调整

app/helpers/application_helper.rb

@@ -4381,7 +4381,7 @@ module ApplicationHelper
       elsif  attachment.container_type == "Bid" && attachment.container && attachment.container.courses
         course = attachment.container.courses.first
         candown = User.current.member_of_course?(attachment.container.courses.first) || (course.is_public == 1 && attachment.is_public == 1)
-      elsif attachment.container_type == "Library" || attachment.container.class.to_s == "Library" #教学案例允许下载
+      elsif attachment.container_type == "Library" #教学案例允许下载
         candown = true
       elsif attachment.container_type == "ProjectPackage" #教学案例允许下载
         candown = true

app/views/libraries/_library_list.html.erb

@@ -2,7 +2,7 @@
   <% if @libraries.present? %>
     <% @libraries.each do |library| %>
       <li class="library_list_item">
-        <% image_url = library.cover.present? ? named_attachment_path(library.cover.id, library.cover.filename) : 'educoder/library-default-cover.png' %>
+        <% image_url = library.cover.present? ? download_attachment_path(library.cover.id) : 'educoder/library-default-cover.png' %>
         <%= image_tag(image_url, width: 120, height: 90, class: 'mr15 mt3 radius4') %>
         <div class="flex1">
           <p class="clearfix mb15 lineh-40 mt10">