coder000 » system

Shutdown, Restart or Log off Windows in VB.Net

Rahul Vyas — Wed, 02 Sep 2009 04:05:12 +0000

To shutdown computer through VB.NET, we use the API – ExitWindowsEx. However, there is one issue with this – we cannot shut the computer down if our application does not have the appropriate privileges (permissions). Here is the solution – a class encapsulating the ExitWindowsEx and other APIs needed for getting appropriate privileges.

Launch applications, links and mails from vb net

Rahul Vyas — Wed, 02 Sep 2009 03:22:15 +0000

This discussion uses System.Diagnostics.Process.Start method for functionality like providing a click-able web link, launching an email client (like outlook, mailto links), or launching another application from vb.net code.

What is common in all the three scenarios above?

In all of the cases we are trying to start another process from the current process (our application). This can be done by the Process class provided by .NET framework. To start the process we use the Start method.

Starting another application

To start an application from our code, we can use the Start method. Following piece of code starts calculator:

System.Diagnostics.Process.Start("calc.exe")

If you want to pass any arguments [...]

Minimize all windows through keybd_event in VB Net

Rahul Vyas — Tue, 01 Sep 2009 21:13:19 +0000

This code shows how can we minimize all open windows using keybd_event API.

The following statement declares the API:

Public Declare Sub keybd_event Lib &quot;user32.dll&quot; (ByVal bVk As Byte, ByVal bScan As Byte, ByVal dwFlags As Int32, ByVal dwExtraInfo As Int32)

After declaring the API as show in the above code, you may go ahead and use the API as in the following example. I have created a method to Minimize All windows.

Public Sub MinimizeAll() keybd_event(&amp;H5B, 0, 0, 0) keybd_event(&amp;H4D, 0, 0, 0) keybd_event(&amp;H5B, 0, &amp;H2, 0) End Sub

Monitor and respond to all Windows keyboard events in VB Net

Rahul Vyas — Tue, 01 Sep 2009 20:54:34 +0000

How do keyloggers work. How to read what key is pressed irrespective of focus on form or visibility of form and write code for handling it. Object Oriented wrapper for Windows Hook (with event) to address the above issues.