how to avoid combo box reset when scrolling datagridcombo box

See more:

VB

WPF

I am bind datagrid using List in wpf and bind combobox in datagrid but i am scroll datagrid that time combox has been reset following my code any one can give me solution
Reasion :- Grid Scroll Time

Desizen :-

<DataGrid x:Name="grddisplay"   TabIndex="1"  AutoGenerateColumns="False" ItemsSource="{Binding C_HoldControlValue}"    FontSize="11" HorizontalAlignment="Left"  Margin="10,58,0,0" VerticalAlignment="Top" Width="414" Height="455" IsTabStop="True" RenderTransformOrigin="0.5,0.5" FontFamily="Verdana" >
            <DataGrid.Columns>
                <DataGridTextColumn Header="Item No" Width="60" Binding="{Binding SrNo}"></DataGridTextColumn>
               <DataGridTemplateColumn Header="Remark" Width="60">
                    <DataGridTemplateColumn.CellTemplate>
                        <DataTemplate>
                            <ComboBox Margin="2" Name="cmbbindremark"  SelectedIndex="1" SelectedItem="Control_Remark"   SelectedValue="{ Binding  Control_Remark, Mode=TwoWay }"   ItemsSource="{Binding C_Remarks_Collection,Mode=TwoWay}"/>
                        </DataTemplate>
                    </DataGridTemplateColumn.CellTemplate>
                </DataGridTemplateColumn>
                <!--<DataGridComboBoxColumn  Header="Remarks"  x:Name="cmbbindremark" ItemsSource="{Binding C_Remarks_Coll}"  SelectedItemBinding ="{ Binding  C_Remarks_Collection,Mode=TwoWay}"   Width="110" ></DataGridComboBoxColumn>-->
            <DataGridTextColumn Header="Remarks" Width="80" Binding="{Binding Remarks}"></DataGridTextColumn>
            <DataGridTextColumn Header="Category" Width="90" Binding="{Binding Category}"></DataGridTextColumn>
                <DataGridTextColumn Header="Caption" Width="160" Binding="{Binding  Caption}" ></DataGridTextColumn>
            </DataGrid.Columns>
        </DataGrid>

Code:-

Dim C_HoldControlValue As New List(Of ControlValue)()
       Try
           grddisplay.AutoGenerateColumns = True
           svbutton.IsEnabled = False
           Dim OCcmd As New SqlCommand
           Dim OCadp As New SqlDataAdapter
           Dim strin() As String = Nothing
           OCcmd = New SqlCommand("select cbsrno,Remarks,Category,cbcaptons,trgvalue from ControlBox order by cbsrno", sqlcn)
           OCadp.SelectCommand = OCcmd
           OCadp.Fill(ds_cntrl, tblname)
           dv2 = New DataView(ds_cntrl.Tables(tblname))
           Dim splStrRemark As DataRow = ds_cntrl.Tables(0).Rows(1)

         

           grddisplay.ItemsSource = LoadCollectionData(ds_cntrl)
           grddisplay.AutoGenerateColumns = False


          
       Catch
       End Try

   End Sub

function :-

Public Function LoadCollectionData(ByVal ds As DataSet) As List(Of ControlValue)

       Dim strin() As String = Nothing
       Dim authors As New List(Of ControlValue)()
       For Each dr As DataRow In ds.Tables(0).Rows
           Dim s As String = dr("Remarks")
           If dr.Table.Columns(1).ToString = "Remarks" Then
               Dim dsa As String = s.ToString
               strin = dsa.ToString.Split(",")
           End If
           authors.Add(New ControlValue() _
                With { _
               .SrNo = dr(0), _
               .Remarks = dr(4), _
               .Category = dr(2), _
               .Caption = dr(3), _
               .C_Remarks_Collection = strin})
       Next
       grddisplay.CanUserAddRows = False
       Return authors
   End Function

property :-
Public Class ControlValue
Private C_Remarks As String
Private C_Caption As String
Private C_Category As String
Private C_SrNo As String
Private C_RemarksColl() As String
Public Property Remarks() As String
Get
Return C_Remarks
End Get
Set(value As String)
C_Remarks = value
End Set
End Property

Public Property Caption() As String
Get
Return C_Caption
End Get
Set(value As String)
C_Caption = value
End Set
End Property

Public Property Category() As String
Get
Return C_Category
End Get
Set(value As String)
C_Category = value
End Set
End Property

Public Property SrNo() As String
Get
Return C_SrNo
End Get
Set(value As String)
C_SrNo = value
End Set
End Property
Public Property C_Remarks_Collection() As String()
Get
Return C_RemarksColl
End Get
Set(value As String())
C_RemarksColl = value
End Set
End Property
End Class