RadGridView - Data Virtualization

[Godwin]

Hi,

I have a requirement to populate high volume of data(>50000 rows) in the gridview. I feel data vitualization/lazy loading is a good way to implement this. If I load 500 records at a time and keep loading while scrolling the content the next set, how can I address the following scenarios :

• Select All option(for the whole underlying datasource)
• Sorting, grouping features of the grid(for the whole underlying datasource)
• Export to excel feature(for the whole underlying datasource)

Assuming all the records are not loaded for the above mentioned scenarios,

Regards,
Anand

[Vlad]

Hi Anand,

 Generally you can sort and/or filter all data even with our virtual collection. Please check our demos and documentation! As for the select all and export all I'm afraid that this will need all the data and will defeat the purpose of virtualization. You can use Telerik Reporting to export all the data independently of the virtual collection. 

Kind regards,
Vlad
the Telerik team

[Timothy]

Can you point me to any examples of filtering and sorting RadGridView with Data Virtualization in place?  Specifically something that shows the event handling in the filtering situation whereby I can go back to the server and get the complete list of distinct values for a column to be shown in the filter dialog and then, of course, the event handling needed to repopulate the ItemSource with the filtered results.
I'm assuming that Sorting will be similar only without the need to fetch any values (just changing the current sort order on the column).

Thanks.

Tim

[Vlad]

Hi,

 Have you checked our demos for Data Virtualization? Is there anything you don't understand? You can check also our documentation for more info on how to load distinct values.

Greetings,
Vlad
the Telerik team

[Rahul]

Hii,

My requirement is also similar. I want to load the gridView data in small chunks at regular intervals of time (async). But by the time the user clicks on the Filter dialog on a column, since all the data in my grid is not yet loaded, I will now make the service call in DistinctValues Loading event (Async call), and in the call back of that call, I will populate the entire Distinct list of values (which may or may not be there in the grid in that column) into the filter dialog list box.

But my problem is that, I gone through the entire filtering documentation and did-not see how to populate the values into the Filter Dialog when you are not in the DistinctValuesLoading Event. from my call back method I need to populate the values. Can you please let me know how do I do it.


I tried to do it with ColumnFilterDescriptor, but later realized that it is to add filter on the column
 
I am little stuck and more over the above link you specified is not working.... its say "An error occurred while processing your request."


Can you please provide me with a sample demo how to populate the data into the fitler dialog in my own method and not from the DistinctValuesLoading event.


Thank you in advance!!

Its little urgent pls :)

[Dimitrina]

Hi,

The recommended approach when using Data Virtualization (VirtualQueryableCollectionView) and filtering is to work with the FieldFilters only (and not with DistictFilters). 

In order to configure the column that way, you need to set ShowDistinctFilters="False" for it.
For example:

<telerik:GridViewDataColumn DataMemberBinding="{Binding OrderID}" Header="OrderID" ShowDistinctFilters="False"/>

 
I hope this helps.

Regards,
Didie
Telerik

 

 

[Valentina]

Hi Vlad, 

Data Virtualization support in RagGridView looks very promising and I'd like to try it for my projects.  Though, all the examples I could find use querying a data base as a data source.  I'd need to do the same but reading data from a huge text file with lines of different length.  Could you please point me in the right direction or give me a link with such example?

Thanks,

Valentina

[Dilyan Traykov]

Hello Valentina,

What I can suggest is for you to have a look at the following example which demonstrates how to use the ItemsLoading event. Please note that you will need to use Internet Explorer to open it.

Inside of the ItemsLoading event handler you can use the VirtualQueryableCollectionView's Load method and use the StartIndex and ItemCount properties of the VirtualQueryableCollectionViewItemsLoadingEventArgs to load the necessary lines from your text file.

I hope you find this helpful. If you require any further assistance on the matter, please let me know.

Regards,
Dilyan Traykov
Progress Telerik

[Valentina]

Hi Dilyan,

Thanks for the link.  Though, the code doesn't build when I try it in a new desktop solution.  Is it for a web server?

I'm using your UI for WPF Q2 2016 and don't want to upgrade at this time because of existing customers support.

Could you please send me a complete working desktop app solution or, at least, tell me how to reference the following:

using Examples.Web;
using System.ServiceModel.DomainServices.Client;
using Telerik.Windows.Controls.DomainServices;

[Dilyan Traykov]

Hello Valentina,

The project I referenced is built for the Silverlight framework and uses RIA services, so it cannot be converted to a WPF project. I pointed you to this example to give you an idea of how the ItemsLoading event can be used.

Please note, however, that reading the contents of a file will not be as straightforward as you will need to work with the actual file stream and keep track of the position in the stream. I'm afraid I cannot provide you with a working example as the implementation of such custom functionality goes out of the scope of the support services we provide.

If I can, however, assist you in any other way, please let me know.

Regards,
Dilyan Traykov
Progress Telerik