How to make a command occur only once

[scuffer]

Hey,
I have a command which has to occur when an object becomes visible. However the command must occur only once, and no more times. so i cant put it in a timer section. Where should i put it, or how can i make the command happen when the object become visible, and then ignore the fact that the object is still visible?

[Jacob Roman]

This should do it:

Dim Command_Once As Boolean
 
Public Sub Game_Loop()
 
     Do
 
          DoEvents
 
          'This is your part when you want an object to do
          'something once
 
          If Command_Once = False And Object_Whatever.Visible = True then
 
               Command_Once = True
 
               'Do whatever that command is
 
          End If
 
         'Draw stuff here
 
     Loop
 
End Sub

[noi_max]

This is almost along the lines of pseudo-code.. but perhaps it will help. The idea is to use a boolean that keeps it's value between calls. This could be a Global, or a local static.

Private Sub Form_Load()
 
   'Start with an invisible control
   myControl.Visible = False
   
End Sub
 
Private Sub Command1_Click()
 
   'In one event, make the control visible.
   myControl.Visible = True
   
End Sub
 
Private Sub Command2_Click()
 
   'In another event, check for visibility.
   'Use a static boolean to ensure the code after the check
   'runs only once.
   Static Switch As Boolean
   
   If myControl.Visible = True And Switch = False Then
      MsgBox "Control is visible"
      Switch = True
   End If
   
End Sub