Add `CancelClosingModalWhenFocusLost` extension method.

framework/src/Volo.Abp.BlazoriseUI/AbpBlazoriseUiModalExtensions.cs

@@ -0,0 +1,15 @@
+using System.Threading.Tasks;
+using Blazorise;
+
+namespace Volo.Abp.BlazoriseUI;
+
+public static class AbpBlazoriseUiModalExtensions
+{
+    public static Task CancelClosingModalWhenFocusLost(this Modal modal, ModalClosingEventArgs eventArgs)
+    {
+        // cancel close if clicked outside of modal area
+        eventArgs.Cancel = eventArgs.CloseReason == CloseReason.FocusLostClosing;
+
+        return Task.CompletedTask;
+    }
+}