Hi Parag,

I put together a small sample that binds the XamDataGrid to some data.  I then grouped by one of the columns and ran a timer which periodically updates the data in that column.  Using the latest build for 14.2, I do not see the grouping header becoming an empty string.  I have attached my sample so you can take a look.

What is the version number for the Infragistics assemblies that you are using?  Maybe you are using an older build?

Hi Parag,

If I allow null values then I do see a grouping get added which has an empty string but this is expected.  All the other groupings remain intact.  From the way you described your issue, though, it appears that all of your groupings are lost and only 1 group is left (the empty string group) with every single record being placed under this group.  I don't see this behavior using 14.1.20141.2062.  My sample is attached.

It is expected though that if you group by ColumnA for example, and a value in one of the records for ColumnA is changed to null, that record will be moved to a NULL group.  Since the value of the group is null, it displays an empty string.

I would like to point out that the current version of 14.1 is 14.1.20141.2216 so you are currently behind by a few versions.  I recommend updating to the latest version when you find that you are running into issues with the controls to first see if it has been resolved in a service release.

Hi, our data can be null only momentarily and does get updated, but the grouping coninues to be empty many times inspite of data refresh. So we end up seeing data grouped under none/empty/null when they actually have values.

So your data is null for only a short time before it is updated again to a legitimate value?  Are you updating existing records to null or are you adding new records that have null values in them?  If you are adding new records and you have not implemented INotifyPropertyChanged on the underlying properties, the XamDataGrid is going to use whatever the initial value is of the record.  If you change the property value later the grid is not going to refresh it. 

If you have INotifyPropertyChanged implemented though, setting the value to null and then later changing it to a non-null value should update the grouping.  Not implementing INotifyPropertyChanged is the only reason I can think of as to why the grouping is not updated.  Even in my sample, if I set the cell value to null, the record is moved to the null group and if I change it back to a valid value half a second later, it is removed from the null group as expected.

I really need a sample from you that reproduces this issue in order to be able to investigate this as I can't reproduce it in my own sample.  I first recommend that you update to the latest version of 14.1.

Hi Rob,

as I said that this issue occours occasionally and in general grouping works fine. all our entity objects and view models implement INotifyPropertyChanged. In many case initial values are null but are later updated, in other cases Initial values are not null but maybe updated to null momentarily.

We can see the data update in the grid, but in many cases groupings are not.

Unfortunately the code uses many third party libraries and its very difficult to create a sample.

Did you manage to download the 14.1.2261 service release?

14.1.20141.2062 is an older version.  We currently have 14.1.20141.2261 available which is a couple of versions ahead of yours.  Since I can't reproduce the issue on my end to confirm if this will actually fix it, I can't say for sure if this will do the trick or not.  But I recommend you update anyway just to be sure.  You can download it from your account on the Infragistics website.  Just click on your 14.1 product key and scroll down to the bottom of the page.  Then click on the Service Release tab.

we use version 14.1.20141.2062. Is that the service release?

No, What is that? does it fix this issue?

Have you tried updating to the latest service release for 14.1 yet?