diff --git a/HotKeys2/Toolbelt.Blazor.HotKeys2.csproj b/HotKeys2/Toolbelt.Blazor.HotKeys2.csproj
index 647de18..4424a55 100644
--- a/HotKeys2/Toolbelt.Blazor.HotKeys2.csproj
+++ b/HotKeys2/Toolbelt.Blazor.HotKeys2.csproj
@@ -14,7 +14,7 @@
   </PropertyGroup>
 
   <PropertyGroup>
-    <Version>3.1.0-preview.2</Version>
+    <Version>3.1.0</Version>
     <Copyright>Copyright © 2022-2023 J.Sakamoto, Mozilla Public License 2.0</Copyright>
     <Authors>J.Sakamoto</Authors>
     <RepositoryType>git</RepositoryType>
diff --git a/README.md b/README.md
index ed81434..0d77cd9 100644
--- a/README.md
+++ b/README.md
@@ -22,7 +22,7 @@ this.HotKeysContext = this.HotKeys.CreateContext()
 
 ## Supported Blazor versions
 
-This library suppots ASP.NET Core Blazor version 6.0, 7.0, or later.
+This library suppots ASP.NET Core Blazor version 6.0, 7.0, 8.0 or later.
 
 ## How to install and use?
 
@@ -78,17 +78,17 @@ Please remember that you have to keep the `HotKeys Context` object in the compon
 ```csharp
 @code {
 
-  HotKeysContext HotKeysContext;
+  private HotKeysContext? HotKeysContext;
 
   protected override void OnInitialized()
   {
     this.HotKeysContext = this.HotKeys.CreateContext()
-      .Add(ModCode.Ctrl|ModCode.Shift, Code.A, FooBar, "do foo bar.")
+      .Add(ModCode.Ctrl|ModCode.Shift, Code.A, FooBar, new() { Description = "do foo bar." })
       .Add(...)
       ...;
   }
 
-  void FooBar() // 👈 This will be invoked when Ctrl+Shift+A typed.
+  private void FooBar() // 👈 This will be invoked when Ctrl+Shift+A typed.
   {
     ...
   }
@@ -109,7 +109,7 @@ Please remember that you have to keep the `HotKeys Context` object in the compon
   ...
   public void Dispose()
   {
-    this.HotKeysContext.Dispose(); // 👈 1. Add this
+    this.HotKeysContext?.Dispose(); // 👈 1. Add this
   }
 }
 ```
@@ -124,49 +124,60 @@ The complete source code (.razor) of this component is bellow.
 
 @code {
 
-  HotKeysContext HotKeysContext;
+  private HotKeysContext? HotKeysContext;
 
   protected override void OnInitialized()
   {
     this.HotKeysContext = this.HotKeys.CreateContext()
-      .Add(ModCode.Ctrl|ModCode.Shift, Code.A, FooBar, "do foo bar.")
+      .Add(ModCode.Ctrl|ModCode.Shift, Code.A, FooBar, new() { Description = "do foo bar." })
   }
 
-  void FooBar()
+  private void FooBar()
   {
     // Do something here.
   }
 
   public void Dispose()
   {
-    this.HotKeysContext.Dispose();
+    this.HotKeysContext?.Dispose();
   }
 }
 ```
 ### How to enable / disable hotkeys depending on which element has focus
 
-You can specify enabling/disabling hotkeys depending on which kind of element has focus at the hotkeys registration via a combination of the `Exclude` flags in optional arguments of the `HotKeysContext.Add()` method.
+You can specify enabling/disabling hotkeys depending on which kind of element has focus at the hotkeys registration via a combination of the `Exclude` flags in the property of the option object argument of the `HotKeysContext.Add()` method.
 
-By default, the `Exclude` flags argument is the following combination.
+The default value of the option object's `Exclude` flag property is the following combination.
 
 ```csharp
 Exclude.InputText | Exclude.InputNonText | Exclude.TextArea
 ```
 
-This means, by default, hotkeys are disabled when the focus is in `<input>` (with any `type`) or `<textarea>` elements.
+This means hotkeys are disabled when the focus is in `<input>` (with any `type`) or `<textarea>` elements by default.
 
-If you want to enable hotkeys even when an `<input type="text"/>` has focus, you can do it as below.
+If you want to enable hotkeys even when an `<input type="text"/>` has focus, you can implement it as below.
 
 ```csharp
 ... this.HotKeys.CreateContext()
-  .Add(Code.A, OnKeyDownA, "...", 
-    // 👇 Specify the "exclude" argument.
-    exclude: Exclude.InputNonText | Exclude.TextArea)
+  .Add(Code.A, OnKeyDownA, new() { 
+    // 👇 Specify the "Exclude" property of the options.
+    Exclude = Exclude.InputNonText | Exclude.TextArea })
+  ...
+```
+
+You can also specify the elements that are disabled hotkeys by CSS query selector string via the `ExcludeSelector` property of the options object.
+
+```csharp
+... this.HotKeys.CreateContext()
+  .Add(Code.A, OnKeyDownA, new() { 
+    // 👇 Specify the CSS query selector to the "ExcludeSelector" property of the options.
+    ExcludeSelector = ".disabled-hotkeys-area" })
   ...
 ```
 
 And you can specify the `Exclude.ContentEditable` to register the unavailable hotkey when any "contenteditable" applied elements have focus.
 
+
 ## `Code` vs. `Key` - which way should I use to?
 
 There are two ways to register hotkeys in the `HotKeysContext`.
diff --git a/RELEASE-NOTES.txt b/RELEASE-NOTES.txt
index 37a0cc7..90e9511 100644
--- a/RELEASE-NOTES.txt
+++ b/RELEASE-NOTES.txt
@@ -1,3 +1,7 @@
+v.3.1.0
+- Improve: Exclude by a custom CSS query selector.
+- Improve: Add .NET 8 support.
+
 v.3.0.0
 - Improve: explicit calling StateHasChanged is no longer needed inside hotkey handler methods.
 
diff --git a/SampleSites/Components/SampleSite.Components.csproj b/SampleSites/Components/SampleSite.Components.csproj
index 8887864..525fd8e 100644
--- a/SampleSites/Components/SampleSite.Components.csproj
+++ b/SampleSites/Components/SampleSite.Components.csproj
@@ -20,7 +20,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Toolbelt.Blazor.HotKeys2" Version="3.1.0-preview.2" />
+    <PackageReference Include="Toolbelt.Blazor.HotKeys2" Version="3.1.0" />
     <!--<ProjectReference Include="..\..\HotKeys2\Toolbelt.Blazor.HotKeys2.csproj" />-->
   </ItemGroup>