I am creating a C# console application that will be performing an infinite process. How can I get the application to "pause" when the user presses the escape key?
Once the user presses the escape key I want the option to either exit the application or continue the loop right where it left off. I don't want any discontinuity in the process. If I press Esc at step 100 I should be able to pick right back up at step 101.
Here is my method so far:
// Runs the infinite loop application
public static void runLoop()
{
int count = 0;
while (Console.ReadKey().Key!= ConsoleKey.Escape)
{
WriteToConsole("Doing stuff.... Loop#" + count.ToString());
for (int step = 0; step <= int.MaxValue; step++ ) {
WriteToConsole("Performing step #" + step.ToString());
if (step == int.MaxValue)
{
step = 0; // Re-set the loop counter
}
}
count++;
}
WriteToConsole("Do you want to exit? y/n");
exitApplication(ReadFromConsole());
}
Is there any way to check for the user input key in a separate thread then pause the infinite loop when the other thread sees an Esc key-press?
To find out if there is a key available in the loop, you can do this:
while (someLoopCondition)
{
//Do lots of work here
if (Console.KeyAvailable)
{
var consoleKey = Console.ReadKey(true); //true keeps the key from
//being displayed in the console
if (consoleKey.Key == ConsoleKey.Escape)
{
//Pause here, ask a question, whatever.
}
}
}
Console.KeyAvailable returns true if there is a key in the input stream ready to read and it is a non-blocking call so it won't pause to wait for input. You can check if the escape key was pressed and pause or do whatever you want if the condition is true.
Ron, big thank you for your answer. Using Console.KeyAvalible was key to finding the exact solution to my issue. Here is what I did to produce the results I was expecting. I needed to add in a few methods to check if the user wants to break the current operation or start a new loop from the beginning.
public static void runUpdater()
{
int count = 0;
while (true)
{
WriteToConsole("Doing stuff.... Loop# " + count.ToString());
for (int step = 0; step <= int.MaxValue; step++)
{
if (!breakCurrentOperation())
{
WriteToConsole("Performing step #" + step.ToString());
if (step == int.MaxValue)
{
step = 0; // Re-set the loop counter
}
}
else
{
break;
}
}
count++;
if (!startNewOperation())
{
// Noop
}
else
{
break;
}
}
WriteToConsole("\nAre you ready to run the database updater again? y/n");
startApplication(ReadFromConsole());
}
public static bool startNewOperation()
{
WriteToConsole("Do you want go back to the main menu or start a new update process? \nType y to start a new update process or n to go to the main menu.");
string input = ReadFromConsole();
if (input == "y" || input == "Y")
{
return false;
}
else if (input == "n" || input == "N")
{
return true; // Noop - Restart the Loop from the begining
}
else
{
WriteToConsole("Error: Input was not recognized. ");
return startNewOperation(); // Recursivly call method untill user enters a logical input
}
}
public static bool breakCurrentOperation()
{
if (Console.KeyAvailable)
{
var consoleKey = Console.ReadKey(true);
if (consoleKey.Key == ConsoleKey.Escape)
{
WriteToConsole("Do you want to stop the current process? \nType s to stop or c to continue.");
string input = Console.ReadLine();
if (input == "c" || input == "C")
{
return false; // Continue
}
else if (input == "s" || input == "S")
{
return true; // Break the loop
}
else
{
WriteToConsole("Error: Input was not recognized, the current process will now continue. Press Esc to stop the operation.");
}
}
}
return false;
}
Here are the results:
Related
So I'm building this RPG turn based game for a class. I'm not trying to get my homework done for me, but this one problem is REALLY spinning me out, I've been at this for like 3 hours and I can't figure out how to fix this problem.
Essentially, I have an update method that controls whos turn it is (either the player or the computer)
public bool Update()
{
// clears console for a fresh start
Console.Clear();
//branch who's turn it is and add a line indicating so
if (playerTurn)
{
//print that it's the player's turn
Console.WriteLine("It's Your Turn to Attack!");
//run the player turn
PlayerTurn();
}
else
{
//print the rivals turn label
Console.WriteLine("It's the Enemy's Turn to Attack!");
}
//run the rivals turn
RivalsTurn();
{
}
//end game check
return EndTurn();
}
Then, I have the player turn method ---
void PlayerTurn()
{
// print instructions to select an attacker
Console.WriteLine($"Select which character will attack!\n(1) To Select {playerArray[0].Name()}\n(2) To Select {playerArray[1].Name()}\n(3) To Select {playerArray[2].Name()}\n(4) to view your teams current status\n(5) To Heal An Ally");
// Loop until an attacker is chosen
while (Attacker == null)
{
// use num 1-3 to select player party member that is the attacker
ConsoleKeyInfo k = Console.ReadKey();
if (k.KeyChar == '1')
{
Attacker = playerArray[0];
Console.WriteLine($"\nYou've chosen to attack with {Attacker.Name()}");
}
else if (k.KeyChar == '2')
{
Attacker = playerArray[1];
Console.WriteLine($"You've chosen to attack with {Attacker.Name()}");
}
else if (k.KeyChar == '3')
{
Attacker = playerArray[2];
Console.WriteLine($"You've chosen to attack with {Attacker.Name()}");
}
else if(k.KeyChar == '4')
{
PrintParties();
continue;
} else if (k.KeyChar == '5') {
HealAlly();
break;
}
// start a new line after user input
Console.WriteLine();
// Data Validation: make sure the key typed is a valid key
if (k.KeyChar < '1' || k.KeyChar > '5')
{
Console.WriteLine("Please Enter (1), (2), or (3) to select your attacking character. Press (4) to view your stats, and (5) to Heal an Ally");
continue;
}
else // convert from key input (1-3) to array element space (0-2)
curSelection = int.Parse(k.KeyChar.ToString()) - 1;
{
}
if (Attacker.GetHP() <= 0)
{
//check to make sure the selected character is alive HP > 0
//print the attackers name
//character's dead choose again
Console.WriteLine($"{Attacker.Name()} is dead! Choose someone who is alive!");
Console.WriteLine("Please Enter (1), (2), or (3) to select your attacking character. Press (4) to view your stats, and (5) to Heal an Ally");
Attacker = null;
}
else
{
Console.WriteLine($"{Attacker.Name()} will attack!");
Thread.Sleep(1000);
}
}
//print instructions for choosing a rival.
Console.WriteLine($"Select which enemy to attack!\n(1) To Attack {enemyArray[0].Name()}\n(2) To Attack {enemyArray[1].Name()}\n(3) To Attack {enemyArray[2].Name()}\n(4) To see the Enemies Current Stats.");
//loop until a defender is choosen
while (Defender == null)
{
// use 1-3 to select player party member that is the attacker
ConsoleKeyInfo k = Console.ReadKey();
if (k.KeyChar == '1')
{
Defender = enemyArray[0];
Console.WriteLine($"\nYou will attack {Defender.Name()}");
} else if(k.KeyChar == '2') {
Defender = enemyArray[1];
Console.WriteLine($"\nYou will attack {Defender.Name()}");
}
else if (k.KeyChar == '3')
{
Defender = enemyArray[2];
Console.WriteLine($"\nYou will attack {Defender.Name()}");
} else if (k.KeyChar == '4')
{
playerTurn = false;
PrintParties();
playerTurn = true;
}
{ }
//add a new line aft er the user input
Console.WriteLine();
// Data Validation: make sure the key typed is a valid key
if (k.KeyChar < '1' || k.KeyChar > '3')
{
// repeat instructions
Console.WriteLine("Select an enemy to attack by pressing either 1, 2, or 3.\n");
// loop again
continue;
}
else // convert from key input (1-3) to array element space (0-2)
curSelection = int.Parse(k.KeyChar.ToString()) - 1; //minus one to use as index
//check to make sure the selected character is alive HP > 0
//print the defenders name
//assign the selected character as the defender
if (Defender.GetHP() <= 0)
{
//print instructions again
Console.WriteLine($"{Defender.Name()} is already dead! Pick another enemy!");
Console.WriteLine("Select an enemy to attack by pressing either 1, 2, or 3.\n");
Defender = null;
} else
{
Console.WriteLine($"{Attacker.Name()} attacks {Defender.Name()}!");
Thread.Sleep(2000);
}
}
//damage the defender by the attacker's Strength value
Defender.ApplyDamage(Attacker.GetStrength());
//change color for rival team
Console.BackgroundColor = Attacker.GetTeamColor();
//print the new rival's health
Console.WriteLine($"{Defender.Name()} was hit by {Attacker.Name()}! {Defender.Name()} now only has {Defender.GetHP()} HP!");
EndTurn();
//change color back for normal
Console.BackgroundColor = ConsoleColor.Black;
//pause for 2 seconds
Thread.Sleep(2000);
//reset attacker/defender for next attack
Attacker = null;
Defender = null;
}
What I am trying to do is when the player selects "5" and runs the HealAlly() Method, I want the program to Take the users next input (who to heal), tell the player whether or not they can heal (if the character is either dead or full health) and then switch turns.
Instead, the code jumps back to the middle of the PlayerTurn method and tries to execute from there, but since the Attacker was never set (the user hit 5 so they didn't pick an Attacker) the game will crash.
Here is the HealAlly() method:
void HealAlly()
{
float healing = 3;
while (Healee == null)
{
Console.WriteLine("\nWhich Ally Do You Want To Heal?");
Console.WriteLine($"(1) for {playerArray[0].Name()}\n(2) for {playerArray[1].Name()}\n(3) for {playerArray[2].Name()}");
// use 1-3 to select player party member that is being healed
ConsoleKeyInfo k = Console.ReadKey();
if (k.KeyChar == '1')
{
Healee = playerArray[0];
Console.WriteLine($"\nYou will heal {Healee.Name()}");
Console.WriteLine("Healing...");
}
else if (k.KeyChar == '2')
{
Healee = playerArray[1];
Console.WriteLine($"\nYou will heal {Healee.Name()}");
Console.WriteLine("Healing...");
}
else if (k.KeyChar == '3')
{
Healee = playerArray[2];
Console.WriteLine($"\nYou will heal {Healee.Name()}");
Thread.Sleep(1000);
Console.WriteLine("Healing...");
}
else if (k.KeyChar > 3 || k.KeyChar < 1)
{
Console.WriteLine("Choose which character you want to heal!");
continue;
}
if (Healee.GetHP() >= 12)
{
Thread.Sleep(1000);
Console.WriteLine($"{Healee.Name()} has full health! You can't heal them!");
EndTurn();
}
else if (Healee.GetHP() <= 0)
{
Thread.Sleep(1000);
Console.WriteLine($"{Healee.Name()} is dead! You can't heal them!");
EndTurn();
}
else
{
Healee.ApplyHealing(healing);
Thread.Sleep(2000);
Console.WriteLine($"{Healee.Name()} has been healed, and now has {Healee.GetHP()} HP!");
EndTurn();
}
I thought that adding the call to EndTurn() at the end of the HealAlly() method would cause the turn to end, but instead all it does is give me the delay message and then shoot back to the middle of the PlayerTurn() method. I'm sure it's because there was no Attacker set, but that's not what I want, because I don't want the player to be able to attack after healing.
Here is the EndTurn() method if that will help
bool EndTurn()
{
//switch turns for next loop
playerTurn = !playerTurn;
// loop through players to see if they're alive and store in a variable counting if they're alive or not
bool playersAlive = true;
for (int i = 0; i < playerArray.Length; i++)
{
if (playerArray[0].GetHP() <= 0 && playerArray[1].GetHP() <= 0 && playerArray[2].GetHP() <= 0)
{
playersAlive = false;
}
}
// same for rivals
bool rivalsAlive = true;
for (int i = 0; i < enemyArray.Length; i++)
{
if (enemyArray[0].GetHP() <= 0 && enemyArray[1].GetHP() <= 0 && enemyArray[2].GetHP() <= 0)
{
rivalsAlive = false;
}
}
// if both have things alive start the next round, pause the game, and return true to continue playing
if (playersAlive && rivalsAlive)
{
Console.WriteLine("Next Round Starts in 5 seconds");
Thread.Sleep(5000);
return true;
} // if only the players have members alive you win
else if (playersAlive)
{
//clear screen for results
Console.Clear();
//print you've won and parties
Console.WriteLine("Congrats you win! Final Standings:");
playerTurn = false;
PrintParties();
playerTurn = true;
PrintParties();
Thread.Sleep(5000);
Console.WriteLine("Thanks For Playing!");
Console.WriteLine("Press Any Key to Play Again");
Console.ReadKey();
Console.Clear();
Init();
return false;
} // only rival members are alive
else
{
//clear screen for results
Console.Clear();
//Print you've lost and parties
Console.WriteLine("You Lose :( Final Standings:");
playerTurn = false;
PrintParties();
playerTurn = true;
PrintParties();
Thread.Sleep(5000);
Console.WriteLine("Thanks For Playing!");
Console.WriteLine("Press Any Key to Play Again");
Console.ReadKey();
Console.Clear();
Init();
return false;
}
}
This is bugging me, can anyone help?
void PlayerTurn()
{
// ...
while (Attacker == null)
{
// ...
if (k.KeyChar == '5') {
HealAlly();
break;
}
}
// ...code that depends on Attacker...
}
The break statement here only causes the flow to break out of the while loop and continue with the code the depends on Attacker. If you want to leave the PlayerTurn() method altogether, replace the break; with a return;
To give some context for the code, I'm modifying the game "AssaultCube".
So this is a console program. When it launches, you can type stuff in and if you type in "1", it'll start setting the health value to 999 in a loop. However, you can't type more stuff in because the loop isn't over, but in order to end the loop, I need to be able to type "1" to toggle it off. I want to be able to toggle this on and off each time I type in "1". It seems like a simple problem and I've been trying to get this to work for hours with no luck and my brain is fried. Thanks in advance and sorry if I was unclear in my explanation, I'm not good at those :D.
while (true)
{
string Select;
Select = Console.ReadLine();
if (Select == "1") //If the number "1" is typed, do stuff
{
int finalHealth = localPLayer + health; //Add the Base and Health addresses together
if (healthToggle == false)
{
healthToggle = true;
Console.WriteLine("\n[1] Unlimited Health activated\n");
while (healthToggle) //While Health Toggle is TRUE, do stuff
{
vam.WriteInt32((IntPtr)finalHealth, 999); //Set finalHealth to 999 in a loop, making you invincible
Thread.Sleep(100); //Let CPU rest
}
}
else
{
healthToggle = false;
Console.WriteLine("\n[1] Unlimited Health deactivated\n");
vam.WriteInt32((IntPtr)finalHealth, 100); //Set health value back to normal
}
}
Thread.Sleep(100);
}
I agree with 41686d6564, Console.KeyAvailable and Console.ReadKey() are definitely the way to go.
Try this out...
static void Main(string[] args)
{
bool quit = false;
while (!quit)
{
Console.WriteLine("Press Esc to quit, or 1 to start/stop.");
while (!Console.KeyAvailable)
{
System.Threading.Thread.Sleep(100);
}
ConsoleKeyInfo cki = Console.ReadKey(true);
if (cki.Key == ConsoleKey.Escape)
{
quit = true;
}
else if (cki.Key == ConsoleKey.D1)
{
Console.WriteLine("\n[1] Unlimited Health activated\n");
bool godMode = true;
while (godMode)
{
// ... do something ...
Console.WriteLine(DateTime.Now.ToString("HH:mm:ss.ffff") + ": ...something ...");
System.Threading.Thread.Sleep(100);
if (Console.KeyAvailable)
{
cki = Console.ReadKey(true);
if (cki.Key == ConsoleKey.D1)
{
godMode = false;
}
}
}
Console.WriteLine("\n[1] Unlimited Health deactivated\n");
}
}
Console.WriteLine("Goodbye!");
Console.Write("Press Enter to Quit");
Console.ReadLine();
}
If i use readline() i could not use readkey(); to avoid read twice
Console.Write("Your selection is: ");
bSelAns = int.TryParse(Console.ReadLine(), out iSelection);
string ans =iSelection.ToString();
i do readline here so i try to avoid readkey();
ConsoleKey keychar ;
keychar = ConsoleKey.Q;
string y = "q";
I need to bool exit when i enter q;
if (bSelAns ==false)
{
if (ans == y)
{
break;
}
Console.WriteLine("You have entered an invalid strinng, please enter a number or string from the list.\n");
}
Sorry, I think I misunderstood what you were looking for.
So I guess what you want is to be able to use ReadKey and Readline together?
that is impossible as ReadKey end after the first char, and readLine will end when Enter is pressed.. however, you could make ReadKey act as a ReadLine, and then you can check if Q is pressed for each keypress.
to do that you need a buffer, that saves all keypresses, and each time 'Enter' is pressed, it empties the Buffer to the screen.
Edit: Logic for 'Enter' changed to reset if pressed, even if the buffer is empty
Edit2: Added Comments
using System;
class Program
{
public static void Main(string[] args){
var buffer = "";
while(true){
//Only show if buffer is empty
if(buffer.Length == 0){
Console.WriteLine("enter key:");
}
var key = Console.ReadKey(false);
//Only Exit if buffer is empty and Q is pressed (if Q is the first Key pressed)
if(buffer.Length == 0 && key.Key == ConsoleKey.Q){
Console.WriteLine();
Console.WriteLine("the key was 'Q' goodbye");
return;
}
//Every time Enter is pressed, Use and Flush the buffer
else if(key.Key == ConsoleKey.Enter)
{
if(buffer.Length > 0){
Console.WriteLine();
Console.WriteLine("buffer have {0}", buffer);
if(int.TryParse(buffer, out int number)){
Console.WriteLine("{0} is a number!", number);
}
}
buffer = "";
}
//else will capture everything else pressed, and add it to buffer
else{
buffer += key.KeyChar;
}
}
}
}
Now here is the situation we are in:
getinput:
//things happen here
string typed = Console.ReadLine();
try
if (typed == "com")
{
//things happen here
}
else if (Console.ReadKey(true).Key == (ConsoleKey.F1) + (ConsoleModifiers.Alt))
{
System.Environment.Exit(0);
}
//other else if's happen here
else
{
Console.WriteLine("\n" + typed + " isn't an option.");
goto getInput;
}
}
catch (Exception)
{
}
goto getInput;
what i want to do with this is when i press alt+f1 the program will terminate itself however because the program waits for some input from me to write even with the working version (without the alt part) it wants me to type the things then press enter, which i dont want. how does one handlde this??
static void Main(string[] args)
{
Console.TreatControlCAsInput = true;
var typed = ReadLine();
if (typed == "com")
{
Console.WriteLine("com");
//things happen here
}
//other else if's happen here
else
{
Console.WriteLine("\n" + typed + " isn't an option.");
}
}
public static string ReadLine() {
StringBuilder sb = new StringBuilder();
do
{
ConsoleKeyInfo key = Console.ReadKey();
if ((key.Modifiers & ConsoleModifiers.Alt) != 0)
{
if (key.Key == ConsoleKey.K)
{
Console.WriteLine("killing console");
System.Environment.Exit(0);
}
}
else
{
sb.Append(key.KeyChar);
if (key.KeyChar == '\n'||key.Key==ConsoleKey.Enter)
{
return sb.ToString();
}
}
} while (true);
}
that code will help you with your problem,
just be aware that when you reading a line by char's you will need to handle things like backspace
First of all, please consider using loops instead of goto, as gotos are dangerous. Why? Have a look here: 'Goto' is this bad?
To solve your problem you can use the ConsoleKeyInfo class in combination with the Console.ReadKey() method to get information about single key presses. With this you can check for any key-combination right before adding up the single characters to a string. A working example could look like:
namespace Stackoverflow
{
using System;
class Program
{
public static void Main(string[] args)
{
ConsoleKeyInfo keyInfo = default(ConsoleKeyInfo);
string input = string.Empty;
// loop while condition is true
while (true)
{
// read input character-wise as long as user presses 'Enter' or 'Alt+F1'
while (true)
{
// read a single character and print it to console
keyInfo = Console.ReadKey(false);
// check for close-combination
if (keyInfo.Key == ConsoleKey.F1 && (keyInfo.Modifiers & ConsoleModifiers.Alt) != 0)
{
// program terminates
Environment.Exit(0);
}
// check for enter-press
if (keyInfo.Key == ConsoleKey.Enter)
{
// break out of the loop without adding '\r' to the input string
break;
}
// add up input-string
input += keyInfo.KeyChar;
}
// optional: enter was pressed - add a new line
Console.WriteLine();
// user pressed enter, do something with the input
try
{
if (input == "com")
{
// right option - do something
}
else
{
// wrong option - reset ConsoleKeyInfo + input
Console.WriteLine("\n" + input + " isn't an option.");
keyInfo = default(ConsoleKeyInfo);
input = string.Empty;
continue;
}
}
catch (Exception)
{
// handle exceptions
}
}
}
}
}
I want to constantly wait for a key combination to be pressed in my console application, but the way I am currently doing it seems to use a lot of CPU while the process is running.
For such a basic task it feels like there should be a better way to do this, but I'm unsure of what that is, I profiled my application with dotTrace and found that the only hot spot was this code below.
while (true)
{
if (!Console.KeyAvailable)
{
continue;
}
var input = Console.ReadKey(true);
if (input.Modifiers != ConsoleModifiers.Control)
{
continue;
}
if (input.Key == ConsoleKey.S)
{
Server?.Dispose();
}
}
If you are fine using standard Ctrl+C for exit instead of Ctrl+S you can use simple ReadKey. And make sure TreatControlCAsInput is set, oterwise, the application will just be killed.
static void Main(string[] args)
{
// important!!!
Console.TreatControlCAsInput = true;
while (true)
{
Console.WriteLine("Use CTRL+C to exit");
var input = Console.ReadKey();
if (input.Key == ConsoleKey.C && input.Modifiers == ConsoleModifiers.Control)
{
break;
}
}
// Cleanup
// Server?.Dispose();
}
Instead of watching this in a loop, use the keypress event to check each time a key is pressed.
This means you only check once for each key press.
Edit:
I missed the console app part but you can read the line like this:
from: https://www.dotnetperls.com/console-readline
using System;
class Program
{
static void Main()
{
while (true) // Loop indefinitely
{
Console.WriteLine("Enter input:"); // Prompt
string line = Console.ReadLine(); // Get string from user
if (line == "exit") // Check string
{
break;
}
Console.Write("You typed "); // Report output
Console.Write(line.Length);
Console.WriteLine(" character(s)");
}
}
}
No busy waiting is needed. Console.ReadKey() will block until there is a key press available, with basically no CPU usage. Thus, you don't need to check Console.KeyAvailable over and over again.
while (true)
{
// DO NOT INTERCEPT KEY PRESSES!
//IF CTRL+S IS FORWARDED TO THE CONSOLE APP, WEIRD THINGS WILL HAPPEN.
var input = Console.ReadKey(false);
if (input.Modifiers != ConsoleModifiers.Control)
{
continue;
}
if (input.Key == ConsoleKey.S)
{
Server?.Dispose();
}
}
I think you should use Thread.Sleep
while (true)
{
Thread.Sleep(100);
if (!Console.KeyAvailable)
{
continue;
}
var input = Console.ReadKey(true);
if (input.Modifiers != ConsoleModifiers.Control)
{
continue;
}
if (input.Key == ConsoleKey.S)
{
Server?.Dispose();
}
}
You only need this before finish Main(string[] args)
private static void Main(string[] args)
{
//call method for daemon before while
while (true)
{
Thread.Sleep(1000);
}
}