Timer countdown then launch program

[jmasgalas]

I posted this to a different forum but now I think it belongs here...

First Hi all! I am new here. I am also just beginning to program using vb.net and Visual Studio 2005. I am having trouble creating a program that uses a timer.

I want a timer to start when the form loads at 3 minutes and countdown to 0. The timer should display the time left in a text box. When it reaches zero I want it to stop, launch an external program, and close the form.

Can anyone help me with this? I know it is simple but I am just learning.

Thanks so much!

 

[JohnH]

Timer doesn't count down, it only triggers at the interval you set. Using the Date and TimeSpan data types you can calculate the time since start and subtract this from a 3 minutes timespan. The Process class can run the program.

First add the Timer from Toolbox Components to form, set its Interval to 1000 which is 1 second, its Enabled to True which mean it will be running from start. Here is all the code necessary:

Private starttime As Date
 
Private Sub frm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    starttime = Date.Now
End Sub
 
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
    Dim countdown As New TimeSpan(0, 3, 0)
    countdown = countdown.Subtract(Date.Now.Subtract(starttime))
    CountdownTextBox.Text = String.Format("{0}:{1:00}", countdown.Minutes, countdown.Seconds)
    If countdown.TotalSeconds <= 0 Then
        Timer1.Enabled = False
        Process.Start("calc.exe")
    End If
End Sub

 

[jmasgalas]

Thanks JohnH! I will try it when I get back to work on Monday. This is for a program I am trying to write at work for a group of users.

 

[jmasgalas]

Hey John H that worked great. Would you mind explaining it a bit to me. I am having a hard time understanding the countdown variable declaration, how it works, and the text box formatting.

Basically I just wanted you to break it down for me so I can understand it better.

Thanks!