I have a annoying problem with repainting my devexpress XtraGrid.

I use this code to draw Icons into a cell:

        ' Check Validation
        Dim guidString As String = view.GetRowCellValue(e.RowHandle, NameOf(DataModel.Contract.GuidId)).ToString()
        Dim guidId As Guid

        If Guid.TryParse(guidString, guidId) Then
            Dim validationResult As New DataModel.ValidationResult()

            ' Check if result is in cache
            If Not _validationCache.TryGetValue(guidId, validationResult) Then
                Task.Run(Sub()
                             Using taskContext As New DbContext()
                                 Dim entry As DataModel.InstAuftrag = taskContext.InstAuftraege.Find(guidId)
                                 If entry IsNot Nothing Then
                                     validationResult = entry.Validate(taskContext, exitOnFirstError:=True)
                                 Else
                                     validationResult = New DataModel.ValidationResult
                                 End If

                                 ' Add result to cache
                                 _validationCache.TryAdd(guidId, validationResult)

                             End Using
                         End Sub)
            End If

            If validationResult.Icon IsNot Nothing Then
                iconKeys.Add(validationResult.Icon)
            End If

            If iconKeys.Count > 0 Then
                Dim iconSize As New Size(32, 32)
                IconHelper.DrawIcons(e, iconKeys, _imageCollection, iconSize)
            End If

            e.Handled = True

        End If

    End If
End Sub

As you can see I using a task to do a validation and with that validation result I get back the icon name which I then use to draw into the cell. This works without any issues but there is the problem, that the Icon is displayed only after moving over the cell with my mouse or clicking some buttons on the form. It is related to the repaint of the form but I don’t know how to handle it.

I tried to invalidate the entire view/row/cell like this:

            If Not _validationCache.TryGetValue(guidId, validationResult) Then
                Task.Run(Sub()
                             Using taskContext As New DbContext()
                                 Dim entry As DataModel.InstAuftrag = taskContext.InstAuftraege.Find(guidId)
                                 If entry IsNot Nothing Then
                                     validationResult = entry.Validate(taskContext, exitOnFirstError:=True)
                                 Else
                                     validationResult = New DataModel.ValidationResult
                                 End If

                                 ' Add result to cache
                                 _validationCache.TryAdd(guidId, validationResult)

                             End Using
                         End Sub)
                   view.invalidate
            End If

This works only for the initial load, but when I scroll down my list the GUI is locked for some time and it’s really annoying.

Is there any better way to accomplish this task?

Thank you!