How to restrict the multiple opening of the Same window...

[Prabhudhas Peter]

If I click a menu to open a form which already open...the vb.net opens a new
window while existing open window is there...i want to restric the opening of
a new instance of an already opened form...
and also ...
if i open a form from a child form of an MDI form, the recently opened form
also should be the child of that MDI form...
--
Peter...

[Herfried K. Wagner [MVP]]

"Prabhudhas Peter" <Pr*************@discussions.microsoft.com> schrieb:

If I click a menu to open a form which already open...the vb.net opens a
new
window while existing open window is there...i want to restric the opening
of
a new instance of an already opened form...
and also ...
\\\
Private m_Child As Form2

Private Sub Button1_Click( _
ByVal sender As Object, _
ByVal e As EventArgs _
) Handles Button1.Click
If m_Child Is Nothing Then
m_Child = New Form2()
m_Child .MdiParent = Me
AddHandler m_Child.Load, AddressOf Me.MdiChild_Load
AddHandler m_Child.Closed, AddressOf Me.MdiChild_Closed
End If
m_Child.Show() ' ...
End Sub

Private Sub MdiChild_Load( _
ByVal sender As Object, _
ByVal e As EventArgs _
)
MsgBox( _
"MDI child with handle " & _
DirectCast(sender, Form).Handle.ToString() & _
" loaded!" _
)
End Sub

Private Sub MdiChild_Closed( _
ByVal sender As Object, _
ByVal e As EventArgs _
)
MsgBox( _
"MDI child with handle " & _
DirectCast(sender, Form).Handle.ToString() & _
" closed!" _
)
m_Child = Nothing
End Sub
///

Alternatively you can implement the Singleton design pattern in your MDI
child form:

Implementing the Singleton Pattern in C#
<URL:http://www.yoda.arachsys.com/csharp/singleton.html>

Exploring the Singleton Design Pattern
<URL:http://msdn.microsoft.com/library/en-us/dnbda/html/singletondespatt.asp>

Design Pattern: Singleton in C#
<URL:http://www.devhood.com/tutorials/tutorial_details.aspx?tutorial_id=486>

Design Patterns: Singleton
<URL:http://www.dofactory.com/Patterns/PatternSingleton.aspx>
if i open a form from a child form of an MDI form, the recently opened
form
also should be the child of that MDI form...

\\\
Dim f As New FooForm()
f.MdiParent = Me.MdiParent
f.Show()
///

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

[Woo]

ur coding works great. but what if i hv different forms for different usage?
i need to repeat the load and close to indicate those forms = nothing? maybe
you could advise on that. thanks a lot.

"Herfried K. Wagner [MVP]" wrote:

"Prabhudhas Peter" <Pr*************@discussions.microsoft.com> schrieb:

If I click a menu to open a form which already open...the vb.net opens a
new
window while existing open window is there...i want to restric the opening
of
a new instance of an already opened form...
and also ...

\\\
Private m_Child As Form2

Private Sub Button1_Click( _
ByVal sender As Object, _
ByVal e As EventArgs _
) Handles Button1.Click
If m_Child Is Nothing Then
m_Child = New Form2()
m_Child .MdiParent = Me
AddHandler m_Child.Load, AddressOf Me.MdiChild_Load
AddHandler m_Child.Closed, AddressOf Me.MdiChild_Closed
End If
m_Child.Show() ' ...
End Sub

Private Sub MdiChild_Load( _
ByVal sender As Object, _
ByVal e As EventArgs _
)
MsgBox( _
"MDI child with handle " & _
DirectCast(sender, Form).Handle.ToString() & _
" loaded!" _
)
End Sub

Private Sub MdiChild_Closed( _
ByVal sender As Object, _
ByVal e As EventArgs _
)
MsgBox( _
"MDI child with handle " & _
DirectCast(sender, Form).Handle.ToString() & _
" closed!" _
)
m_Child = Nothing
End Sub
///

Alternatively you can implement the Singleton design pattern in your MDI
child form:

Implementing the Singleton Pattern in C#
<URL:http://www.yoda.arachsys.com/csharp/singleton.html>

Exploring the Singleton Design Pattern
<URL:http://msdn.microsoft.com/library/en-us/dnbda/html/singletondespatt.asp>

Design Pattern: Singleton in C#
<URL:http://www.devhood.com/tutorials/tutorial_details.aspx?tutorial_id=486>

Design Patterns: Singleton
<URL:http://www.dofactory.com/Patterns/PatternSingleton.aspx>

if i open a form from a child form of an MDI form, the recently opened
form
also should be the child of that MDI form...

\\\
Dim f As New FooForm()
f.MdiParent = Me.MdiParent
f.Show()
///

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>