VB2005 maintain focus on hidden app

[jontcaz]

Good Day,
I have an application that will send text out of a serial port if i hold down the "1" key for 2 seconds. I am currently just turning a chime on and off but want to expand this to the ability to turn my amplifier on/off etc. I want this to be running in the background but to respond at any time by just hitting a certain key. The program works great one time when i execute, but goes into hide and i never see it again. Any suggestions are appreciated.

Public Class frmKeyCatcher
Dim WithEvents serialPort As New IO.Ports.Serial Port

Private Sub DataReceived( _
ByVal sender As Object, _
ByVal e As System.IO.Ports .SerialDataRece ivedEventArgs) _
Handles serialPort.Data Received

txtDataReceived .Invoke(New myDelegate(Addr essOf updateTextBox), _
New Object() {})
End Sub

Public Delegate Sub myDelegate()
Public Sub updateTextBox()
With txtDataReceived
.SelectionColor = Color.Red
.AppendText(ser ialPort.ReadExi sting)
.ScrollToCaret( )
End With
End Sub

Private Sub frmKeyCatcher_F ormClosing(ByVa l sender As Object, ByVal e As System.Windows. Forms.FormClosi ngEventArgs) Handles Me.FormClosing
serialPort.Clos e()
End Sub


Private Sub frmKeyCatcher_K eyDown(ByVal sender As Object, ByVal e As System.Windows. Forms.KeyEventA rgs) Handles Me.KeyDown
If e.KeyCode = 49 Then
Timer1.Start()

End If
End Sub

Private Sub frmKeyCatcher_K eyUp(ByVal sender As Object, ByVal e As System.Windows. Forms.KeyEventA rgs) Handles Me.KeyUp
If e.KeyCode = 49 Then
Timer1.Stop()
End If
End Sub

Private Sub Timer1_Tick(ByV al sender As Object, ByVal e As System.EventArg s) Handles Timer1.Tick
Me.Show()
Me.BackColor = Color.LightGray
If serialPort.IsOp en Then
serialPort.Clos e()
End If
Try
With serialPort
.PortName = "COM3"
.BaudRate = 96000
.Parity = IO.Ports.Parity .None
.DataBits = 8
.StopBits = IO.Ports.StopBi ts.One

End With

serialPort.Open ()
Timer4.Start()
Catch ex As Exception
MsgBox(ex.ToStr ing)
End Try

End Sub

Private Sub Timer2_Tick(ByV al sender As Object, ByVal e As System.EventArg s) Handles Timer2.Tick
Me.Hide()
Timer2.Stop()
End Sub

Private Sub Timer4_Tick(ByV al sender As Object, ByVal e As System.EventArg s) Handles Timer4.Tick
Try
serialPort.Writ e("C")
With txtDataReceived
.SelectionColor = Color.Black
.AppendText("C" & vbCrLf)
.ScrollToCaret( )

End With
Me.BackColor = Color.white
Catch ex As Exception

End Try
Timer4.Stop()
Timer2.Start()
End Sub


End Class

[Robbie]

... I want this to be running in the background but to respond at any time by just hitting a certain key. ...

Hi. The code which you posted does not look like VB6 code...

I have a 'Declare Function' which you can use in VB6. I don't know if you can use it in .NET though, because I'm not really advanced with it.

[code=vb]Private Declare Function GetAsyncKeyStat e Lib "user32" (ByVal vKey As Long) As Integer[/code]

You use it by giving it a keycode to check for. It seems to check the keyboard directly, rather than the program having to have focus for it to work. If it gives back -32767, then the key is pressed, otherwise it's not.

So it would be easier to set up a constant of that, e.g.
[code=vb]Const KeyPressed As Integer = -32767[/code]

Then check the function against that constant, e.g. to check if the Space key is being pressed:

if GetAsyncKeyStat e(vbKeySpace) = KeyPressed then
'The key is down
else
'It's not being pressed down
end if

As I said, that's VB6 code, but I hope you can apply it to what you need it for. And I haven't tested, but there is equivalent code in another programming language I'm familiar with, to check the keyboard directly (and I assume this is what this function does), and it works without the program having to have focus.

EDIT: So you'd need to check regularly with a timer or while-doevents-wend loop or such, whether or not the key is currently down.

[jontcaz]

[QUOTE=Robbie]Hi. The code which you posted does not look like VB6 code...

Hey Robbie, thanks for the reply, i guess i should have posted this in .net forum eh? I will try your ideas in 6 to see if that works.