Ios Swift AFPOST错误

我得到以下错误。我的XCode版本7.1

/Users/chamath/Desktop/SwiftNvoi/Mobile/Mobile/APISFAuthentication.swift:30:22:无法将类型为“（AFHTTPRequestOperation！，NSError！）->（）”的值转换为预期的参数类型“（（AFHTTPRequestOperation？，NSError）->Void）？”

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在块中填充参数时，不需要指定类类型。如下所示更新参数：

func fAuthenticateUser(userEmail: String) -> String {

          let manager = AFHTTPRequestOperationManager()
        let postData = ["grant_type":"password","client_id":APISessionInfo.SF_CLIENT_ID,"client_secret":APISessionInfo.SF_CLIENT_SECRET,"username":APISessionInfo.SF_GUEST_USER,"password":APISessionInfo.SF_GUEST_USER_PASSWORD]

        manager.POST(APISessionInfo.SF_APP_URL,
            parameters: postData,
            success: { (operation, responseObject) in
                print("JSON: " + responseObject.description)
            },
            failure: { (operation, error) in
                print("Error: " + error.localizedDescription)
        })

    }

---

在块中填充参数时，不需要指定类类型。如下所示更新参数：

func fAuthenticateUser(userEmail: String) -> String {

          let manager = AFHTTPRequestOperationManager()
        let postData = ["grant_type":"password","client_id":APISessionInfo.SF_CLIENT_ID,"client_secret":APISessionInfo.SF_CLIENT_SECRET,"username":APISessionInfo.SF_GUEST_USER,"password":APISessionInfo.SF_GUEST_USER_PASSWORD]

        manager.POST(APISessionInfo.SF_APP_URL,
            parameters: postData,
            success: { (operation, responseObject) in
                print("JSON: " + responseObject.description)
            },
            failure: { (operation, error) in
                print("Error: " + error.localizedDescription)
        })

    }

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如何在NSData或NSArray中存储responseObject？如何在NSData或NSArray中存储responseObject？