班级测验：底部按钮显示有问题

app/models/exercise.rb

@@ -8,15 +8,25 @@ class Exercise < ActiveRecord::Base
   has_many :users, :through => :exercise_users #该测试被哪些用户提交答案过
   # 课程消息
   has_many :course_messages, :class_name =>'CourseMessage', :as => :course_message, :dependent => :destroy
-  after_create :acts_as_course_message
+  after_save :acts_as_course_message
   def acts_as_course_message
     if self.course
-      if self.exercise_status == 2 #未发布
+      if self.exercise_status == 2 && self.course_messages.where(:status => 2).blank? #已发布
+        self.delay.send_exercise_message_delay
         #self.course.members.each do |m|
-          self.course_messages << CourseMessage.create(:user_id => User.current.id, :course_id => self.course_id, :viewed => false,:status=>2)
+          #self.course_messages << CourseMessage.create(:user_id => User.current.id, :course_id => self.course_id, :viewed => false,:status=>2)
         #end
-      # else
-      #   self.course_messages.destroy_all 这里的destory_all值得商榷。因为我这里是通过status来控制不同的status的
+      else
+        #self.course_messages.destroy_all #这里的destory_all值得商榷。因为我这里是通过status来控制不同的status的
+      end
+    end
+  end
+
+  #测验通知delay
+  def send_exercise_message_delay
+    self.course.members.each do |m|
+      if m.user_id != self.user_id
+        self.course_messages << CourseMessage.new(:user_id => m.user_id, :course_id => self.course_id, :viewed => false ,:status=>2)
       end
     end
   end

app/views/exercise/_exercise_teacher.html.erb

@@ -153,7 +153,7 @@
       <%= render :partial => 'exercise/total_questions_score', :locals => {:exercise => exercise, :current_score => current_score} %>
     </div>
 
-    <div class="ur_buttons" style="width: 297px;">
+    <div class="ur_buttons" style="width: 298px;">
       <%= link_to "返回", exercise_index_path(:course_id => @course.id),:class => "btn_grey_64_width" %>
       <a href="javascript:void(0)" onclick="send_exercise_to_course();" class="btn_green_64_width ml10 mr10">发送</a>
       <% if exercise.exercise_status == 1 %>