Vb. NET implementation shutdown and reboot

Private Declare Function exitwindowsex Lib "user32" (ByVal uflags As Integer, ByVal dwreserved As Integer) As Integer

Const Ewx_force as Short = 4

Const Ewx_logoff as Short = 0

Const Ewx_reboot as Short = 2

Const Ewx_shutdown as Short = 1

Dim RetVal as Integer

' Define ESC key

Const Vk_escape as Short = &h1bs

Private Sub Command1_Click (ByVal Eventsender as System.Object, ByVal EventArgs as System.EventArgs) Handles Command1.click

If option1.checked Then

' Log off the current user

retval = ExitWindowsEx (ewx_force, 0)

ElseIf option2.checked Then

"Shut down the computer

retval = ExitWindowsEx (ewx_shutdown, 0)

ElseIf option3.checked Then

"Reboot

retval = ExitWindowsEx (ewx_reboot, 0)

End If

End Sub

Private Sub Command2_Click (ByVal Eventsender as System.Object, ByVal EventArgs as System.EventArgs) Handles Command2.click

Me.close ()

End Sub

"When the ESC key is pressed, end the application

Private Sub form1_keypress (ByVal Eventsender as System.Object, ByVal EventArgs as System.Windows.Forms.KeyPressEventArgs) Handles mybase.keypress

Dim KeyAscii as Short = ASC (Eventargs.keychar)

If KeyAscii = Vk_escape Then

Me.close ()

End If

If keyascii = 0 Then

eventargs.handled = True

End If

End Sub

This example uses the Exitwindowex () API function to achieve shutdown and restart purposes. In the Exitwindowex () function, the parameter uflags specifies what action to take. The value of the parameter uflags and its description are listed in table 86-2.

Table 86-2 value and description of parameter uflags

Constant name

Value

Description

Ewx_force

4

Terminates all processes, including processes that are not responding, and logs off Windows

Ewx_reboot

2

Reboot the system

Ewx_shutdown

1

Shutting down the system

Ewx_logoff

0

Terminates all running processes and logs off Windows