CODEWITHSUNDEEP
c#.netconsole
Shamim
Shamim

Reputation: 443

How to put some text in C# console instead of user typing it in?

In my C# console application, I prompt user to insert the ip address:

string strIpAddress;
Console.WriteLine("Type the IP Address:");
strIpAddress = Console.ReadLine();

Output looks like this:

enter image description here

I want to put the default IP address text ready on console for user to see and just hit the ENTER. If the default IP is invalid then user should be able to delete the text (with backspace), correct the IP address, then hit the ENTER. User should see something like this:

enter image description here

I don't know how to do this! ;-(

Thanks for any sugestion.

Upvotes: 5

Views: 5451

Answers (2)

user3598756
user3598756

Reputation: 29421

Edited to allow for user editing

Console.Write("Type the IP Address:\n");
SendKeys.SendWait("192.168.1.1"); //192.168.1.1 text will be editable :)
strIpAddress=Console.ReadLine();

This requires adding the System.Windows.Forms to the references and adding the namespace.

Upvotes: 5

Maximilian Gerhardt
Maximilian Gerhardt

Reputation: 5353

A more sophisticated example using Console.SetCursorPosition() to move the cursor to the left (if possible) and Console.ReadKey() to read the keys directly to intercept Backspace presses and enter keys:

using System;
using System.Linq;

namespace StackoverflowTests
{
    class Program
    {

        public static void Main(string[] args)
        {
            Console.WriteLine("Type the IP Address: ");
            //Put the default IP address 
            var defaultIP = "192.168.0.190";
            Console.Write(defaultIP);

            string input = defaultIP;
            //Loop through all the keys until an enter key
            while (true)
            {
                //read a key
                var key = Console.ReadKey(true);
                //Was this is a newline? 
                if (key.Key == ConsoleKey.Enter)
                {
                    Console.WriteLine();
                    break;
                }
                //Was is a backspace? 
                else if (key.Key == ConsoleKey.Backspace)
                {
                    //Did we delete too much?
                    if (Console.CursorLeft == 0)
                        continue; //suppress
                    //Put the cursor on character back
                    Console.SetCursorPosition(Console.CursorLeft - 1, Console.CursorTop);
                    //Delete it with a space
                    Console.Write(" ");
                    //Put it back again
                    Console.SetCursorPosition(Console.CursorLeft - 1, Console.CursorTop);
                    //Delete the last char of the input
                    input = string.Join("", input.Take(input.Length - 1));
                }
                //Regular key? add it to the input
                else if(char.IsLetterOrDigit(key.KeyChar))
                {
                    input += key.KeyChar.ToString();
                    Console.Write(key.KeyChar);
                } //else it must be another control code (ESC etc) or something.
            }

            Console.WriteLine("You entered: " + input);
            Console.ReadLine();
        }
    }
}

Can be made even more sophisticated if you want to add support for LeftArrow and RightArrow presses, or even UpArrow presses for recalling the last typed in stuff.

Upvotes: 4

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