ContextWindow: Add HasContextLoaded property

Elwig/Windows/MemberAdminWindow.xaml.cs

@@ -83,11 +83,8 @@ namespace Elwig.Windows {
             Menu_Export_UploadFilters.IsEnabled = App.Config.SyncUrl != null;
             Menu_Export_UploadAll.IsEnabled = App.Config.SyncUrl != null;
             ViewModel.ShowOnlyActiveMembers = true;
-        }
 
-        protected override async Task OnInit(AppDbContext ctx) {
             UpdateContactInfoVisibility();
-            LockInputs();
         }
 
         public void FocusMember(int mgnr) {
@@ -334,7 +331,7 @@ namespace Elwig.Windows {
         }
 
         private async void ActiveMemberInput_Changed(object sender, RoutedEventArgs evt) {
-            if (!IsInitialized) return;
+            if (!HasContextLoaded) return;
             await RefreshList();
         }
 
@@ -491,6 +488,7 @@ namespace Elwig.Windows {
         }
 
         private async void SearchInput_TextChanged(object sender, RoutedEventArgs evt) {
+            if (!HasContextLoaded) return;
             await RefreshList(true);
         }