[#20] MemberAdminWindow: Add MemberBusinessSharesAdminWindow to manage member shares

Elwig/Windows/DeliveryAdminWindow.xaml.cs

@@ -124,7 +124,8 @@ namespace Elwig.Windows {
 
         public DeliveryAdminWindow(int mgnr) :
             this() {
-            ViewModel.FilterMember = DeliveryService.GetMember(mgnr) ?? throw new ArgumentException("MgNr argument has invalid value");
+            using var ctx = new AppDbContext();
+            ViewModel.FilterMember = ctx.Members.Find(mgnr) ?? throw new ArgumentException("MgNr argument has invalid value");
             ViewModel.Title = $"Lieferungen - {ViewModel.FilterMember.AdministrativeName} - Elwig";
             ViewModel.EnableAllSeasons = true;
         }
@@ -482,7 +483,7 @@ namespace Elwig.Windows {
             await base.OnRenewContext(ctx);
 
             if (ViewModel.FilterMember != null) {
-                if (await DeliveryService.GetMemberAsync(ViewModel.FilterMember.MgNr) is not Member m) {
+                if (await ctx.FetchMembers(ViewModel.FilterMember.MgNr).SingleOrDefaultAsync() is not Member m) {
                     Close();
                     return;
                 }
@@ -1200,7 +1201,7 @@ namespace Elwig.Windows {
         }
 
         private async Task UpdateLsNr() {
-            if (string.IsNullOrEmpty(ViewModel.Date) || ViewModel.Branch == null) {
+            if (string.IsNullOrWhiteSpace(ViewModel.Date) || ViewModel.Branch == null) {
                 ViewModel.LsNr = "";
             } else {
                 try {