NullReferenceException when use Office 365 API in Xamarin.IOS

问题

First I got this issue: Using Office 365 API in Xamarin.Android

Now testing the same in Xamarin IOS I got another :(

{System.NullReferenceException: Object reference not set to an instance of an object
  at Microsoft.Office365.OAuth.Authenticator.GetRefreshToken (System.String resource) [0x00000] in <filename unknown>:0 
  at Microsoft.Office365.OAuth.Authenticator+<GetAuthenticationResult>d__c.MoveNext () [0x00000] in <filename unknown>:0 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000b] in /Developer/MonoTouch/Source/mono/mcs/class/corlib/System.Runtime.ExceptionServices/ExceptionDispatchInfo.cs:62 
  at System.Runtime.CompilerServices.TaskAwaiter`1[Microsoft.Office365.OAuth.AuthenticationInfo].GetResult () [0x00034] in /Developer/MonoTouch/Source/mono/mcs/class/corlib/System.Runtime.CompilerServices/TaskAwaiter_T.cs:59 
  at Microsoft.Office365.OAuth.Authenticator+<AuthenticateAsync>d__6.MoveNext () [0x00000] in <filename unknown>:0 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000b] in /Developer/MonoTouch/Source/mono/mcs/class/corlib/System.Runtime.ExceptionServices/ExceptionDispatchInfo.cs:62 
  at System.Runtime.CompilerServices.TaskAwaiter`1[Microsoft.Office365.OAuth.AuthenticationInfo].GetResult () [0x00034] in /Developer/MonoTouch/Source/mono/mcs/class/corlib/System.Runtime.CompilerServices/TaskAwaiter_T.cs:59 
  at Office365InXamarinApps.ViewModel.ContactsViewModel+<EnsureClientCreated>d__9.MoveNext () [0x00046] in c:\DevApps\GitHub\Office365InXamarinApps\scr\Office365InXamarinApps\Office365InXamarinApps\ViewModel\ContactsViewModel.cs:76 }

The code is here: https://github.com/saramgsilva/Office365InXamarinApp

回答1:

The Office 365 API Preview has issues and I cannot use it, for this reason I created another demo using Office 365 REST API.

https://github.com/saramgsilva/Office365RESTAPISample

回答2:

You may want to check out this blog post (see link in Xamarin Forum) -Xamarin developer was able to get it working in Android

http://forums.xamarin.com/discussion/21367/put-some-office-365-in-your-apps

来源：https://stackoverflow.com/questions/24541318/nullreferenceexception-when-use-office-365-api-in-xamarin-ios