需求原因原版的Typecho不支持在线视频预览,只有一个图片预览功能，所以为了实现可以在线预览视频功能

修改 typecho/admin/media.php，在大概19行的时候,追加如下内容

       <?php if ($attachment->attachment->isImage): ?>
                <p><img src="<?php $attachment->attachment->url(); ?>"
                        alt="<?php $attachment->attachment->name(); ?>" class="typecho-attachment-photo"/></p>
            <?php endif; ?>
            
           <?php if ($attachment->attachment->mime == "video/mp4"): ?>
             <video src="<?php $attachment->attachment->url(); ?>" controls="true" height="320" ></video>
            <?php endif; ?>
 
           <?php if ($attachment->attachment->mime == "text/plain"): ?>
             <iframe src="<?php $attachment->attachment->url(); ?>" controls="true" width="100%" ></iframe>
            <?php endif; ?>
            
            <?php if ($attachment->attachment->mime == "application/pdf"): ?>
             <iframe src="<?php $attachment->attachment->url(); ?>" controls="true" width="100%" ></iframe>
            <?php endif; ?>