Corrects the group management samples for C#

Gimly · web-flow · commit 7d5c89d11905 · 2019-07-04T16:11:47.000+02:00
The samples for the group management were not working, the `string userId` could not be bound correctly. By passing a `ClaimsPrincipal` we can correctly get the claims the user has used call the method, and therefore we can get its `UserId`. Fixes #34409
diff --git a/articles/azure-functions/functions-bindings-signalr-service.md b/articles/azure-functions/functions-bindings-signalr-service.md
@@ -276,14 +276,15 @@ The following example adds a user to a group.
 [FunctionName("addToGroup")]
 public static Task AddToGroup(
     [HttpTrigger(AuthorizationLevel.Anonymous, "post")]HttpRequest req,
-    string userId,
+    ClaimsPrincipal claimsPrincipal,
     [SignalR(HubName = "chat")]
         IAsyncCollector<SignalRGroupAction> signalRGroupActions)
 {
+    var userIdClaim = claimsPrincipal.FindFirst(ClaimTypes.NameIdentifier);
     return signalRGroupActions.AddAsync(
         new SignalRGroupAction
         {
-            UserId = userId,
+            UserId = userIdClaim.Value,
             GroupName = "myGroup",
             Action = GroupAction.Add
         });
@@ -298,20 +299,24 @@ The following example removes a user from a group.
 [FunctionName("removeFromGroup")]
 public static Task RemoveFromGroup(
     [HttpTrigger(AuthorizationLevel.Anonymous, "post")]HttpRequest req,
-    string userId,
+    ClaimsPrincipal claimsPrincipal,
     [SignalR(HubName = "chat")]
         IAsyncCollector<SignalRGroupAction> signalRGroupActions)
 {
+    var userIdClaim = claimsPrincipal.FindFirst(ClaimTypes.NameIdentifier);
     return signalRGroupActions.AddAsync(
         new SignalRGroupAction
         {
-            UserId = userId,
+            UserId = userIdClaim.Value,
             GroupName = "myGroup",
             Action = GroupAction.Remove
         });
 }
 ```
 
+> [!NOTE]
+> In order to get the `ClaimsPrincipal` correctly bound, you must have configured the authentication settings in Azure Functions.
+
 ### 2.x JavaScript send message output examples
 
 #### Broadcast to all clients
