Many programs display message boxes that automatically close after a period of time, including printer errors and closing outlook. In VB, this is more complicated than it should be, but still possible. Here's how.
'Module Code
Private Declare Function KillTimer Lib "user32" (ByVal hWnd
As Long, ByVal nIDEvent As Long) As Long
Private Declare Function FindWindow Lib "user32" Alias "FindWindowA"
(ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Private Declare Function SetForegroundWindow Lib "user32" (ByVal hWnd
As Long) As Long
'// Message we receive telling us to close the message box
Public Const NV_CLOSEMSGBOX As Long = &H5000&
Public Sub TimerProc(ByVal hWnd As Long, ByVal uMsg As Long, ByVal idEvent As
Long, ByVal dwTime As Long)
'// this is a callback function. This means that windows
"calls back" to this function
'// when it's time for the timer event to fire
'// first thing we do is kill the timer so that no other
timer events will fire
KillTimer hWnd, idEvent
'// select the type of manipulation that we want to perform
Select Case idEvent
Case NV_CLOSEMSGBOX '// we want to close this messagebox
after 4 seconds
Dim hMessageBox As Long
'// find the messagebox window
'// change the text to whatever the
title of the message box is
hMessageBox = FindWindow("#32770",
"Self Closing Message Box")
'// if we found it make sure it has
the keyboard focus and then send it an enter to dismiss it
If hMessageBox Then
Call SetForegroundWindow(hMessageBox)
'// this
will result in the default option being chosen
SendKeys
"{enter}"
End If
End Select
End Sub
'Form Code
Private Declare Function SetTimer Lib "user32" (ByVal hWnd
As Long, ByVal nIDEvent As Long, ByVal uElapse As Long, ByVal lpTimerFunc As
Long) As Long
Private Sub cmdShowMsg_Click()
'// this shows a messagebox that will be dismissed after
4 seconds
'// set the callback timer and pass our application defined
ID (NV_CLOSEMSGBOX)
'// set the time for 4 seconds (4000 microseconds)
SetTimer hWnd, NV_CLOSEMSGBOX, 4000, AddressOf TimerProc
'// call the messagebox function
If MsgBox("Watch this message box close itself after
four seconds. The printer is out of paper. Retry or Cancel? (Example)",
vbRetryCancel + vbDefaultButton1, "Self Closing Message Box") = vbRetry
Then
MsgBox "Retry!"
Else
MsgBox "Cancel"
End If
End Sub
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