Console Input in a VB.Net Forms program works EXCEPT write and writeline don't display.

Question

See code below. Everything works as far as opening, reading and closing the console. The write and writeline do not output to be displayed.

Public Class Form1
    <System.Runtime.InteropServices.DllImportAttribute("kernel32.dll", EntryPoint:="AllocConsole")>
    Private Shared Function AllocConsole() As <System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.Bool)> Boolean
    End Function


    <System.Runtime.InteropServices.DllImportAttribute("kernel32.dll", EntryPoint:="FreeConsole")>
    Private Shared Function FreeConsole() As <System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.Bool)> Boolean
    End Function

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        getpassword()
    End Sub

 Private Sub getpassword()
        AllocConsole()
        Console.Write("Here I am! ")
        Console.WriteLine("Hello World!")
        Console.WriteLine("Enter Password:  ")
        Dim name As String = Console.ReadLine()

        FreeConsole()
    End Sub

Answer 1

Use of a console in a Windows Forms application seems to be finicky and seems to be unnecessary for that. When I changed getpassword to be:

AllocConsole()
Console.Write("Here I am! ")
Console.WriteLine("Hello World!")
Console.WriteLine("Enter Password:  ")
Dim name As String = String.Empty
Try
    name = Console.ReadLine()
Catch ex As Exception
    MsgBox("Can't write to console:" & vbCrLf & ex.Message)
End Try
FreeConsole()
MsgBox("You entered: " & name)

That works as expected. But why use a console? You can use an InputBox as in:

Dim name As String = InputBox("Enter a name")

Answer 2

Hi @Eugene Gough ,
If you do want to display 'Console.Write' in WinForm, then you can refer to the following steps.
Create a Module :

Imports System.Runtime.InteropServices  
  
Module Program  
    <DllImport("kernel32.dll")>  
    Private Function AttachConsole(ByVal dwProcessId As Integer) As Boolean  
    End Function  
    Private Const ATTACH_PARENT_PROCESS As Integer = -1  
    Sub main()  
        AttachConsole(ATTACH_PARENT_PROCESS)  
        Application.Run(New Form1())  
    End Sub  
End Module  

Then in 'Project Properties' > Application , set 'Startup object' to 'Sub Main' and 'Application type' to 'Console Application', finally un-check the 'Enable application framework' check box.

Code in button1:

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles   
    Button1.Click  
        Console.Write("Here I am! ")  
        Console.WriteLine("Hello World!")  
        Console.WriteLine("Enter Password:  ")  
        Dim name As String = Console.ReadLine()  
        TextBox1.Text = name  
    End Sub  

Result of my test:

Hope it could be helpful.

Best Regards,
Xingyu Zhao
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Answer 3

Thanks. I didn't know about InputBox. I had never had an occasion for the need to get a password prior to allowing a screen to fill. Thanks. Even at 87, I just keep on finding out that I don't know a lot of stuff. :-)
@Sam of Simple Samples