Update Visual Basic event handler article to use generic examples instead of WinForms (#48221)

* Initial plan

* Replace WinForms-specific examples with generic event handling examples

Co-authored-by: BillWagner <[email protected]>

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: BillWagner <[email protected]>

Author: Copilot

docs/visual-basic/programming-guide/language-features/procedures/how-to-call-an-event-handler.md

@@ -43,7 +43,7 @@ You can associate more than one event handler with the same event. In some cases
 
 3. When the event occurs, Visual Basic automatically calls the `Sub` procedure. Your code can use a `RaiseEvent` statement to make the event occur.
 
-    The following example uses the [AddHandler statement](../../../language-reference/statements/addhandler-statement.md) in the constructor to associate the `OnFormClosing` procedure as an event handler for <xref:System.Windows.Forms.Form.FormClosing>.
+    The following example uses the [AddHandler statement](../../../language-reference/statements/addhandler-statement.md) in the constructor to associate the `OnTimerElapsed` procedure as an event handler for a custom timer event.
 
     :::code language="vb" source="snippets/how-to-call-an-event-handler/SpecialForm.vb" id="5":::
 

docs/visual-basic/programming-guide/language-features/procedures/snippets/how-to-call-an-event-handler/CallEventHandler.vbproj

@@ -1,17 +1,9 @@
-<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <OutputType>WinExe</OutputType>
-    <TargetFramework>net8.0-windows</TargetFramework>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
     <RootNamespace>CallEventHandler</RootNamespace>
-    <StartupObject>CallEventHandler.SpecialForm</StartupObject>
-    <UseWindowsForms>true</UseWindowsForms>
   </PropertyGroup>
 
-  <ItemGroup>
-    <Import Include="System.Data" />
-    <Import Include="System.Drawing" />
-    <Import Include="System.Windows.Forms" />
-  </ItemGroup>
-
 </Project>

docs/visual-basic/programming-guide/language-features/procedures/snippets/how-to-call-an-event-handler/SpecialForm.Designer.vb

@@ -1,22 +1,74 @@
-Public Class SpecialForm
-    '<Snippet5>
-    Sub New()
-        InitializeComponent()
-        AddHandler Me.FormClosing, AddressOf OnFormClosing
-    End Sub
-
-    Private Sub OnFormClosing(sender As Object, e As FormClosingEventArgs)
-        ' Insert code to deal with impending closure of this form.
+'<Snippet4>
+' Example showing event handling with Handles and WithEvents
+Public Class EventPublisher
+    Public Event SomethingHappened()
+    
+    Public Sub CauseEvent()
+        ' Raise the event when something interesting happens
+        RaiseEvent SomethingHappened()
     End Sub
-    '</Snippet5>
 End Class
 
-'<Snippet4>
-Public Class RaisesEvent
-    Public Event SomethingHappened()
-    Dim WithEvents happenObj As New RaisesEvent
-    Public Sub ProcessHappen() Handles happenObj.SomethingHappened
+Public Class EventSubscriber
+    ' Declare a WithEvents variable
+    Dim WithEvents eventObj As New EventPublisher
+    
+    ' Handle the event using Handles clause
+    Public Sub ProcessHappen() Handles eventObj.SomethingHappened
         ' Insert code to handle somethingHappened event.
+        Console.WriteLine("Event handled using Handles clause!")
+    End Sub
+    
+    Public Sub TriggerEvent()
+        eventObj.CauseEvent()
     End Sub
 End Class
 '</Snippet4>
+
+'<Snippet5>
+' Example showing event handling with AddHandler
+Public Class Timer
+    Public Event TimerElapsed(ByVal message As String)
+    
+    Public Sub Start()
+        ' Simulate timer elapsed
+        RaiseEvent TimerElapsed("Timer has elapsed!")
+    End Sub
+End Class
+
+Public Class Application
+    Private appTimer As New Timer()
+    
+    Sub New()
+        ' Use AddHandler to dynamically associate event handler
+        AddHandler appTimer.TimerElapsed, AddressOf OnTimerElapsed
+    End Sub
+
+    Private Sub OnTimerElapsed(ByVal message As String)
+        ' Insert code to handle timer elapsed event
+        Console.WriteLine($"Handling timer event: {message}")
+    End Sub
+    
+    Public Sub StartTimer()
+        appTimer.Start()
+    End Sub
+End Class
+'</Snippet5>
+
+' Demo program to show both event handling approaches
+Module Program
+    Sub Main()
+        ' Demonstrate Handles approach
+        Console.WriteLine("=== Demonstrating Handles approach ===")
+        Dim subscriber As New EventSubscriber()
+        subscriber.TriggerEvent()
+        
+        ' Demonstrate AddHandler approach
+        Console.WriteLine("=== Demonstrating AddHandler approach ===")
+        Dim app As New Application()
+        app.StartTimer()
+        
+        Console.WriteLine("Press any key to exit...")
+        Console.ReadKey()
+    End Sub
+End Module