Catch exception precisely, and change an api url

Author: rayluo

tests/DevApps/WebAppCallsMicrosoftGraph/Pages/Index.cshtml.cs

@@ -29,30 +29,37 @@ public IndexModel(ILogger<IndexModel> logger, GraphServiceClient graphServiceCli
 
         public async Task OnGet()
         {
-            var user = await _graphServiceClient.Me.GetAsync(r => 
-            r.Options.WithScopes("user.read")
-            //.WithUser(User)
-            );
-         
+            try
+            {
+                var user = await _graphServiceClient.Me.GetAsync(r =>
+                r.Options.WithScopes("user.read")
+                //.WithUser(User)
+                );
+                ViewData["name"] = user.DisplayName;
+            }
+            catch (Exception)
+            {
+                ViewData["name"] = null;
+            }
+
             try
             {
                 using (var photoStream = await _graphServiceClient.Me.Photo.Content.GetAsync())
                 {
                     byte[] photoByte = ((MemoryStream)photoStream).ToArray();
                     ViewData["photo"] = Convert.ToBase64String(photoByte);
                 }
-                ViewData["name"] = user.DisplayName;
-
-                var graphData = await _downstreamApi.CallApiForUserAsync(
-                    "GraphBeta"
-                    );
-                ViewData["json"] = await graphData.Content.ReadAsStringAsync();
             }
             catch (Exception)
             {
                 ViewData["photo"] = null;
             }
 
+            var graphData = await _downstreamApi.CallApiForUserAsync(
+                "GraphBeta"
+                );
+            ViewData["json"] = await graphData.Content.ReadAsStringAsync();
+
             // Or - Call a downstream directly with the IDownstreamApi helper (uses the authorization header provider, encapsulates MSAL.NET)
             // See https://aka.ms/ms-id-web/downstream-web-api
             IDownstreamApi downstreamApi = HttpContext.RequestServices.GetService(typeof(IDownstreamApi)) as IDownstreamApi;
@@ -70,7 +77,7 @@ public async Task OnGet()
                 new AuthorizationHeaderProviderOptions { BaseUrl = "https://graph.microsoft.com/v1.0/me"} );
             HttpClient client = new HttpClient();
             client.DefaultRequestHeaders.Add("Authorization", authorizationHeader);
-            HttpResponseMessage response = await client.GetAsync("https://graph.microsoft.com/v1.0/users");
+            HttpResponseMessage response = await client.GetAsync("https://graph.microsoft.com/v1.0/me");
 
             // Or - Get a token if an SDK needs it (uses MSAL.NET)
             ITokenAcquirerFactory tokenAcquirerFactory = HttpContext.RequestServices.GetService(typeof(ITokenAcquirerFactory)) as ITokenAcquirerFactory;