datagridview control continues update, gui flickers when scrolling window

Question

Problem: I have a Winform application with a form en on this form i have a databound DataGridView. The datagridview is updated from the backend by updating the bind object continuesly using a timer to get the data every 10 seconds. In order to update the gui with this new data i call a RefreshDatabindings. (if i do not do this, the gui is nog updated, i am binding to a BindingList and the object implement the INotifyPropertyChanged)

When the form is big enough to show the whole datagridview at once everything is working wel. But when the form is not big enough to show the hole datagridview a scrollbar appears.

When i scroll to the right to see the rest of the datagridview i see the gui flickering (only the part that wasn't visible before scrolling). When i strech the form to make de gridview fitting again, everything is working wel (no flashing and flickering). the flickering only happens when i have to scroll.

I am lost, can please somebody help me :)?

• I allready tryed the DoubleBuffered = true.

Thanks in advance!

BindingList<InstanceTableViewModel> viewModelList;

    public Form1()
    {
        InitializeComponent();

        DoubleBuffered = true;

        functionParamList = new List<FunctionParameter>();
        functionParamList.Add(new FunctionParameter { DeviceValue = 100, InstanceId = "1", Name = "A" });
        functionParamList.Add(new FunctionParameter { DeviceValue = 200, InstanceId = "2", Name = "B" });
        functionParamList.Add(new FunctionParameter { DeviceValue = 300, InstanceId = "3", Name = "C" });

        viewModelList = CreateInstanceTableViewModelList();

        dataGridView1.DataSource = viewModelList;

        //Create timer
        updateDataTimer = new System.Timers.Timer();
        updateDataTimer.Interval = 500;
        updateDataTimer.Elapsed += updateDataTimer_Elapsed;

        updateDataTimer.Start();
    }

    private void updateDataTimer_Elapsed(object sender, ElapsedEventArgs e)
    {
        ThreadPool.QueueUserWorkItem(ReadDataThreadPoolMethod);
    }

    private void ReadDataThreadPoolMethod(object state)
    {
        Random random = new Random();
        int randomNumber = random.Next(0, 100);


        foreach (FunctionParameter param in functionParamList)
        {
            param.DeviceValue = Convert.ToInt64(randomNumber);
        }
    }

    void functionParameter_PropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        var functionParameter = sender as FunctionParameter;
        var propertyName = e.PropertyName;
        var propertyValue = functionParameter.DeviceValue;
        var parameterName = functionParameter.Name;

        UpdateViewModel(functionParameter.InstanceId, propertyName, propertyValue, parameterName);

    }

    private void UpdateViewModel(string instanceId, string propertyName, long propertyValue, string parameterName)
    {
        var instanceViewModel = viewModelList.Single(x => x.InstanceId == instanceId && x.NameLabel == parameterName);

        if (instanceViewModel != null)
        {
            instanceViewModel.ValueHex = Convert.ToUInt16(propertyValue);
        }

        ResetBindingsSource();
    }

    delegate void UpdateBindingsInvoker();
    public void ResetBindingsSource()
    {
        if (!this.IsDisposed)
        {
            if (this.InvokeRequired)
            {
                this.Invoke(new UpdateBindingsInvoker(UpdateDataGrid));
            }
            else
            {
                UpdateDataGrid();
            }
        }
    }

    private void UpdateDataGrid()
    {            
        dataGridView1.Refresh();
    }

Answer 1

So here my solution:

You only uses the Forms DoubleBuffering, but the following code is an extension method to the DataGridview and successfully works (at my tests ;)

public static void DoubleBuffered(this DataGridView dgv, bool setting) 
    { 
        Type dgvType = dgv.GetType(); 
        PropertyInfo pi = dgvType.GetProperty("DoubleBuffered", 
              BindingFlags.Instance | BindingFlags.NonPublic); 
        pi.SetValue(dgv, setting, null); 
    }

I found this code right here at Codeprojct.

You can use it in this way:

YourDataGridView.DoubleBuffered(true);

I hope i could help you ^^