Console.Treatcontrolcasinput Property In C#

In this article, you will learn about the Console.TreatControlCAsInput property in C# with its syntax, parameters, and examples.

What is Console.TreatControlCAsInput Property?

The property "Console.TreatControlCAsInput" may acquire or modify a value indicating whether the operating system interprets the Control modifier key and C console key (Ctrl+C) combination as ordinary input or as an interruption.

Syntax:

It has the following syntax:

public static bool TreatControlCAsInput { get; set; }

Property Value: When Ctrl+C is interpreted as regular input, this property yields a true value. If it is false, the program terminates if the input is Ctrl+C. This property will raise an IOException if the program cannot get or modify the console input buffer's input mode.

Functionality:

• ✅ Default Behaviour: Ctrl+C is interpreted as an interrupt signal by default when TreatControlCAsInput is set to false. Accordingly, the application terminates when you press Ctrl+C.
• ✅ Custom Behaviour: When TreatControlCAsInput is set to true, the key combination Ctrl+C is interpreted as standard input. It enables programmers to implement custom logic to handle the Ctrl+C shortcut, such as treating it like a command shortcut or ignoring it altogether.
• ✅ Control Flow: Modifying TreatControlCAsInput impacts the application's control flow. While setting it to false relies on the application terminating by default, setting it to true allows the application to handle Ctrl+C explicitly within its input processing logic.

Behaviour:

• ✅ True: Ctrl+C is regarded as standard input when this setting is applied. It indicates that Ctrl+C may be handled by the application's main loop, just like any other key press.
• ✅ False: Ctrl+C functions as an interrupt signal when it set to false. As with pressing the close button or sending a SIGINT signal in Unix-like systems, this results in the application terminating instantly.

I. Console.TreatControlCAsInput set to 'true'

Example-1:

Let us take an example to illustrate the Console.TreatControlCAsInput property when it is set to true in C#.

using System;
class Demo
{
    static void Main(string[] args)
    {
        Console.WriteLine("Ctrl+C will be treated as input.");        
        // TreatControlCAsInput should be set to 'true'.
        Console.TreatControlCAsInput = true;
        Console.WriteLine("Press Ctrl+C to test:");
        while (true)
        {
            ConsoleKeyInfo q = Console.ReadKey(true);
            if (q.Modifiers == ConsoleModifiers.Control && q.Key == ConsoleKey.C)
            {
                Console.WriteLine("You pressed Ctrl+C.");
                // Additional handling for Ctrl+C as input if needed
            }
            else
            {
                Console.WriteLine("You pressed the key is: " + q.KeyChar);
            }
        }
    }
}

Output:

Ctrl+C will be treated as input.
Press Ctrl+C to test:
e r s
You pressed the key is: e
You pressed the key is:  
You pressed the key is: r
You pressed the key is:  
You pressed the key is: s
You pressed the key is:

Explanation:

In this case, Ctrl+C will be handled as ordinary input because of Console.TreatControlCAsInput is set to true. Pressing Ctrl+C will cause the program to print a message but won't terminate.

Example-2:

Let us take another example to illustrate the Console.TreatControlCAsInput property when it is set to true in C#.

using System;
class Demo 
{
	static void Main()
	{
		ConsoleKeyInfo q;
		Console.TreatControlCAsInput = true;
		Console.WriteLine("Press any key with combination of ALT, "+
					"CTL, and Press the Esc to quit or SHIFT: \n");
		do {
			q = Console.ReadKey();
			Console.Write("You pressed the key is: ");
			if ((q.Modifiers & ConsoleModifiers.Shift) != 0)
				Console.Write("SHIFT + ");
			if ((q.Modifiers & ConsoleModifiers.Control) != 0)
				Console.Write("CTRL + ");
			if ((q.Modifiers & ConsoleModifiers.Alt) != 0)
				Console.Write("ALT + ");
			Console.WriteLine(q.Key.ToString());
		} while (q.Key != ConsoleKey.Escape);
	}
}

Output:

Press any key with a combination of ALT and CTL, and Press the Esc to quit or SHIFT: 
D
You pressed the key is: SHIFT + D
You pressed the key is: Enter
S
You pressed the key is: SHIFT + S
You pressed the key is: Enter
a
You pressed the key is: A
You pressed the key is: Enter

Explanation:

With the help of this program, it is easy to recognize and display pressed keys along with modifier keys like SHIFT, CTRL , and ALT . It demonstrates how to use the Console.TreatControlCAsInput property by treating Ctrl+C as regular input.

II. Console.TreatControlCAsInput set to 'false'

Example:

Let us take another example to illustrate the Console.TreatControlCAsInput property when it is set to false in C#.

using System;
class Demo
{
    static void Main(string[] args)
    {
        Console.WriteLine("Ctrl+C will be treated as interrupt.");
        // TreatControlCAsInput should be set to 'false'.
        Console.TreatControlCAsInput = false;
        Console.WriteLine("Press Ctrl+C to test:");
        while (true)
        {
            ConsoleKeyInfo q = Console.ReadKey(true);
            if (q.Modifiers == ConsoleModifiers.Control && q.Key == ConsoleKey.C)
            {
                Console.WriteLine("Ctrl+C is treated as interrupt. Exiting...");
                break;
            }
            else
            {
                Console.WriteLine("You pressed the key is: " + q.KeyChar);
            }
        }
    }
}

Output:

Ctrl+C will be treated as an interrupt.
Press Ctrl+C to test:n g k s
You pressed the key is: n
You pressed the key is:  
You pressed the key is: g
You pressed the key is:  
You pressed the key is: k
You pressed the key is:  
You pressed the key is: s
You pressed the key is:

Explanation:

In this example, Ctrl+C will be interpreted as an interrupt signal because the Console.TreatControlCAsInput is set to false. When Ctrl+C is pressed, the program will print a message and exit.