RadGridView very slow in virtual mode

[Louis]

Hi

I have been having a lot of trouble get RadGridView to work in virtual mode. If the RowCount is set to a large number it makes the scrolling very choppy and slow to respond. It can take up to 5 seconds for the grid to show the row data after the scroll bar is moved. I have created a test program to strip out all my code and it proves the problem is with the grid. There seems to be a lot of overhead somewhere. Don't know why the RowCount should affect performance if this is truly a virtual mode and I provide the data in CellValueNeeded then you should not be doing much. By the way, tried my code with DataGridView and it works really fast and can handle the row count being updated continuously and autoscrolling to bottom. I would expect the example program below to be incredibly fast - am I missing something?

namespace RadControlsWinFormsApp1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();


radGridView1.VirtualMode = true;
radGridView1.RowCount = 1000000;
radGridView1.ColumnCount=5;


}


private void radGridView1_CellValueNeeded( object sender, Telerik.WinControls.UI.GridViewCellValueEventArgs e )
{
e.Value = string.Format( "{0}:{1}", e.RowIndex, e.ColumnIndex );
}
}
}

[Julian Benkov]

Hello Louis,

Your question has already been answered in the support thread that you've opened regarding the same matter. Please, see our answer there for more information.

We kindly ask you to use just one support channel to contact us. Posting the same questions numerous times slows down our response time because we will need to review and address two or more tickets instead of one. Moreover threads are handled according to license and time of posting, so if it is an urgent problem, we suggest you use a support ticket, which would be handled before a forum thread.

Thank you for your understanding.

Greetings,
Julian Benkov
the Telerik team

[Dave]

A link to the "other" answer would have been helpful, as this is the one that came up in my search results and no answer is linked from here.

[Julian Benkov]

Hello Dave,

Thank you for writing.

The "other" thread is a support ticket which is private communication and this is the reason link is not posted. 

For your convenience, here is the answer to the question:

Currently, RadGridView does not support full virtual mode functionality. The implementation creates logical rows based on the RowCount property. This is the reason for the performance issues when the RowCount is set to a larger value. 

To support full virtualization stack along with sorting, filtering and virtual grouping operations we have to redesign the virtualization layer of RadGridView control. This is a complex task and it should be tested in more cases, including data loading, CRUD operations, usage of cached data. Currently, there are some requests for such features and if these requests continue to increase, we will do our best to put some resources in this direction in future. Still, because of the complex nature of the feature, I am not able to provide you with a specific time frame. 

I hope you find this information useful. Let me know if you need further assistance.

All the best,
Julian Benkov
the Telerik team