我们正在尝试使用Xamarin编写iOS应用程序，该应用程序通过使用azure广告保护我们的rest api进行身份验证。在我们的案例中，该应用程序将部署到企业iOS设备上，并且需要在一年中的一天运行大约8小时。 app / api不需要知道登录的用户，因此该应用程序将更多地作为守护程序应用程序而不是本机应用程序运行。下面的代码给出了一个对象引用异常，我也包含了下面的堆栈跟踪。我们能够在输入用户凭据时对服务进行身份验证，但鉴于我们的部署环境，这并不理想。
我的问题是：Xamarin iOS上的ADAL不支持此身份验证方法吗？如果是这样，我们可以使用另一个身份验证库来完成此任务吗？或者我们是否通过尝试以这种方式进行身份验证来游泳？
static async void LoadService()
{
try
{
string aadInstance = "https://login.microsoftonline.com/{0}";
string tenant = "ourname.onmicrosoft.com";
string clientId = "our client id";
string appKey = "our app key";
string authority = string.Format(CultureInfo.InvariantCulture, aadInstance, tenant);
string resourceId = "https://ourname.onmicrosoft.com/TheService";
AuthenticationContext authContext = new AuthenticationContext(authority);
ClientCredential clientCredential = new ClientCredential(clientId, appKey);
AuthenticationResult result = await authContext.AcquireTokenAsync(resourceId, clientCredential);
HttpClient client = new HttpClient();
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", result.AccessToken);
}
catch (Exception ex)
{
ex.ToString();
}
}
错误堆栈跟踪：
at Microsoft.IdentityModel.Clients.ActiveDirectory.BrokerHelper.get_CanInvokeBroker () [0x0000c] in <filename unknown>:0
at Microsoft.IdentityModel.Clients.ActiveDirectory.AcquireTokenHandlerBase+<RunAsync>d__54.MoveNext () [0x0027d] in <filename unknown>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Users/builder/data/lanes/3051/5f11db87/source/maccore/_build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/external/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /Users/builder/data/lanes/3051/5f11db87/source/maccore/_build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:201
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /Users/builder/data/lanes/3051/5f11db87/source/maccore/_build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:170
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /Users/builder/data/lanes/3051/5f11db87/source/maccore/_build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:142
at System.Runtime.CompilerServices.TaskAwaiter`1[TResult].GetResult () [0x00000] in /Users/builder/data/lanes/3051/5f11db87/source/maccore/_build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:372
at Microsoft.IdentityModel.Clients.ActiveDirectory.AuthenticationContext+<AcquireTokenForClientCommonAsync>d__45.MoveNext () [0x00081] in <filename unknown>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Users/builder/data/lanes/3051/5f11db87/source/maccore/_build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/external/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /Users/builder/data/lanes/3051/5f11db87/source/maccore/_build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:201
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /Users/builder/data/lanes/3051/5f11db87/source/maccore/_build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:170
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /Users/builder/data/lanes/3051/5f11db87/source/maccore/_build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:142
at System.Runtime.CompilerServices.TaskAwaiter`1[TResult].GetResult () [0x00000] in /Users/builder/data/lanes/3051/5f11db87/source/maccore/_build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:372
at Microsoft.IdentityModel.Clients.ActiveDirectory.AuthenticationContext+<AcquireTokenAsync>d__22.MoveNext () [0x00071] in <filename unknown>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Users/builder/data/lanes/3051/5f11db87/source/maccore/_build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/external/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /Users/builder/data/lanes/3051/5f11db87/source/maccore/_build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:201
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /Users/builder/data/lanes/3051/5f11db87/source/maccore/_build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:170
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /Users/builder/data/lanes/3051/5f11db87/source/maccore/_build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:142
at System.Runtime.CompilerServices.TaskAwaiter`1[TResult].GetResult () [0x00000] in /Users/builder/data/lanes/3051/5f11db87/source/maccore/_build/Library/Frameworks/Xamarin.iOS.framework/Versions/git/src/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:372
at App1.ViewController+<LoadService>d__3.MoveNext () [0x000c7] in C:\Users\brians\Documents\Visual Studio 2015\Projects\App2\App1\ViewController.cs:52