KababChi KababChi - 2 months ago 28x
Vb.net Question

Error after disposing form in MDI Parent

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
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.
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.
Protected Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing AndAlso components IsNot Nothing Then
End If
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 ?


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