编程作业结果显示问题

app/models/student_work_test.rb

@@ -1,12 +1,12 @@
 # encoding: utf-8
 class StudentWorkTest < ActiveRecord::Base
-  attr_accessible :student_work_id, :homework_test_id
+  attr_accessible :student_work_id, :homework_test_id, :result
 
   belongs_to :homework_test
   belongs_to :student_work
 
   def status_to_s
-    case self.result
+    case self.result.to_i
       when -1
         '编译出错'
       when -2
@@ -33,7 +33,7 @@ class StudentWorkTest < ActiveRecord::Base
   end
 
   def test_score
-    if self.result == 0
+    if self.result.to_i == 0
       format("%.1f",100.0 / self.student_work.homework_common.homework_tests.count)
     else
       0