stop double entry/click on dialog close commands fix #126

Author: ButchersBoy

MaterialDesignThemes.Wpf/DialogHost.cs

@@ -37,10 +37,10 @@ public class DialogHost : ContentControl
         private DialogClosingEventHandler _asyncShowClosingEventHandler;
 
         private Popup _popup;
-        private DialogSession _session;
         private DialogOpenedEventHandler _attachedDialogOpenedEventHandler;
         private DialogClosingEventHandler _attachedDialogClosingEventHandler;        
         private object _closeDialogExecutionParameter;
+        private DialogSession _session;
 
         static DialogHost()
         {
@@ -173,13 +173,13 @@ public static async Task<object> Show(object content, object dialogIndetifier, D
 
             return targets[0]._closeDialogExecutionParameter;
         }
-        
+
         public DialogHost()
         {
             Loaded += OnLoaded;
             Unloaded += OnUnloaded;
 
-            CommandBindings.Add(new CommandBinding(CloseDialogCommand, CloseDialogHandler));
+            CommandBindings.Add(new CommandBinding(CloseDialogCommand, CloseDialogHandler, CloseDialogCanExecute));
             CommandBindings.Add(new CommandBinding(OpenDialogCommand, OpenDialogHandler));
         }
 
@@ -458,6 +458,11 @@ private void OpenDialogHandler(object sender, ExecutedRoutedEventArgs executedRo
             executedRoutedEventArgs.Handled = true;
         }
 
+        private void CloseDialogCanExecute(object sender, CanExecuteRoutedEventArgs canExecuteRoutedEventArgs)
+        {
+            canExecuteRoutedEventArgs.CanExecute = _session != null;
+        }
+
         private void CloseDialogHandler(object sender, ExecutedRoutedEventArgs executedRoutedEventArgs)
         {
             if (executedRoutedEventArgs.Handled) return;