feat: IDialogService.Close returns boolean indicating success (#116)

IDialogService.Close returns false instead of throwing an exception when failing to close a dialog. This behavior aligns with the behavior of IDialogService.Activate.

CHANGELOG.md

@@ -8,6 +8,10 @@ This project adheres to [Semantic Versioning](http://semver.org/) and is followi
 
 NOTE: Features with breaking changes are found on branch [releases/v8](https://github.com/FantasticFiasco/mvvm-dialogs/tree/releases/v8) and will stay there until a new major version is released. Until then the features have been published to [www.nuget.org](https://www.nuget.org/packages/MvvmDialogs/) as pre-releases to v8.
 
+### :syringe: Changed
+
+- [#116](https://github.com/FantasticFiasco/mvvm-dialogs/issues/116) [BREAKING CHANGE] `IDialogService.Close` returns `false` instead of throwing an exception when failing to close a dialog. This behavior aligns with the behavior of `IDialogService.Activate`.
+
 ### :syringe: Fixed
 
 - Specify dependency groups in nuspec for each supported framework version

src/net/DialogService.cs

@@ -162,25 +162,30 @@ public bool Activate(INotifyPropertyChanged viewModel)
         }
 
         /// <inheritdoc />
-        public void Close(INotifyPropertyChanged viewModel)
+        public bool Close(INotifyPropertyChanged viewModel)
         {
             if (viewModel == null) throw new ArgumentNullException(nameof(viewModel));
 
             foreach (Window? window in Application.Current.Windows)
             {
-                if (window == null)
+                if (window == null || !viewModel.Equals(window.DataContext))
                 {
                     continue;
                 }
 
-                if (viewModel.Equals(window.DataContext))
+                try
                 {
                     window.Close();
-                    return;
+                    return true;
+                }
+                catch (Exception e)
+                {
+                    Logger.Write($"Failed to close dialog: {e}");
+                    break;
                 }
             }
 
-            throw new DialogNotFoundException();
+            return false;
         }
 
         /// <inheritdoc />

src/net/IDialogService.cs

@@ -134,10 +134,10 @@ void Show(
         /// <see cref="Show{T}"/> or <see cref="ShowCustom{T}"/>.
         /// </summary>
         /// <param name="viewModel">The view model of the dialog to close.</param>
-        /// <exception cref="DialogNotFoundException">
-        /// No dialog is found with specified view model as data context.
-        /// </exception>
-        void Close(INotifyPropertyChanged viewModel);
+        /// <returns>
+        /// true if the <see cref="Window"/> was successfully closed; otherwise, false.
+        /// </returns>
+        bool Close(INotifyPropertyChanged viewModel);
 
         /// <summary>
         /// Displays a message box that has a message, title bar caption, button, and icon; and