Very weird problem using NotifyIcon and Context Menu for MSN like form/app closing behavior

[ThunderMusic]

Hi,

I'm trying to have a MSN Messenger like form/app closing behavior. When I
click on the X button, I only want the form to disappear and when I
double-click on the notify icon or right-click on it and choose Open from
the context menu, I want the form to reappear. For that, I got the point
covered. Even when the form is minimize, the behavior is like MSN Messenger.

But one problem arose. When I close the form (the first time), it disappears
(that is ok), but after that, when I open it again, it appears, then if I
try to close it (for the second time), it disappears then reappears
immediately, if I close it again (for a third time), then, it disappears...
In fact, except for the first time I close it, I have to close it twice...

I supplied the the code I use (maybe there's a more efficient way to code
it) at the end of this post. I hope that's all the code you need. I only
handle the Closing and Load events for the form, so I don't this this would
be a problem.

Thanks

ThunderMusic

Private Sub FRMMain_Closing(ByVal sender As Object, ByVal e As
System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
If Not m_ClosingApp Then
e.Cancel = True
Me.Visible = False
Me.ShowInTaskbar = False
End If
End Sub

Private Sub NIMS_DoubleClick(ByVal sender As Object, ByVal e As
System.EventArgs) Handles NIMS.DoubleClick
Me.Visible = True
Me.ShowInTaskbar = True

If Me.WindowState = FormWindowState.Minimized Then
Me.WindowState = FormWindowState.Normal
End If
End Sub

Private Sub MNUOpen_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MNUOpen.Click
Me.Visible = True
Me.ShowInTaskbar = True

If Me.WindowState = FormWindowState.Minimized Then
Me.WindowState = FormWindowState.Normal
End If
End Sub

Private Sub MNUExit_Click(ByVal sender As Object, ByVal e As
System.EventArgs) Handles MNUExit.Click
m_ClosingApp = True
Me.Close()
End Sub

private m_ClosingApp as boolean

 

[ThunderMusic]

I don't get it at all... I solved the problem and I know which instruction
produced the problem... but I don't know why it causes the problem, maybe
someone could explain it to me?

The instruction causing the problem is "me.ShowInTaskBar = True (or False,
does the same problem)" In fact, I just removed those instructions from my
code and now it works fine (the app doesn't even show in task bar when it is
not visible, so everything is alright). But I don't know why the
ShowInTaskBar property, when toggled, was doing something causing my
TreeView to raise an AfterSelect Event, which seems to get in the way of the
window closing process (in any way). I just don't get why this event is
raised, because when going step-by-step, the call stack shows this (I've cut
some details out for each line, but you have all the lines in the call
stack):

FRMMain.TVAll_AfterSelect(Object sender = {System.Windows.Forms.TreeView},

....)
[<Non-user Code>]
FRMMain.FRMMain_Closing(Object sender = {JMSFE.FRMMain}, ...)

So if I understand well, the toggling of this property runs some non-user
code, and this non-user code fires the AfterSelect on my TreeView. Does
somebody understand all this? Can somebody explain what is happening?

Thanks

ThunderMusic

 

[Armin Zingler]

Hi,

I'm trying to have a MSN Messenger like form/app closing behavior. When I
click on the X button, I only want the form to disappear and when I
double-click on the notify icon or right-click on it and choose Open from
the context menu, I want the form to reappear. For that, I got the point
covered. Even when the form is minimize, the behavior is like MSN
Messenger.

But one problem arose. When I close the form (the first time), it
disappears
(that is ok), but after that, when I open it again, it appears, then if I
try to close it (for the second time), it disappears then reappears
immediately, if I close it again (for a third time), then, it
disappears...
In fact, except for the first time I close it, I have to close it twice...

I supplied the the code I use (maybe there's a more efficient way to code
it) at the end of this post. I hope that's all the code you need. I only
handle the Closing and Load events for the form, so I don't this this
would
be a problem.

[/QUOTE]

First, I can reproduce the problem. I see your 2nd posting also but let me
first answer this one:
If you set a breakpoint @ the form.visiblechanged event, you'll see that the
ShowInTaskbar property procedure indeed shows the Form again. Here's the
callstack:

WindowsApplication.Form1.Form1_VisibleChanged(sender, e) Zeile 119 Basic
System.Windows.Forms.Control.OnVisibleChanged(e)
System.Windows.Forms.ScrollableControl.OnVisibleChanged(e)
System.Windows.Forms.Form.OnVisibleChanged(e)
System.Windows.Forms.Control.SetVisibleCore(value)
System.Windows.Forms.Form.SetVisibleCore(value)
System.Windows.Forms.Control.set_Visible(value)
System.Windows.Forms.Form.CreateHandle()
System.Windows.Forms.Control.RecreateHandleCore()
System.Windows.Forms.Form.RecreateHandleCore()
System.Windows.Forms.Control.RecreateHandle()
System.Windows.Forms.Form.set_ShowInTaskbar(value)
WindowsApplication.Form1.Form1_Closing(sender, e) Zeile 100 Basic


If you needed to set this property - you don't as you've already written - I
would have recommended to set it before the visible property. This does
work.


Armin

 

[Armin Zingler]

I don't get it at all... I solved the problem and I know which
instruction produced the problem... but I don't know why it causes
the problem, maybe someone could explain it to me?

The instruction causing the problem is "me.ShowInTaskBar = True (or
False, does the same problem)" In fact, I just removed those
instructions from my code and now it works fine (the app doesn't
even show in task bar when it is not visible, so everything is
alright). But I don't know why the
ShowInTaskBar property, when toggled, was doing something causing my
TreeView to raise an AfterSelect Event, which seems to get in the
way of the window closing process (in any way). I just don't get why
this event is raised, because when going step-by-step, the call
stack shows this (I've cut some details out for each line, but you
have all the lines in the call stack):

FRMMain.TVAll_AfterSelect(Object sender =
{System.Windows.Forms.TreeView},

...)
[<Non-user Code>]
FRMMain.FRMMain_Closing(Object sender = {JMSFE.FRMMain}, ...)

So if I understand well, the toggling of this property runs some
non-user code, and this non-user code fires the AfterSelect on my
TreeView. Does somebody understand all this? Can somebody explain
what is happening?

In the call stack window's context menu, enable "show non-user code" and
post the call stack again.


Armin