How to get a YouTube thumbnail from a YouTube iframe?

后端未结
关注
 3  676
暗喜 2021-01-30 09:00
For instance I have a blog post that has the following iframe.
</script>
<ins class="adsbygoogle"
     style="display:block"
     data-ad-client="ca-pub-5408099190056760"
     data-ad-slot="7305827575"
     data-ad-format="auto"
     data-full-width-responsive="true"></ins>
<script>
     (adsbygoogle = window.adsbygoogle || []).push({});
</script>        </div>
      </div>
      
      <div class="fly-panel detail-box" id="flyReply">
        <fieldset class="layui-elem-field layui-field-title" style="text-align: center;">
          <legend>3条回答</legend>        </fieldset>

        <ul class="jieda" id="jieda">
                    <li data-id="111" class="jieda-daan">
            <a name="item-1111111111"></a>
            <div class="detail-about detail-about-reply">
                         <a class="fly-avatar" href="">
                <img src="https://www.e-learn.cn/qa/data/avatar/000/00/01/small_000000116.jpg" alt=" 孤城傲影 ">
              </a>
              <div class="fly-detail-user">
                <a href="" class="fly-link">
                  <cite> 孤城傲影</cite>
                                             
                </a>
                
                <span>(楼主)</span>
            
              </div>              <div class="detail-hits">
                <span>2021-01-30 09:22</span>
              </div>

            </div>
            <div class="detail-body jieda-body photos">
              <p>          
<p>This function work with all types of youtube links & domains such as <br />
https://www.youtube.com/watch?v=WZKW2Hq2fks</p>
<p>https://youtu.be/WZKW2Hq2fks</p>
<p>https://www.youtube.com/embed/WZKW2Hq2fks </p>
<p>https://youtu.be/WZKW2Hq2fks?t=66</p>
<p>And you can get the quality you want.</p>
<p>To use it:</p>
<pre><code>// quality options: low, medium, high, max | default is max.
var thumbnail = get_youtube_thumbnail('https://youtu.be/WZKW2Hq2fks', 'max');
console.log(thumbnail);
</code></pre>
<hr />
<pre><code>function get_youtube_thumbnail(url, quality){
    if(url){
        var video_id, thumbnail, result;
        if(result = url.match(/youtube\.com.*(\?v=|\/embed\/)(.{11})/))
        {
            video_id = result.pop();
        }
        else if(result = url.match(/youtu.be\/(.{11})/))
        {
            video_id = result.pop();
        }

        if(video_id){
            if(typeof quality == "undefined"){
                quality = 'high';
            }
        
            var quality_key = 'maxresdefault'; // Max quality
            if(quality == 'low'){
                quality_key = 'sddefault';
            }else if(quality == 'medium'){
                quality_key = 'mqdefault';
            } else if (quality == 'high') {
                quality_key = 'hqdefault';
            }

            var thumbnail = "http://img.youtube.com/vi/"+video_id+"/"+quality_key+".jpg";
            return thumbnail;
        }
    }
    return false;
}
</code></pre>
    </p>
             <div class="appendcontent">
                                                        </div>
            </div>
            <div class="jieda-reply">
              <span class="jieda-zan button_agree" type="zan" data-id='1938608'>
                <i class="iconfont icon-zan"></i>
                <em>0</em>
              </span>
                   <span type="reply" class="showpinglun" data-id="1938608">
                <i class="iconfont icon-svgmoban53"></i>
               讨论(0)
              </span>
                                                  
              
              <div class="jieda-admin">
                          
             
       
          
              </div>
                                       <div class="noreplaytext bb">
<center><div>   <a href="https://www.e-learn.cn/qa/q-946232.html">  查看其它3个回答
</a>
</div></center>
</div>            </div>
                         <div class="comments-mod "  style="display: none; float:none;padding-top:10px;" id="comment_1938608">
                    <div class="areabox clearfix">

<form class="layui-form" action="">
               
            <div class="layui-form-item">
    <label class="layui-form-label" style="padding-left:0px;width:60px;">发布评论:</label>
    <div class="layui-input-block" style="margin-left:90px;">
         <input type="text" placeholder="不少于5个字" AUTOCOMPLETE="off" class="comment-input layui-input" name="content" />
                        <input type='hidden' value='0' name='replyauthor' />
    </div>
    <div class="mar-t10"><span class="fr layui-btn layui-btn-sm addhuidapinglun" data-id="1938608">提交评论 </span></div>
  </div>
  
</form>
                    </div>
                    <hr>
                    <ul class="my-comments-list nav">
                        <li class="loading">
                        <img src='https://www.e-learn.cn/qa/static/css/default/loading.gif' align='absmiddle' />
                        &nbsp;加载中...
                        </li>
                    </ul>
                </div>
          </li>
                              			
        </ul>
        
        <div class="layui-form layui-form-pane">
          <form id="huidaform"  name="answerForm"  method="post">
            
            <div class="layui-form-item layui-form-text">
              <a name="comment"></a>
              <div class="layui-input-block">
            
    
<script type="text/javascript" src="https://www.e-learn.cn/qa/static/js/neweditor/ueditor.config.js"></script>
<script type="text/javascript" src="https://www.e-learn.cn/qa/static/js/neweditor/ueditor.all.js"></script>
<script type="text/plain" id="editor"  name="content"  style="width:100%;height:200px;"></script>                                 
<script type="text/javascript">
                                 var isueditor=1;
            var editor = UE.getEditor('editor',{
                //这里可以选择自己需要的工具按钮名称,此处仅选择如下五个
                toolbars:[['source','fullscreen',  '|', 'undo', 'redo', '|', 'bold', 'italic', 'underline', 'fontborder', 'strikethrough', 'removeformat', 'formatmatch', 'autotypeset', 'blockquote', 'pasteplain', '|', 'forecolor', 'backcolor', 'insertorderedlist', 'insertunorderedlist', 'selectall', 'cleardoc', '|', 'rowspacingtop', 'rowspacingbottom', 'lineheight', '|', 'customstyle', 'paragraph', 'fontfamily', 'fontsize', '|', 'indent', '|', 'justifyleft', 'justifycenter', 'justifyright', 'justifyjustify', '|', 'link', 'unlink', 'anchor', '|', 'simpleupload', 'insertimage', 'scrawl', 'insertvideo', 'attachment', 'map', 'insertcode', '|', 'horizontal', '|', 'preview', 'searchreplace', 'drafts']],
            
                initialContent:'',
                //关闭字数统计
                wordCount:false,
                zIndex:2,
                //关闭elementPath
                elementPathEnabled:false,
                //默认的编辑区域高度
                initialFrameHeight:250
                //更多其他参数，请参考ueditor.config.js中的配置项
                //更多其他参数，请参考ueditor.config.js中的配置项
            });
                        editor.ready(function() {
            	editor.setDisabled();
            	});
                            $("#editor").find("*").css("max-width","362px");
        </script>              </div>
            </div>
                          
    

        
         <div class="layui-form-item">
                <label for="L_vercode" class="layui-form-label">验证码</label>
                <div class="layui-input-inline">
                  <input type="text"  id="code" name="code"   value="" required lay-verify="required" placeholder="图片验证码" autocomplete="off" class="layui-input">
                </div>
                <div class="layui-form-mid">
                  <span style="color: #c00;"><img class="hand" src="https://www.e-learn.cn/qa/user/code.html" onclick="javascript:updatecode();" id="verifycode"><a class="changecode"  href="javascript:updatecode();">&nbsp;看不清?</a></span>
                </div>
              </div>
                                  <div class="layui-form-item">
                    <input type="hidden" value="946232" id="ans_qid" name="qid">
   <input type="hidden" id="tokenkey" name="tokenkey" value=''/>
                <input type="hidden" value="How to get a YouTube thumbnail from a YouTube iframe?" id="ans_title" name="title"> 
             
              <div class="layui-btn    layui-btn-disabled"  id="ajaxsubmitasnwer" >提交回复</div>
            </div>
          </form>
        </div>
      </div>
      <input type="hidden" value="946232" id="adopt_qid"	name="qid" /> 
      <input type="hidden" id="adopt_answer" value="0"	name="aid" />
    </div>
    <div class="layui-col-md4">
          
 <!-- 热门讨论问题 -->
     
 <dl class="fly-panel fly-list-one">
        <dt class="fly-panel-title">热议问题</dt>
            <!-- 本周热门讨论问题显示10条-->