Error after disposing form in MDI Parent

Question

i have a MDI Parent as the parent form and i use it to open and organize other forms as child inside it. i use this method to open child forms :

Public Sub OpenForm(ByVal frm As Form)
    frm.MdiParent = MainView
    frm.Show()
End Sub

the method works correctly and i don't have any problem using it to open child forms. i have 3 items in each child form :

1- DataGridViewX (from DevComponents.DotNetBar.Controls)

2- Panel

3- UserControl

i can use each of these items correctly and no error shows up. DataGridViewX is connected with a DataSource and everything is correct. the problem occurs when i open 2 or more forms inside the MDI Parent and then try to close them. the Error is :

    The following exception occurred in the DataGridView:
System.IndexOutOfRangeException: Index 0 does not have a value.
at
System.Windows.Forms.CurrencyManager.get_Item(Int32index) 
at
System.Windows.Forms.DataGridView.DataGridViewDataConnection.G" and caption "DataGridView Default Error Dialog".

and this is the code responsible for error :

Partial Class Form1
    Inherits DevComponents.DotNetBar.OfficeForm

    'Form overrides dispose to clean up the component list.
    <System.Diagnostics.DebuggerNonUserCode()>
    Protected Overrides Sub Dispose(ByVal disposing As Boolean)
        Try
            If disposing AndAlso components IsNot Nothing Then
                components.Dispose()
            End If
        Finally
            MyBase.Dispose(disposing) '' <<<< ERROR LINE
        End Try
    End Sub

now obviously i don't code inside designer nor put elements inside form using the code. i use the Designer interface.

what should i do ? thanks

Answer 1

just set binding source of DataGridViewX to nothing and problem solved !

Private Sub theForm_FormClosing(sender As Object, e As FormClosingEventArgs) Handles Me.FormClosing
    DataGridViewX1.DataSource = Nothing
End Sub