From 49baee26a9c9f1b88b002da1bb7eefaa95816538 Mon Sep 17 00:00:00 2001
From: msynk <msynk@outlook.com>
Date: Thu, 16 Jul 2026 21:18:45 +0330
Subject: [PATCH 1/2] improve BitMessageBox component #12672

---
 .../MessageBox/BitMessageBoxService.cs        | 29 +++++++++----
 .../Extras/MessageBox/BitMessageBoxDemo.razor | 41 +++++++++++++++----
 .../MessageBox/BitMessageBoxDemo.razor.cs     | 14 +++++++
 .../BitMessageBoxDemo.razor.samples.cs        | 38 ++++++++++++++---
 4 files changed, 102 insertions(+), 20 deletions(-)

diff --git a/src/BlazorUI/Bit.BlazorUI.Extras/Components/MessageBox/BitMessageBoxService.cs b/src/BlazorUI/Bit.BlazorUI.Extras/Components/MessageBox/BitMessageBoxService.cs
index 7b923dda89..3475e76e1e 100644
--- a/src/BlazorUI/Bit.BlazorUI.Extras/Components/MessageBox/BitMessageBoxService.cs
+++ b/src/BlazorUI/Bit.BlazorUI.Extras/Components/MessageBox/BitMessageBoxService.cs
@@ -1,23 +1,38 @@
-namespace Bit.BlazorUI;
+namespace Bit.BlazorUI;
 
 /// <summary>
-/// A wrapper serive around the <see cref="BitModalService"/> to enhance showing message boxes.
+/// A wrapper service around the <see cref="BitProModalService"/> and <see cref="BitModalService"/> to enhance showing message boxes.
+/// It works with either of these services when available and prefers the <see cref="BitProModalService"/> when both are available.
 /// </summary>
-public class BitMessageBoxService(BitModalService modalService)
+public class BitMessageBoxService(BitProModalService? proModalService = null, BitModalService? modalService = null)
 {
     /// <summary>
-    /// Shows a <see cref="BitMessageBox"/> inside a <see cref="BitModal"/> using the <see cref="BitModalService"/>.
+    /// Shows a <see cref="BitMessageBox"/> inside a <see cref="BitProModal"/> using the <see cref="BitProModalService"/> when available,
+    /// otherwise inside a <see cref="BitModal"/> using the <see cref="BitModalService"/>.
     /// </summary>
     public async Task Show(string title, string body)
     {
-        BitModalReference modalRef = default!;
+        Func<Task> closeModal = () => Task.CompletedTask;
         Dictionary<string, object> parameters = new()
         {
             { nameof(BitMessageBox.Title), title },
             { nameof(BitMessageBox.Body), body },
-            { nameof(BitMessageBox.OnClose), EventCallback.Factory.Create(this, () => modalRef.Close()) }
+            { nameof(BitMessageBox.OnClose), EventCallback.Factory.Create(this, () => closeModal()) }
         };
 
-        modalRef = await modalService.Show<BitMessageBox>(parameters);
+        if (proModalService is not null)
+        {
+            var modalRef = await proModalService.Show<BitMessageBox>(parameters);
+            closeModal = modalRef.Close;
+        }
+        else if (modalService is not null)
+        {
+            var modalRef = await modalService.Show<BitMessageBox>(parameters);
+            closeModal = modalRef.Close;
+        }
+        else
+        {
+            throw new InvalidOperationException("Neither BitProModalService nor BitModalService is available. Register at least one of them to use BitMessageBoxService.");
+        }
     }
 }
diff --git a/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor b/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor
index a39946b5bd..ad6280cc5d 100644
--- a/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor
+++ b/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor
@@ -1,4 +1,4 @@
-@page "/components/messagebox"
+@page "/components/messagebox"
 
 <PageOutlet Url="components/messagebox"
             Title="MessageBox"
@@ -25,28 +25,55 @@
     </NotesTemplate>
     <Examples>
         <DemoExample Title="Basic" RazorCode="@example1RazorCode" Id="example1">
+            <div>The basic usage of the BitMessageBox, rendered inline inside a BitCard.</div>
+            <br />
             <BitCard Style="padding:0">
                 <BitMessageBox Title="It's a title" Body="It's a body." />
             </BitCard>
         </DemoExample>
 
         <DemoExample Title="BitModal" RazorCode="@example2RazorCode" CsharpCode="@example2CsharpCode" Id="example2">
+            <div>Show the BitMessageBox inside a BitModal component and close it using the OnClose event.</div>
+            <br />
             <BitButton OnClick="() => isModalOpen = true">Show</BitButton>
             <BitModal @bind-IsOpen="isModalOpen">
                 <BitMessageBox OnClose="() => isModalOpen = false" Title="This is the Title" Body="This is the Body!" />
             </BitModal>
         </DemoExample>
 
-        <DemoExample Title="BitModalService" RazorCode="@example3RazorCode" CsharpCode="@example3CsharpCode" Id="example3">
+        <DemoExample Title="BitProModal" RazorCode="@example3RazorCode" CsharpCode="@example3CsharpCode" Id="example3">
+            <div>Show the BitMessageBox inside a BitProModal component and close it using the OnClose event.</div>
+            <br />
+            <BitButton OnClick="() => isProModalOpen = true">Show</BitButton>
+            <BitProModal @bind-IsOpen="isProModalOpen">
+                <BitMessageBox OnClose="() => isProModalOpen = false" Title="This is the Title" Body="This is the Body!" />
+            </BitProModal>
+        </DemoExample>
+
+        <DemoExample Title="BitModalService" RazorCode="@example4RazorCode" CsharpCode="@example4CsharpCode" Id="example4">
+            <div>Show the BitMessageBox as the content of a modal shown by the BitModalService.</div>
+            <br />
             <BitButton OnClick="ShowMessageBox">Show MessageBox</BitButton>
         </DemoExample>
 
-        <DemoExample Title="BitMessageBoxService" RazorCode="@example4RazorCode" CsharpCode="@example4CsharpCode" Id="example4">
+        <DemoExample Title="BitProModalService" RazorCode="@example5RazorCode" CsharpCode="@example5CsharpCode" Id="example5">
+            <div>Show the BitMessageBox as the content of a pro modal shown by the BitProModalService.</div>
+            <br />
+            <BitButton OnClick="ShowProMessageBox">Show MessageBox</BitButton>
+        </DemoExample>
+
+        <DemoExample Title="BitMessageBoxService" RazorCode="@example6RazorCode" CsharpCode="@example6CsharpCode" Id="example6">
+            <div>
+                Show the BitMessageBox with a simple call to the Show method of the BitMessageBoxService.
+                This service uses the BitProModalService or the BitModalService (whichever is available) to show the message box,
+                preferring the BitProModalService when both are available.
+            </div>
+            <br />
             <BitButton OnClick="ShowMessageBoxService">Show MessageBox</BitButton>
         </DemoExample>
 
-        <DemoExample Title="Style & Class" RazorCode="@example5RazorCode" Id="example5">
-            <div>Customize the appearance of BitActionButton using styles and CSS classes.</div>
+        <DemoExample Title="Style & Class" RazorCode="@example7RazorCode" Id="example7">
+            <div>Customize the appearance of BitMessageBox using styles and CSS classes.</div>
             <br />
             <div>
                 <BitCard Style="padding:0">
@@ -63,7 +90,7 @@
             </div>
         </DemoExample>
 
-        <DemoExample Title="RTL" RazorCode="@example6RazorCode" Id="example6">
+        <DemoExample Title="RTL" RazorCode="@example8RazorCode" Id="example8">
             <div>Use BitMessageBox in right-to-left (RTL).</div>
             <br /><br />
             <div dir="rtl">
@@ -73,4 +100,4 @@
             </div>
         </DemoExample>
     </Examples>
-</DemoPage>
\ No newline at end of file
+</DemoPage>
diff --git a/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor.cs b/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor.cs
index fe7b10e9c4..0fd824db72 100644
--- a/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor.cs
+++ b/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor.cs
@@ -133,6 +133,7 @@ public partial class BitMessageBoxDemo
 
 
     private bool isModalOpen;
+    private bool isProModalOpen;
 
     [AutoInject] private BitModalService modalService { get; set; } = default!;
     private async Task ShowMessageBox()
@@ -147,6 +148,19 @@ private async Task ShowMessageBox()
         modalRef = await modalService.Show<BitMessageBox>(parameters);
     }
 
+    [AutoInject] private BitProModalService proModalService { get; set; } = default!;
+    private async Task ShowProMessageBox()
+    {
+        BitProModalReference modalRef = default!;
+        Dictionary<string, object> parameters = new()
+        {
+            { nameof(BitMessageBox.Title), "This is a title" },
+            { nameof(BitMessageBox.Body), "This is a body." },
+            { nameof(BitMessageBox.OnClose), EventCallback.Factory.Create(this, () => modalRef.Close()) }
+        };
+        modalRef = await proModalService.Show<BitMessageBox>(parameters);
+    }
+
     [AutoInject] private BitMessageBoxService messageBoxService { get; set; } = default!;
     private async Task ShowMessageBoxService()
     {
diff --git a/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor.samples.cs b/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor.samples.cs
index 8fe6ec33e1..42532ff1d2 100644
--- a/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor.samples.cs
+++ b/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor.samples.cs
@@ -1,4 +1,4 @@
-namespace Bit.BlazorUI.Demo.Client.Core.Pages.Components.Extras.MessageBox;
+namespace Bit.BlazorUI.Demo.Client.Core.Pages.Components.Extras.MessageBox;
 
 public partial class BitMessageBoxDemo
 {
@@ -16,10 +16,18 @@ public partial class BitMessageBoxDemo
 private bool isModalOpen;";
 
     private readonly string example3RazorCode = @"
+<BitButton OnClick=""() => isProModalOpen = true"">Show</BitButton>
+<BitProModal @bind-IsOpen=""isProModalOpen"">
+    <BitMessageBox OnClose=""() => isProModalOpen = false"" Title=""This is the Title"" Body=""This is the Body!"" />
+</BitProModal>";
+    private readonly string example3CsharpCode = @"
+private bool isProModalOpen;";
+
+    private readonly string example4RazorCode = @"
 <BitButton OnClick=""ShowMessageBox"">Show MessageBox</BitButton>
 
 <BitModalContainer />";
-    private readonly string example3CsharpCode = @"
+    private readonly string example4CsharpCode = @"
 [AutoInject] private BitModalService modalService { get; set; } = default!;
 private async Task ShowMessageBox()
 {
@@ -33,16 +41,34 @@ private async Task ShowMessageBox()
     modalRef = await modalService.Show<BitMessageBox>(parameters);
 }";
 
-    private readonly string example4RazorCode = @"
+    private readonly string example5RazorCode = @"
+<BitButton OnClick=""ShowProMessageBox"">Show MessageBox</BitButton>
+
+<BitProModalContainer />";
+    private readonly string example5CsharpCode = @"
+[AutoInject] private BitProModalService proModalService { get; set; } = default!;
+private async Task ShowProMessageBox()
+{
+    BitProModalReference modalRef = default!;
+    Dictionary<string, object> parameters = new()
+    {
+        { nameof(BitMessageBox.Title), ""This is a title"" },
+        { nameof(BitMessageBox.Body), ""This is a body."" },
+        { nameof(BitMessageBox.OnClose), EventCallback.Factory.Create(this, () => modalRef.Close()) }
+    };
+    modalRef = await proModalService.Show<BitMessageBox>(parameters);
+}";
+
+    private readonly string example6RazorCode = @"
 <BitButton OnClick=""ShowMessageBoxService"">Show MessageBox</BitButton>";
-    private readonly string example4CsharpCode = @"
+    private readonly string example6CsharpCode = @"
 [AutoInject] private BitMessageBoxService messageBoxService { get; set; } = default!;
 private async Task ShowMessageBoxService()
 {
     await messageBoxService.Show(""TITLE"", ""BODY"");
 }";
 
-    private readonly string example5RazorCode = @"
+    private readonly string example7RazorCode = @"
 <style>
     .custom-msg {
         background: linear-gradient(180deg, #3e0f0f, transparent) #000;
@@ -77,7 +103,7 @@ private async Task ShowMessageBoxService()
                     Classes=""@(new() { Root = ""custom-msg"", OkButton = new() { Root = ""custom-msg-btn"" } })"" />
 </BitCard>";
 
-    private readonly string example6RazorCode = @"
+    private readonly string example8RazorCode = @"
 <BitCard Style=""padding:0"">
     <BitMessageBox Dir=""BitDir.Rtl"" Title=""عنوان پیام"" Body=""متن تست پیام..."" OkText=""تایید"" />
 </BitCard>";

From 0d58fbb01d96382d159241f6c4387c9ba926fe4c Mon Sep 17 00:00:00 2001
From: msynk <msynk@outlook.com>
Date: Fri, 17 Jul 2026 16:20:45 +0330
Subject: [PATCH 2/2] resolve local review findings

---
 .../MessageBox/BitMessageBoxService.cs        | 76 +++++++++++++++----
 .../Components/ProModal/BitProModalService.cs |  8 +-
 .../Surfaces/Modal/BitModalService.cs         |  8 +-
 .../Surfaces/Modal/BitModalServiceBase.cs     | 49 ++++++++++--
 .../Extras/MessageBox/BitMessageBoxDemo.razor |  2 +-
 .../MessageBox/BitMessageBoxDemo.razor.cs     | 16 ++--
 .../BitMessageBoxDemo.razor.samples.cs        | 24 +++---
 7 files changed, 138 insertions(+), 45 deletions(-)

diff --git a/src/BlazorUI/Bit.BlazorUI.Extras/Components/MessageBox/BitMessageBoxService.cs b/src/BlazorUI/Bit.BlazorUI.Extras/Components/MessageBox/BitMessageBoxService.cs
index 3475e76e1e..558630fbf1 100644
--- a/src/BlazorUI/Bit.BlazorUI.Extras/Components/MessageBox/BitMessageBoxService.cs
+++ b/src/BlazorUI/Bit.BlazorUI.Extras/Components/MessageBox/BitMessageBoxService.cs
@@ -1,38 +1,84 @@
-namespace Bit.BlazorUI;
+namespace Bit.BlazorUI;
 
 /// <summary>
 /// A wrapper service around the <see cref="BitProModalService"/> and <see cref="BitModalService"/> to enhance showing message boxes.
 /// It works with either of these services when available and prefers the <see cref="BitProModalService"/> when both are available.
 /// </summary>
+/// <remarks>
+/// A message box only appears if the modal container of the chosen service is mounted in the layout:
+/// <see cref="BitProModalContainer"/> for the <see cref="BitProModalService"/> and <see cref="BitModalContainer"/>
+/// for the <see cref="BitModalService"/>. Because the two services are usually both registered but a layout may
+/// mount only one container, the selection (see <see cref="Show"/>) is driven by which container is actually
+/// mounted rather than by which service is registered, so the message box is not silently swallowed.
+/// </remarks>
 public class BitMessageBoxService(BitProModalService? proModalService = null, BitModalService? modalService = null)
 {
     /// <summary>
-    /// Shows a <see cref="BitMessageBox"/> inside a <see cref="BitProModal"/> using the <see cref="BitProModalService"/> when available,
+    /// Shows a <see cref="BitMessageBox"/> inside a <see cref="BitProModal"/> using the <see cref="BitProModalService"/>,
     /// otherwise inside a <see cref="BitModal"/> using the <see cref="BitModalService"/>.
     /// </summary>
+    /// <remarks>
+    /// Both services are commonly registered together (registering the Extras services adds both), yet whether a
+    /// message box actually renders depends on which modal container is mounted, not on which service is registered:
+    /// a modal shown through a service whose container is absent is silently not rendered. To avoid that, the service
+    /// to use is chosen from container availability (<see cref="BitModalServiceBase{TReference, TParameters}.IsContainerAvailable"/>),
+    /// in this order:
+    /// <list type="number">
+    /// <item>the <see cref="BitProModalService"/> when its <see cref="BitProModalContainer"/> is mounted (preferred when both are);</item>
+    /// <item>otherwise the <see cref="BitModalService"/> when its <see cref="BitModalContainer"/> is mounted;</item>
+    /// <item>otherwise the only registered service — or, when both are registered but neither container is mounted, the
+    /// preferred <see cref="BitProModalService"/> (a misconfiguration that renders nothing regardless: mount a container).</item>
+    /// </list>
+    /// Container availability reflects live state and is reliable at the moment of a user-triggered show, since the
+    /// layout (and thus the container) has already rendered by then.
+    /// </remarks>
+    /// <exception cref="InvalidOperationException">Neither <see cref="BitProModalService"/> nor <see cref="BitModalService"/> is registered.</exception>
     public async Task Show(string title, string body)
     {
-        Func<Task> closeModal = () => Task.CompletedTask;
-        Dictionary<string, object> parameters = new()
+        if (proModalService is null && modalService is null)
         {
-            { nameof(BitMessageBox.Title), title },
-            { nameof(BitMessageBox.Body), body },
-            { nameof(BitMessageBox.OnClose), EventCallback.Factory.Create(this, () => closeModal()) }
-        };
+            throw new InvalidOperationException("Neither BitProModalService nor BitModalService is available. Register at least one of them to use BitMessageBoxService.");
+        }
 
-        if (proModalService is not null)
+        // Choose the service whose container is actually mounted (preferring the pro one), because a modal shown
+        // through a service without a mounted container is silently not rendered. Only when neither container is
+        // mounted do we fall back to the preferred registered service.
+        bool useProModal;
+        if (proModalService is null)
+        {
+            useProModal = false;
+        }
+        else if (modalService is null)
         {
-            var modalRef = await proModalService.Show<BitMessageBox>(parameters);
-            closeModal = modalRef.Close;
+            useProModal = true;
         }
-        else if (modalService is not null)
+        else if (modalService.IsContainerAvailable && !proModalService.IsContainerAvailable)
         {
-            var modalRef = await modalService.Show<BitMessageBox>(parameters);
-            closeModal = modalRef.Close;
+            // Only the classic container is mounted: route to it so the message box actually renders.
+            useProModal = false;
         }
         else
         {
-            throw new InvalidOperationException("Neither BitProModalService nor BitModalService is available. Register at least one of them to use BitMessageBoxService.");
+            // The pro container is mounted, or neither is (nothing renders either way): keep the preferred pro service.
+            useProModal = true;
+        }
+
+        // The parameters are built from the modal reference the service hands back, so the OnClose callback
+        // closes this very modal without a window where the reference isn't assigned yet.
+        if (useProModal)
+        {
+            await proModalService!.Show<BitMessageBox>(modalRef => BuildParameters(title, body, modalRef.Close));
+        }
+        else
+        {
+            await modalService!.Show<BitMessageBox>(modalRef => BuildParameters(title, body, modalRef.Close));
         }
     }
+
+    private Dictionary<string, object> BuildParameters(string title, string body, Func<Task> onClose) => new()
+    {
+        { nameof(BitMessageBox.Title), title },
+        { nameof(BitMessageBox.Body), body },
+        { nameof(BitMessageBox.OnClose), EventCallback.Factory.Create(this, onClose) }
+    };
 }
diff --git a/src/BlazorUI/Bit.BlazorUI.Extras/Components/ProModal/BitProModalService.cs b/src/BlazorUI/Bit.BlazorUI.Extras/Components/ProModal/BitProModalService.cs
index c4306ca6f6..3e5396c9b9 100644
--- a/src/BlazorUI/Bit.BlazorUI.Extras/Components/ProModal/BitProModalService.cs
+++ b/src/BlazorUI/Bit.BlazorUI.Extras/Components/ProModal/BitProModalService.cs
@@ -1,8 +1,14 @@
-namespace Bit.BlazorUI;
+namespace Bit.BlazorUI;
 
 /// <summary>
 /// A service to show any content inside a centralized <see cref="BitProModal"/> using <see cref="BitProModalContainer"/>.
 /// </summary>
+/// <remarks>
+/// A <see cref="BitProModalContainer"/> must be mounted in the layout for shown modals to render: a non-persistent modal
+/// shown while no container is mounted is silently not rendered (see the base type remarks). Use
+/// <see cref="BitModalServiceBase{TReference, TParameters}.IsContainerAvailable"/> to check whether a container is
+/// currently mounted before showing a modal.
+/// </remarks>
 public class BitProModalService : BitModalServiceBase<BitProModalReference, BitProModalParameters>
 {
     protected override BitProModalReference CreateReference(bool persistent)
diff --git a/src/BlazorUI/Bit.BlazorUI/Components/Surfaces/Modal/BitModalService.cs b/src/BlazorUI/Bit.BlazorUI/Components/Surfaces/Modal/BitModalService.cs
index 4ec34c67e7..acab52b703 100644
--- a/src/BlazorUI/Bit.BlazorUI/Components/Surfaces/Modal/BitModalService.cs
+++ b/src/BlazorUI/Bit.BlazorUI/Components/Surfaces/Modal/BitModalService.cs
@@ -1,8 +1,14 @@
-namespace Bit.BlazorUI;
+namespace Bit.BlazorUI;
 
 /// <summary>
 /// A core service to show any content inside a centralized <see cref="BitModal"/> using <see cref="BitModalContainer"/>.
 /// </summary>
+/// <remarks>
+/// A <see cref="BitModalContainer"/> must be mounted in the layout for shown modals to render: a non-persistent modal
+/// shown while no container is mounted is silently not rendered (see the base type remarks). Use
+/// <see cref="BitModalServiceBase{TReference, TParameters}.IsContainerAvailable"/> to check whether a container is
+/// currently mounted before showing a modal.
+/// </remarks>
 public class BitModalService : BitModalServiceBase<BitModalReference, BitModalParameters>
 {
     protected override BitModalReference CreateReference(bool persistent)
diff --git a/src/BlazorUI/Bit.BlazorUI/Components/Surfaces/Modal/BitModalServiceBase.cs b/src/BlazorUI/Bit.BlazorUI/Components/Surfaces/Modal/BitModalServiceBase.cs
index 4ee8b29001..4cdee1071c 100644
--- a/src/BlazorUI/Bit.BlazorUI/Components/Surfaces/Modal/BitModalServiceBase.cs
+++ b/src/BlazorUI/Bit.BlazorUI/Components/Surfaces/Modal/BitModalServiceBase.cs
@@ -1,4 +1,4 @@
-using System.Diagnostics.CodeAnalysis;
+using System.Diagnostics.CodeAnalysis;
 
 namespace Bit.BlazorUI;
 
@@ -79,6 +79,24 @@ public void RemoveContainer(BitModalContainerBase<TReference, TParameters> conta
         }
     }
 
+    /// <summary>
+    /// Whether a modal container is currently mounted for this service, i.e. whether a <c>Show</c> call right now
+    /// would actually render its modal.
+    /// </summary>
+    /// <remarks>
+    /// This reflects LIVE state, not registration: the service being registered in DI does not imply a container
+    /// exists. A container attaches during its own initialization (after its first render) via <see cref="InitContainer"/>
+    /// and detaches on dispose via <see cref="RemoveContainer"/>, so this can be <c>false</c> very early in a render
+    /// cycle before any container has initialized, and it can flip back to <c>false</c> across a container remount.
+    /// It is therefore reliable at the moment of a user-triggered <c>Show</c> (the layout has long since rendered),
+    /// but should not be treated as a permanent guarantee.
+    /// <br/>
+    /// The main use is a caller that can show through more than one modal service (for example a wrapper that prefers
+    /// one service but can fall back to another) and wants to pick a service whose container is actually mounted,
+    /// because a non-persistent modal shown while this is <c>false</c> is silently not rendered (see the type remarks).
+    /// </remarks>
+    public bool IsContainerAvailable => _container is not null;
+
     /// <summary>
     /// Closes an already opened modal using its reference.
     /// </summary>
@@ -147,7 +165,7 @@ public Task Refresh(TReference modalRef)
     public Task<TReference> Show<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.All)] T>(
         bool persistent = false) where T : IComponent
     {
-        return Show<T>(null, null, persistent);
+        return Show<T>((Dictionary<string, object>?)null, null, persistent);
     }
 
     /// <summary>
@@ -174,7 +192,7 @@ public Task Refresh(TReference modalRef)
     public Task<TReference> Show<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.All)] T>(
         TParameters modalParameters) where T : IComponent
     {
-        return Show<T>(null, modalParameters, false);
+        return Show<T>((Dictionary<string, object>?)null, modalParameters, false);
     }
 
     /// <summary>
@@ -183,22 +201,43 @@ public Task Refresh(TReference modalRef)
     public Task<TReference> Show<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.All)] T>(
         TParameters? modalParameters, bool persistent = false) where T : IComponent
     {
-        return Show<T>(null, modalParameters, persistent);
+        return Show<T>((Dictionary<string, object>?)null, modalParameters, persistent);
     }
 
     /// <summary>
     /// Shows a new modal with a custom component as its content with custom parameters for the custom component and the modal.
     /// </summary>
-    public async Task<TReference> Show<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.All)] T>(
+    public Task<TReference> Show<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.All)] T>(
         Dictionary<string, object>? parameters,
         TParameters? modalParameters,
         bool persistent = false) where T : IComponent
     {
+        return Show<T>(_ => parameters, modalParameters, persistent);
+    }
+
+    /// <summary>
+    /// Shows a new modal, building the content component's parameters from a factory that receives the modal reference.
+    /// Use this overload when a parameter needs the reference itself (e.g. an <c>OnClose</c> callback that closes this
+    /// very modal): the reference is handed to the factory before the content is rendered, so the callback can never
+    /// observe an unassigned reference the way it can when the reference is only captured after Show returns.
+    /// </summary>
+    public async Task<TReference> Show<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.All)] T>(
+        Func<TReference, Dictionary<string, object>?> parametersFactory,
+        TParameters? modalParameters = null,
+        bool persistent = false) where T : IComponent
+    {
+        ArgumentNullException.ThrowIfNull(parametersFactory);
+
         var componentType = typeof(T);
 
         var modalReference = CreateReference(persistent);
         modalReference.SetParameters(modalParameters);
 
+        // Build the content parameters with the reference already in hand so a parameter such as an OnClose
+        // callback can capture modalReference.Close directly, closing the window a caller would otherwise face
+        // when wiring the close callback only after Show returns.
+        var parameters = parametersFactory(modalReference);
+
         var content = new RenderFragment(builder =>
         {
             var i = 0;
diff --git a/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor b/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor
index ad6280cc5d..d95cd93cab 100644
--- a/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor
+++ b/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor
@@ -1,4 +1,4 @@
-@page "/components/messagebox"
+@page "/components/messagebox"
 
 <PageOutlet Url="components/messagebox"
             Title="MessageBox"
diff --git a/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor.cs b/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor.cs
index 0fd824db72..49fe4e347c 100644
--- a/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor.cs
+++ b/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor.cs
@@ -138,27 +138,23 @@ public partial class BitMessageBoxDemo
     [AutoInject] private BitModalService modalService { get; set; } = default!;
     private async Task ShowMessageBox()
     {
-        BitModalReference modalRef = default!;
-        Dictionary<string, object> parameters = new()
+        await modalService.Show<BitMessageBox>(modalRef => new()
         {
             { nameof(BitMessageBox.Title), "This is a title" },
             { nameof(BitMessageBox.Body), "This is a body." },
-            { nameof(BitMessageBox.OnClose), EventCallback.Factory.Create(this, () => modalRef.Close()) }
-        };
-        modalRef = await modalService.Show<BitMessageBox>(parameters);
+            { nameof(BitMessageBox.OnClose), EventCallback.Factory.Create(this, modalRef.Close) }
+        });
     }
 
     [AutoInject] private BitProModalService proModalService { get; set; } = default!;
     private async Task ShowProMessageBox()
     {
-        BitProModalReference modalRef = default!;
-        Dictionary<string, object> parameters = new()
+        await proModalService.Show<BitMessageBox>(modalRef => new()
         {
             { nameof(BitMessageBox.Title), "This is a title" },
             { nameof(BitMessageBox.Body), "This is a body." },
-            { nameof(BitMessageBox.OnClose), EventCallback.Factory.Create(this, () => modalRef.Close()) }
-        };
-        modalRef = await proModalService.Show<BitMessageBox>(parameters);
+            { nameof(BitMessageBox.OnClose), EventCallback.Factory.Create(this, modalRef.Close) }
+        });
     }
 
     [AutoInject] private BitMessageBoxService messageBoxService { get; set; } = default!;
diff --git a/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor.samples.cs b/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor.samples.cs
index 42532ff1d2..909a1164ff 100644
--- a/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor.samples.cs
+++ b/src/BlazorUI/Demo/Client/Bit.BlazorUI.Demo.Client.Core/Pages/Components/Extras/MessageBox/BitMessageBoxDemo.razor.samples.cs
@@ -1,4 +1,4 @@
-namespace Bit.BlazorUI.Demo.Client.Core.Pages.Components.Extras.MessageBox;
+namespace Bit.BlazorUI.Demo.Client.Core.Pages.Components.Extras.MessageBox;
 
 public partial class BitMessageBoxDemo
 {
@@ -31,14 +31,12 @@ public partial class BitMessageBoxDemo
 [AutoInject] private BitModalService modalService { get; set; } = default!;
 private async Task ShowMessageBox()
 {
-    BitModalReference modalRef = default!;
-    Dictionary<string, object> parameters = new()
+    await modalService.Show<BitMessageBox>(modalRef => new()
     {
         { nameof(BitMessageBox.Title), ""This is a title"" },
         { nameof(BitMessageBox.Body), ""This is a body."" },
-        { nameof(BitMessageBox.OnClose), EventCallback.Factory.Create(this, () => modalRef.Close()) }
-    };
-    modalRef = await modalService.Show<BitMessageBox>(parameters);
+        { nameof(BitMessageBox.OnClose), EventCallback.Factory.Create(this, modalRef.Close) }
+    });
 }";
 
     private readonly string example5RazorCode = @"
@@ -49,18 +47,20 @@ private async Task ShowMessageBox()
 [AutoInject] private BitProModalService proModalService { get; set; } = default!;
 private async Task ShowProMessageBox()
 {
-    BitProModalReference modalRef = default!;
-    Dictionary<string, object> parameters = new()
+    await proModalService.Show<BitMessageBox>(modalRef => new()
     {
         { nameof(BitMessageBox.Title), ""This is a title"" },
         { nameof(BitMessageBox.Body), ""This is a body."" },
-        { nameof(BitMessageBox.OnClose), EventCallback.Factory.Create(this, () => modalRef.Close()) }
-    };
-    modalRef = await proModalService.Show<BitMessageBox>(parameters);
+        { nameof(BitMessageBox.OnClose), EventCallback.Factory.Create(this, modalRef.Close) }
+    });
 }";
 
     private readonly string example6RazorCode = @"
-<BitButton OnClick=""ShowMessageBoxService"">Show MessageBox</BitButton>";
+<BitButton OnClick=""ShowMessageBoxService"">Show MessageBox</BitButton>
+
+@* The service uses the BitProModalService when available, otherwise the BitModalService. *@
+@* Mount the matching container: BitProModalContainer for the pro modal, BitModalContainer otherwise. *@
+<BitProModalContainer />";
     private readonly string example6CsharpCode = @"
 [AutoInject] private BitMessageBoxService messageBoxService { get; set; } = default!;
 private async Task ShowMessageBoxService()