如何使用gunicorn在heroku上提供django静态文件

settings.py

DEBUG = True
TEMPLATE_DEBUG = DEBUG
import os
PROJECT_PATH = os.path.abspath(os.path.dirname(__file__))
SITE_PATH = os.path.abspath(os.path.join(PROJECT_PATH,os.path.pardir))

STATIC_ROOT = ''
STATIC_URL = '/static/'
STATICFILES_DIRS = (
    os.path.join(SITE_PATH,'staticfiles'),)
STATICFILES_FINDERS = (
    'django.contrib.staticfiles.finders.FileSystemFinder','django.contrib.staticfiles.finders.AppDirectoriesFinder',#    'django.contrib.staticfiles.finders.DefaultStorageFinder',)

urls.py

from django.conf import settings
from django.conf.urls import patterns,include,url
from polls.views import VoteClassBasedView
from django.contrib import admin
admin.autodiscover()


urlpatterns = patterns('',url(r'^polls/',include('polls.urls')),url(r'^admin/',include(admin.site.urls)),)

Procfile

web: gunicorn django_polls.wsgi

我的本地目录结构

drwxrwxr-x 2 user1 user1  4096 Jul  5 11:48 django_polls/
-rwxr-xr-x 1 user1 user1   255 Jun 22 15:50 manage.py*
drwxrwxr-x 5 user1 user1  4096 Jul  3 14:41 polls/
-rw-r--r-- 1 user1 user1 50176 Jul  5 11:41 polls.db
-rw-rw-r-- 1 user1 user1    32 Jul  4 18:57 Procfile
-rw-rw-r-- 1 user1 user1   338 Jun 25 18:51 README.md
-rw-rw-r-- 1 user1 user1   310 Jul  4 17:09 requirements.txt
drwxrwxr-x 5 user1 user1  4096 Jul  4 17:57 staticfiles/
                                                         /bootstrap
                                                         /admin
                                                         /polls 
drwxrwxrwx 3 user1 user1  4096 Jun 22 18:59 templates/

Heroku文件结构

drwx------ 2 u19068 19068 4096 2013-07-05 11:31 django_polls/
-rwx------ 1 u19068 19068  255 2013-07-05 11:28 manage.py*
drwx------ 5 u19068 19068 4096 2013-07-05 11:31 polls/
-rw------- 1 u19068 19068   32 2013-07-05 11:28 Procfile
-rw------- 1 u19068 19068  338 2013-07-05 11:28 README.md
-rw------- 1 u19068 19068  310 2013-07-05 11:28 requirements.txt
-rw------- 1 u19068 19068   13 2013-07-05 11:28 runtime.txt
drwx------ 5 u19068 19068 4096 2013-07-05 11:28 staticfiles/
                                                          /bootstrap
                                                          /admin
                                                          /polls 
drwx------ 3 u19068 19068 4096 2013-07-05 11:28 templates/

上面的代码能够在本地机器上提供css文件(实际上我与bootstrap集成),但在将它提交到heroku git hub并运行类似polls.herokuapp.com/polls/之类的url后,它正在提供html文件和整个功能,但无法提供css文件.

此外,当我运行命令foreman start时,它也提供静态(css,js)文件,但是在heroku上部署时相同的代码无法为静态文件提供服务.

谁能告诉我需要在哪些文件中进行哪些更改才能在heroku上部署Django应用程序？

请注意,我已经完成了R& D并应用了各种代码,例如在urls.py中使用django.contrib.staticfiles.urls import staticfiles_urlpatterns但无法获得解决方案.