
function GetData($url,$post){
    $ch = curl_init($url . $post);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    $response = curl_exec($ch);
    curl_close($ch);
    return $response;
}
$res = GetData("https://www.googleapis.com/youtube/v3/videos?","part=snippet&id=<video_id>&key=<your_key>");
$result = json_decode($res);
//Check for maxres thumb
$maxresThumb = $result->items[0]->snippet->thumbnails->maxres->url;
$thumbnail = '';
if($maxresThumb == '' || $maxresThumb == null){
  //if maxresThumb is not existent check for high res
  $highThumb = $result->items[0]->snippet->thumbnails->high->url;
  if($highThumb == '' || $highThumb == null){
    //Check for standard thumb
    $standardThumb = $result->items[0]->snippet->thumbnails->standard->url;
    if($standardThumb == '' || $standardThumb == null){
      //CHeck for next thumb....
    }else{
      $thumbnail = $standardThumb;
    }
  }else{
    $thumbnail = $highThumb;
  }
}else{
  $thumbnail = $maxResThumb;
}
?>

Answer 2

现在正在工作，我更改为

$thumbnails = $vid["items"][0]["snippet"]["thumbnails"]["maxres"]["url"];
  if($thumbnails == "" || $thumbnails == null){
    $thumbnails = $vid["items"][0]["snippet"]["thumbnails"]["standard"]["url"];
    if($thumbnails == "" || $thumbnails == null){
      $thumbnails = $vid["items"][0]["snippet"]["thumbnails"]["high"]["url"];
      if($thumbnails == "" || $thumbnails == null){
        $thumbnails = $vid["items"][0]["snippet"]["thumbnails"]["medium"]["url"];
        if($thumbnails == "" || $thumbnails == null){
          $thumbnails = $vid["items"][0]["snippet"]["thumbnails"]["default"]["url"];
        }
      }
    }
  }