Console.CancelKeyPress Console.CancelKeyPress Console.CancelKeyPress Console.CancelKeyPress Event

Definition

Tritt ein, wenn die Control-Modifizierertaste (STRG) und entweder die C-Konsolentaste (c) oder die UNTBR-TASTE gleichzeitig gedrückt werden (STRG+C oder STRG+UNTBR).Occurs when the Control modifier key (Ctrl) and either the C console key (C) or the Break key are pressed simultaneously (Ctrl+C or Ctrl+Break).

public:
 static event ConsoleCancelEventHandler ^ CancelKeyPress;
public static event ConsoleCancelEventHandler CancelKeyPress;
member this.CancelKeyPress : ConsoleCancelEventHandler 
Public Shared Custom Event CancelKeyPress As ConsoleCancelEventHandler 

Beispiele

Im folgende Beispiel wird veranschaulicht, wie die CancelKeyPress Ereignis verwendet wird.The following example demonstrates how the CancelKeyPress event is used. Der Lesevorgang wird unterbrochen, wenn Sie STRG + C drücken, und die myHandler Ereignishandler aufgerufen.When you press Ctrl+C, the read operation is interrupted and the myHandler event handler is invoked. Bei der Eingabe an den Ereignishandler der ConsoleCancelEventArgs.Cancel Eigenschaft false, d. h., die der aktuelle Vorgang beendet wird, wenn der Ereignishandler beendet.Upon entry to the event handler, the ConsoleCancelEventArgs.Cancel property is false, which means that the current process will terminate when the event handler terminates. Der Ereignishandler wird jedoch die ConsoleCancelEventArgs.Cancel Eigenschaft, um true, welche bedeutet, dass der Prozess nicht beendet, und der Lesevorgang wird fortgesetzt.However, the event handler sets the ConsoleCancelEventArgs.Cancel property to true, which means that the process will not terminate and the read operation will resume.

using namespace System;

void OnCancelKeyPressed(Object^ sender, 
    ConsoleCancelEventArgs^ args)
{
    Console::WriteLine("{0}The read operation has been interrupted.",
        Environment::NewLine);

    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...{0}",
        Environment::NewLine);
}

int main()
{       
    // Clear the screen.
    Console::Clear();

    // Establish an event handler to process key press events.
    Console::CancelKeyPress += 
        gcnew ConsoleCancelEventHandler(OnCancelKeyPressed);

    while (true)
    {
        // Prompt the user.
        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.
        ConsoleKeyInfo^ keyInfo = Console::ReadKey(true);

        // Announce the name of the key that was pressed .
        Console::WriteLine("  Key pressed: {0}{1}", keyInfo->Key, 
            Environment::NewLine);

        // Exit if the user pressed the 'X' key.
        if (keyInfo->Key == ConsoleKey::X)
        {
            break;
        }
    }
}
// The example displays 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
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
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

    Protected Shared Sub myHandler(ByVal sender As Object, _
                                   ByVal args As ConsoleCancelEventArgs) 
        Console.WriteLine(vbCrLf & "The 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..." & 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

Hinweise

Dieses Ereignis wird verwendet, in Verbindung mit System.ConsoleCancelEventHandler und System.ConsoleCancelEventArgs.This event is used in conjunction with System.ConsoleCancelEventHandler and System.ConsoleCancelEventArgs. Die CancelKeyPress Ereignis können Sie eine Konsolenanwendung, die das STRG + C-Signal abfangen, damit der Ereignishandler, ob entscheiden kann Sie fortgesetzt oder beendet.The CancelKeyPress event enables a console application to intercept the Ctrl+C signal so the event handler can decide whether to continue executing or terminate. Weitere Informationen zur Behandlung von Ereignissen finden Sie unter behandeln und Auslösen von Ereignissen.For more information about handling events, see Handling and Raising Events.

Wenn der Benutzer entweder STRG + C oder STRG + UNTBR, drückt die CancelKeyPress Ereignis wird ausgelöst, und der Anwendung ConsoleCancelEventHandler -Ereignishandler ausgeführt wird.When the user presses either Ctrl+C or Ctrl+Break, the CancelKeyPress event is fired and the application's ConsoleCancelEventHandler event handler is executed. Der Ereignishandler übergeben wird eine ConsoleCancelEventArgs Objekt, das zwei nützliche Eigenschaften verfügt:The event handler is passed a ConsoleCancelEventArgs object that has two useful properties:

  • SpecialKey, wodurch Sie bestimmen, ob der Handler aufgerufen wurde, weil der Benutzer durch Drücken von STRG + C (der Eigenschaftswert ist ConsoleSpecialKey.ControlC) oder STRG + UNTBR (der Eigenschaftswert ist ConsoleSpecialKey.ControlBreak).SpecialKey, which allows you to determine whether the handler was invoked as a result of the user pressing Ctrl+C (the property value is ConsoleSpecialKey.ControlC) or Ctrl+Break (the property value is ConsoleSpecialKey.ControlBreak).

  • Cancel, wodurch Sie bestimmen, wie für Ihre Anwendung sollte auf den Benutzer reagieren Drücken von STRG + C oder STRG + UNTBR.Cancel, which allows you to determine how to your application should respond to the user pressing Ctrl+C or Ctrl+Break. In der Standardeinstellung die Cancel Eigenschaft false, die bewirkt, dass die programmausführung zu beenden, wenn der Ereignishandler beendet.By default, the Cancel property is false, which causes program execution to terminate when the event handler exits. Ändern die-Eigenschaft auf true gibt an, dass die Anwendung weiterhin ausgeführt werden sollte.Changing its property to true specifies that the application should continue to execute.

Tipp

Wenn Ihre Anwendung auf einfache Anforderungen verfügt, können Sie mithilfe der TreatControlCAsInput -Eigenschaft anstelle dieses Ereignis.If your application has simple requirements, you can use the TreatControlCAsInput property instead of this event. Durch Festlegen dieser Eigenschaft auf false, können Sie sicherstellen, dass Ihre Anwendung immer beendet wird, wenn der Benutzer STRG + C drückt.By setting this property to false, you can ensure that your application always exits if the user presses Ctrl+C. Durch Festlegung auf true, können Sie sicherstellen, dass die Anwendung nicht durch Drücken von STRG + C beendet wird.By setting it to true, you can ensure that pressing Ctrl+C will not terminate the application.

Der Ereignishandler für dieses Ereignis wird auf einem Threadpoolthread ausgeführt.The event handler for this event is executed on a thread pool thread.

Sicherheit

UIPermission
zum Ändern von sicheren übergeordnete und untergeordnete Fenster.for modifying safe top-level windows and subwindows. Zugeordnete Enumeration: SafeTopLevelWindowsAssociated enumeration: SafeTopLevelWindows

Gilt für:

Siehe auch