check if mdi child is open

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  • Start date Start date
G

Guest

i have a Form1 that is opening Form2 by calling Form2.Show()

is there an easy way to check for a child? for Form1 to see if there is
already a Form2 on this thread. there can be 2 Form1s, so it needs to look
for the Form2 that it oppened.

Thanx in advance
 
oscar said:
i have a Form1 that is opening Form2 by calling Form2.Show()

is there an easy way to check for a child? for Form1 to see if there is
already a Form2 on this thread. there can be 2 Form1s, so it needs to
look
for the Form2 that it oppened.
Click to expand...

\\\
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>
 
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