one instance of form

in vb.net we can show the child form as:

dim frm as new childform1
frm.show

but if we call these line more than one then it will creates a another instance on childform....

how can we stop user to create more than 1 instance of a form...meanz only one form will exist

anand

Something like this should work for you .

VB Code:

Dim frm As Form
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
 
        If frm Is Nothing Then
            frm = New Form
            frm.Show()
        Else
            Exit Sub
        End If
 
    End Sub

or this:

VB Code:

Dim blnFound As Boolean = False
                Dim frmChild As Form
                For Each frmChild In Me.MdiChildren
                    If TypeOf frmChild Is frmSuperApproval Then
                        frmChild.Focus()
                        blnFound = True
                        Exit For
                    End If
                Next
                'If form not already loaded then load form 
                If blnFound = False Then
                    Dim frmSuperApproval1 As New frmSuperApproval()
                    frmSuperApproval1.MdiParent = Me
                    frmSuperApproval1.Show()
                End If

Your code is more efficient than mine . Cool :) .