Fix design mode model selection (incorrectly using design model in tests)

Author: webprofusion-chrisc

src/Certify.UI.Shared/ViewModel/AppViewModel/AppViewModel.cs

@@ -1,7 +1,7 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Diagnostics;
+using System.ComponentModel;
 using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
@@ -53,14 +53,13 @@ public AppViewModel(ICertifyClient certifyClient)
         /// <returns></returns>
         public static AppViewModel GetModel()
         {
-            var stack = new StackTrace();
-            if (stack.GetFrames().Last().GetMethod().Name == "Main")
+            if (DesignerProperties.GetIsInDesignMode(new DependencyObject()))
             {
-                return new AppViewModel();
+                return new AppViewModelDesign();
             }
             else
             {
-                return new AppViewModelDesign();
+                return new AppViewModel();
             }
         }
 

src/Certify.UI.Shared/ViewModel/ManagedCertificateViewModel.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
+using System.ComponentModel;
 using System.Linq;
 using System.Threading.Tasks;
 using System.Windows;
@@ -19,7 +20,6 @@ public class ManagedCertificateViewModel : BindableBase
         /// <summary>
         /// Provide single static instance of model for all consumers 
         /// </summary>
-        //public static AppModel AppViewModel = new DesignViewModel(); // for UI testing
         public static ManagedCertificateViewModel Current = ManagedCertificateViewModel.GetModel();
 
         private Certify.UI.ViewModel.AppViewModel _appViewModel => ViewModel.AppViewModel.Current;
@@ -449,14 +449,13 @@ public int? PercentageLifetimeElapsed
 
         public static ManagedCertificateViewModel GetModel()
         {
-            var stack = new System.Diagnostics.StackTrace();
-            if (stack.GetFrames().Last().GetMethod().Name == "Main")
+            if (DesignerProperties.GetIsInDesignMode(new DependencyObject()))
             {
-                return new ManagedCertificateViewModel();
+                return new ManagedCertificateViewModelDesign();
             }
             else
             {
-                return new ManagedCertificateViewModelDesign();
+                return new ManagedCertificateViewModel();
             }
         }