Console.CancelKeyPress Event

Occurs when the Control modifier key (CTRL) and C console key (C) are pressed simultaneously (CTRL+C).

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

'Declaration
Public Shared Event CancelKeyPress As ConsoleCancelEventHandler
'Usage
Dim handler As ConsoleCancelEventHandler 

AddHandler Console.CancelKeyPress, handler

This event is used in conjunction with System.ConsoleCancelEventHandler and System.ConsoleCancelEventArgs. The CancelKeyPress event enables a console application to intercept the CTRL+C signal so the application can decide whether to continue executing or terminate. For more information about handling events, see Consuming Events.

Use this event to explicitly control how your application responds to the CTRL+C signal. If your application has simple requirements, you can use the TreatControlCAsInput property instead of this event.

The event handler for this event is executed on a thread pool thread.

The following code example demonstrates how the CancelKeyPress event is used.

Class Sample
    Public Shared Sub Main() 
        Dim cki As ConsoleKeyInfo

        Console.Clear()

        ' Establish an event handler to process key press events. 
        AddHandler Console.CancelKeyPress, AddressOf myHandler

        While True
            Console.Write("Press any key, or 'X' to quit, or ")
            Console.WriteLine("CTRL+C to interrupt the read operation:")

            ' Start a console read operation. Do not display the input.
            cki = Console.ReadKey(True)

            ' Announce the name of the key that was pressed .
            Console.WriteLine("  Key pressed: {0}" & vbCrLf, cki.Key)

            ' Exit if the user pressed the 'X' key. 
            If cki.Key = ConsoleKey.X Then Exit While 
        End While 
    End Sub 
   '   When you press CTRL+C, the read operation is interrupted and the  
   '   console cancel event handler, myHandler, is invoked. Upon entry  
   '   to the event handler, the Cancel property is false, which means  
   '   the current process will terminate when the event handler terminates.  
   '   However, the event handler sets the Cancel property to true, which  
   '   means the process will not terminate and the read operation will resume. 
    Protected Shared Sub myHandler(ByVal sender As Object, _
                                   ByVal args As ConsoleCancelEventArgs) 
        ' Announce that the event handler has been invoked.
        Console.WriteLine(vbCrLf & "The read operation has been interrupted.")

        ' Announce which key combination was pressed.
        Console.WriteLine("  Key pressed: {0}", args.SpecialKey)

        ' Announce the initial value of the Cancel property.
        Console.WriteLine("  Cancel property: {0}", args.Cancel)

        ' Set the Cancel property to true to prevent the process from terminating.
        Console.WriteLine("Setting the Cancel property to true...")
        args.Cancel = True 

        ' Announce the new value of the Cancel property.
        Console.WriteLine("  Cancel property: {0}", args.Cancel)
        Console.WriteLine("The read operation will resume..." & vbCrLf)
    End Sub 
End Class 
' The example diplays output similar to the following: 
'    Press any key, or 'X' to quit, or CTRL+C to interrupt the read operation: 
'     Key pressed: J 
'     
'    Press any key, or 'X' to quit, or CTRL+C to interrupt the read operation: 
'     Key pressed: Enter 
'     
'    Press any key, or 'X' to quit, or CTRL+C to interrupt the read operation: 
'     
'    The read operation has been interrupted. 
'     Key pressed: ControlC 
'     Cancel property: False 
'    Setting the Cancel property to true... 
'     Cancel property: True 
'    The read operation will resume... 
'     
'     Key pressed: Q 
'     
'    Press any key, or 'X' to quit, or CTRL+C to interrupt the read operation: 
'     Key pressed: X

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0
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