Question

I am using a datagridview to show my own items in it as List(Of MyStuff) and it works quiete well. When my class is changing the content the DataGrid does not change. I need to do DataGrid1.Items.Refresh and the items becomes updates.

But now my list contains 700 items and the .Refresh methode takes about 15 seconds just because one item changed. I’ve searched for any “UpdateContent” or “RowUpdate” or “RefreshRow” but found nothing. How is the right way to update single Rows?

Private LCommand As New List(Of MyLogEntry)

Me.dgv.DataContext = Me.LCommand
        Me._LastUpdate = DateTime.MinValue
        Me._CurrentIndex = -1
        Call UpdateDgv()



Private Sub UpdateDgv()
    Application.Current.Dispatcher.Invoke(AsyncRefresh)
End Sub

    Private Sub RefreshDgvAsync()
    Try
        Me.dgv.SelectedIndex = Me._CurrentIndex
        Me.dgv.ScrollIntoView(Me.dgv.SelectedItem)
    Catch ex As Exception

    End Try

    If DateTime.Now.Subtract(Me._LastUpdate).TotalSeconds > 60 Then Me.dgv.Items.Refresh()
    Me._LastUpdate = DateTime.Now
End Sub

<DataGrid x:Name="dgv" Grid.Row="1" RowHeight="20" AutoGenerateColumns="False" Grid.Column="1" ItemsSource="{Binding}" CanUserAddRows="False" VerticalScrollBarVisibility="Auto"  ClipToBounds="True" GridLinesVisibility="Horizontal">
            <DataGrid.Columns>
                <DataGridTextColumn         Header="N°"         Binding="{Binding Index}"           Width="SizeToCells"     MinWidth="30" IsReadOnly="True" />
                <!--<DataGridCheckBoxColumn     Header="OK"         Binding="{Binding Successfully}"    Width="SizeToCells"     MinWidth="35" IsReadOnly="True"     Visibility="Collapsed"  />-->

                <DataGridTemplateColumn Header="State" IsReadOnly="True">
                    <DataGridTemplateColumn.CellTemplate>
                        <DataTemplate>
                            <Image x:Name="imgState" Source="{Binding StateImageUrl}" />
                        </DataTemplate>
                    </DataGridTemplateColumn.CellTemplate>
                </DataGridTemplateColumn>





                <DataGridTextColumn         Header="Logentry"      Binding="{Binding Title}"           Width="SizeToHeader"    MinWidth="80" IsReadOnly="True"  FontWeight="Bold"                    />
                <DataGridTextColumn         Header="Action" Binding="{Binding Description}"    Width="SizeToCells"     MinWidth="80" IsReadOnly="True"  FontSize="12"       />
                <DataGridCheckBoxColumn     Header="Available"  Binding="{Binding Necessary}"       Width="Auto"            MinWidth="35" IsReadOnly="True"                    />
                <DataGridTextColumn         Header="Log"        Binding="{Binding Log}"             Width="*"               MinWidth="50" IsReadOnly="False"  FontSize="8" Foreground="Gray"                />
            </DataGrid.Columns>
        </DataGrid>

Answer 1

It is not very clear for me why do you need to refresh your items at all. If you need to observe log entries collection changes then use ObservableCollection<LogEntry>, if you need to update cells when something in LogEntry changes then make it observable by implementing INotifyPropertyChanged.
When you call Refresh on underlying CollectionView all item containers are regenerated. And it takes a lot of time espacially when virtuallization is disabled.