question

BrandonStewart-4522 avatar image
0 Votes"
BrandonStewart-4522 asked karenpayneoregon answered

Has Microsoft ever considered adding a Pause() method to the Console class for VB/C#?

Has Microsoft ever considered adding a Pause() method to the Console class for VB/C# .NET like that in the following code?
Yes, I know the user can use the following code to create a subroutine, but it would be super-super nice if this were an actual part of the class.

 Private Const m_STR_PMPT As System.String = "Please press the [Enter] key to continue . . . " 'Default user prompt.
        
     Public Sub Pause(Optional Prompt As System.String = m_STR_PMPT, Optional ResumeInterval As System.Int64 = 0)
        Try 'Attempt the following block(s) of code.
           Dim r_hProc As New System.Diagnostics.Process 'An instance of a local system process.
           Dim r_hInfo As New System.Diagnostics.ProcessStartInfo("cmd") 'An instance of the process' StartInfo() property.
        
           Console.Write(Environment.NewLine & Prompt) 'Display the user prompt.
        
           If ResumeInterval <= 0 Then 'If the user did not specify a valid timer value.
              With r_hInfo 'Regarding the process start information object.
                 .Arguments = " /C pause >nul" 'Pass the argument to pause the process.
                 .UseShellExecute = False 'Indicate the process is not to be executed via the OS shell.
                 .WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden 'Hide the process' window.
              End With
           Else 'If the user specified a valid timer value.
              With r_hInfo 'Regarding the process start information object.
                 .Arguments = " /C timeout /t " & ResumeInterval & " >nul" 'Pass the argument to pause the process along with a timer value. {>nul} suppresses the console's built-in user prompt.
                 .UseShellExecute = False 'Indicate the process is not to be executed via the OS shell.
                 .WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden 'Hide the process' window.
              End With
           End If
            
           With r_hProc 'Regarding the process object.
              .StartInfo = r_hInfo 'Get the start information for the process.
           End With
            
           r_hProc.Start() 'Start the process.
           r_hProc.WaitForExit() 'Instruct the process component to wait for the associated process to exit.
           r_hProc.Close() 'Free all resources associated with the process.
            
           r_hInfo = Nothing 'Destroy the process start information object.
           r_hProc.Dispose() 'Deinitialize the process object.
           r_hProc = Nothing 'Destroy the process object.
        Catch r_eRntm As System.Exception 'Trap any unexpected errors.
           ' DO ERROR HANDLING HERE
        End Try
     End Sub

An optional timer argument is included to allow the programmer to resume execution of the process if the user doesn't press a key. It is a very handy method for many console applications and not just for tutorials or testing. It is especially handy when you want to convey a message here and there to a user without terminating the program.

dotnet-runtime
· 2
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Hi @BrandonStewart-4522 ,

It is a very handy method for many console applications and not just for tutorials or testing.

You can consider requesting a feature on developer community forum.


0 Votes 0 ·

The developer community banned me.

0 Votes 0 ·
cheong00 avatar image
0 Votes"
cheong00 answered cheong00 edited

You mean something like this?

     static void Pause(int waitinmillsec, string promptText = "Press a key to continue...")
     {
         Console.WriteLine(promptText);
         try
         {
             Thread t = new Thread(x => Console.ReadKey());
             t.Start();
             t.Join(waitinmillsec);
         }
         catch (ThreadAbortException)
         {

         }
     }

Usage:

             Console.WriteLine("Some information");
    
             Pause(5000, "Press any key or let me rest for 5 seconds...");
    
             Console.WriteLine("Some other information");
· 3
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I can't seem to figure out how to translate the following line to Visual Basic:

 Thread t = new Thread(x => Console.ReadKey());

I attempted this line in VB but it doesn't work for me:

  Dim t As New Thread(x >= Console.ReadKey())

I can't figure out what data type 'x' is supposed to be. Also, my Visual Studio IDE automatically changes your '=>' to '>='.

How do I make this line work in VB?



0 Votes 0 ·
cheong00 avatar image cheong00 BrandonStewart-4522 ·

That's lambda expression syntax in C#. I'm trying to create an anonymous function that the only statement inside is Console.ReadKey()

To create equivalent function in VB.NET:

 Imports System.Threading
    
 Module Module1
    
     Sub Main()
         Console.WriteLine("Some information")
         Pause(5000, "Press any key or let me rest for 5 seconds...")
         Console.WriteLine("Some other information")
     End Sub
    
     Sub Pause(ByVal waitinmillsec As Int32, Optional ByVal promptText As String = "Press a key to continue...")
         Console.WriteLine(promptText)
         Try
             Dim t As New Thread(Function(x) Console.ReadKey())
             t.Start()
             t.Join(waitinmillsec)
         Catch tae As ThreadAbortException
    
         End Try
    
     End Sub
    
 End Module
0 Votes 0 ·

The x there has type of Object and the purpose is to make the compiler match the signature to ParameterizedThreadStart. If I don't add it there, it will complain that it cannot figure out "which kind of parameter in the constructor of Thread" the lambda should be converted to, and I'll have to write it as the following:

 Dim t As New Thread(New ThreadStart(Function() Console.ReadKey()))

More about Lambda Expressions:
C#: https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/operators/lambda-expressions
VB.NET: https://docs.microsoft.com/en-us/dotnet/visual-basic/programming-guide/language-features/procedures/lambda-expressions



0 Votes 0 ·
karenpayneoregon avatar image
0 Votes"
karenpayneoregon answered

Here is another idea, it's written in C# and usable for both C# and VB.NET. Create a new C# Class project and add the following class.

 using System;
 using System.Threading.Tasks;
 using static System.Console;
    
 namespace ConsoleHelpers
 {
     public static class ConsoleKeysHelper
     {
         public static void WaitReadLine(string message = "Press any key to terminate.")
         {
             WriteSectionBold(message,false);
             Console.ReadLine();
         }
    
         public static void WriteSectionBold(string message, bool line = true)
         {
             var originalForeColor = ForegroundColor;
    
             ForegroundColor = ConsoleColor.White;
             WriteLine(message);
             ForegroundColor = originalForeColor;
             if (line)
             {
                 WriteLine(new string('-', 100));
             }
    
         }        
    
         /// <summary>
         /// Provides an enhanced Console.ReadLine with a time out.
         /// </summary>
         /// <param name="timeout">Timeout</param>
         /// <param name="message">Optional text to display</param>
         /// <returns>Input from a Task or if no input an empty string</returns>
         /// <remarks>
         /// Example, wait for two seconds and a half
         /// ConsoleReadLineWithTimeout(TimeSpan.FromSeconds(2.5))
         /// 
         /// Example, use default, wait for one second
         /// ConsoleReadLineWithTimeout(TimeSpan.FromSeconds())
         /// </remarks>
         public static string ReadLineWithTimeout(TimeSpan? timeout = null, string message = "")
         {
             if (!string.IsNullOrWhiteSpace(message))
             {
                 WriteSectionBold(message, false);
             }
                
             TimeSpan timeSpan = timeout ?? TimeSpan.FromSeconds(1);
             var task = Task.Factory.StartNew(Console.ReadLine);
             var result = (Task.WaitAny(new Task[] { task }, timeSpan) == 0) ? task.Result : string.Empty;
    
             return result;
    
         }
         /// <summary>
         /// Read line with timeout and optional message
         /// </summary>
         /// <param name="seconds"></param>
         /// <param name="message"></param>
         /// <returns></returns>
         public static string ReadLineWithTimeout(int seconds, string message = "")
         {
             if (!string.IsNullOrWhiteSpace(message))
             {
                 WriteSectionBold(message, false);
             }
    
             TimeSpan timeSpan = TimeSpan.FromSeconds(seconds);
             var task = Task.Factory.StartNew(Console.ReadLine);
                
             var result = (Task.WaitAny(new Task[] { task }, timeSpan) == 0) ? task.Result : string.Empty;
    
             return result;
    
         }
    
         public static string ReadLineFiveSeconds(string message = "") => ReadLineWithTimeout(5, message);
         public static string PauseFiveSeconds(string message = "") => ReadLineWithTimeout(5, message);
            
         public static string ReadLineTenSeconds(string message = "") => ReadLineWithTimeout(10, message);
         public static string PauseTenSeconds(string message = "") => ReadLineWithTimeout(10, message);
     }
 }

Add a reference to a VB.NET for the above to a Console project and use

 Module Program
     Sub Main(args As String())
         Dim value = ReadLineFiveSeconds("Please enter your name within the next 5 seconds.")
         Console.WriteLine(value)
     End Sub
 End Module

For C#

 class Program
 {
     static void Main(string[] args)
     {
         var value = ReadLineFiveSeconds( "Please enter your name within the next 5 seconds.");
         Console.WriteLine(value);
     }
 }


Both support

 static void Main(string[] args)
 {
     var value = ReadLineWithTimeout(5, "Please enter your name within the next 5 seconds.");
     Console.WriteLine(value);
 }


I have full source code for the class project with more goodies.

Note if this was C# we could also have a async Main and use

 Console.WriteLine("Enter some text");
 var task = Task.Factory.StartNew(Console.ReadLine);
 var completedTask = await Task.WhenAny(task, Task.Delay(TimeSpan.FromSeconds(5)));
 var result = ReferenceEquals(task, completedTask) ? task.Result : string.Empty;
 Console.WriteLine(result);



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