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ConsoleCancelEventArgs.Cancel Property

Gets or sets a value that indicates whether simultaneously pressing the Control modifier key and the C console key (Ctrl+C) or the Ctrl+Break keys terminates the current process. The default is false, which terminates the current process.

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

public bool Cancel { get; set; }

Property Value

Type: System.Boolean
true if the current process should resume when the event handler concludes; false if the current process should terminate. The default value is false; the current process terminates when the event handler returns. If true, the current process continues.

The Cancel property is automatically initialized to false when the handler for the CancelKeyPress event is invoked. The value of the Cancel property when the event handler finishes determines whether the current process resumes or terminates.

In a set operation after Ctrl+C is pressed, specify true to indicate that the current process should resume when the event handler concludes, or false to indicate that the current process should terminate.

Notes to Callers

In the .NET Framework 3.5 and .NET Framework 4, attempting to set the Cancel property to true if the CancelKeyPress event was invoked by the user pressing Ctrl+Break threw an InvalidOperationException exception. In the .NET Framework 4.5, you can set the Cancel property to true after the user presses Ctrl+Break and cancel the termination of the application.

The following example demonstrates how to use the Cancel property to handle an event.

using System;

class Sample 
{
    public static void Main()
    {
        ConsoleKeyInfo cki;

        Console.Clear();

        // Establish an event handler to process key press events.
        Console.CancelKeyPress += new ConsoleCancelEventHandler(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}\n", cki.Key);

            // Exit if the user pressed the 'X' key. 
            if (cki.Key == ConsoleKey.X) break;
        }
    }

    protected static void myHandler(object sender, ConsoleCancelEventArgs args)
    {
        Console.WriteLine("\nThe read operation has been interrupted.");

        Console.WriteLine("  Key pressed: {0}", args.SpecialKey);

        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...\n");
    }
}
// The example displays output similar to the follwoing: 
//    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

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

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