我不知道我做错了什么，但每次我试图获取令牌（当然是在用户身份验证之后），结果总是无效的grant_type参数或参数丢失
可能与Box API always returns invalid grant_type parameter on obtaining access token有关
以下是我的Fiddler结果：

POST https://api.box.com/oauth2/token HTTP/1.1
Host: api.box.com
Content-Length: 157
Expect: 100-continue
Connection: Keep-Alive

grant_type=authorization_code&code=nnqtYcoik7cjtHQYyn3Af8uk4LG3rYYh&client_id=[myclientId]&client_secret=[mysecret]

测试结果：

HTTP/1.1 400 Bad Request
Server: nginx
Date: Thu, 07 Mar 2013 11:18:36 GMT
Content-Type: application/json
Connection: keep-alive
Set-Cookie: box_visitor_id=5138778bf12a01.27393131; expires=Fri, 07-Mar-2014 11:18:35 GMT; path=/; domain=.box.com
Set-Cookie: country_code=US; expires=Mon, 06-May-2013 11:18:36 GMT; path=/
Cache-Control: no-store
Content-Length: 99

{"error":"invalid_request","error_description":"Invalid grant_type parameter or parameter missing"}

即使遵循curl示例也会产生相同的错误。如果你能帮忙的话，我将不胜感激。
编辑：尝试使用额外的redirect_uri参数，但仍然错误

POST https://api.box.com/oauth2/token HTTP/1.1
Content-Type: application/json; charset=UTF-8
Host: api.box.com
Content-Length: 187
Expect: 100-continue
Connection: Keep-Alive

grant_type=authorization_code&code=R3JxS7UPm8Gjc0y7YLj9qxifdzBYzLOZ&client_id=*****&client_secret=*****&redirect_uri=http://localhost

测试结果：

HTTP/1.1 400 Bad Request
Server: nginx
Date: Sat, 09 Mar 2013 00:46:38 GMT
Content-Type: application/json
Connection: keep-alive
Set-Cookie: box_visitor_id=513a866ec5cfe0.48604831; expires=Sun, 09-Mar-2014 00:46:38 GMT; path=/; domain=.box.com
Set-Cookie: country_code=US; expires=Wed, 08-May-2013 00:46:38 GMT; path=/
Cache-Control: no-store
Content-Length: 99

{"error":"invalid_request","error_description":"Invalid grant_type parameter or parameter missing"}