Select/unselect all options on group header

[Joan]

Hi all,

I must add a select all checkbox and an unselect all button to a RadGridView groups. The grouping is done by the user, the default view is a normal grid without groups, but the grouping option is enabled so the user can group the rows. The SelectionMode is set to Extended.
When the user has done so I must add a checkbox and a button to the header. First I suppose I'll have to edit the GroupHeaderTemplate or the GroupRowStyle (I still don't know which one) to add the checkbox and the button, that's not a problem. What I don't know how to do is selecting/unselecting only the rows that are part of that particular group.
Besides, when the user manually selects or unselects the checkbox IsChecked property must be refreshed.
How would I achieve that? I'm using MVVM, my ViewModel IsSelected property is already binded to the GridViewRow IsSelected property in TwoWay mode, that part works.

Thanks in advance,
-Tony

[Joan]

I've half-solved my problem.

Instead of having a checkbox it's just a button to select all. This means I don't need to keep track of the "all items selected" status. I've had to modify the GridViewGroupRowTemplate and use a Behavior.
This method works so far but it's just a temporary workaround, I'll need a checkbox in the future so I still need to know how I can know whether all items in a group are selected and be refreshed of this value.

Regards,
-Tony

[Milan]

Hello Tony,

Please take a look at this sample implementation.

Hope it helps.

Greetings,
Milan
the Telerik team

[Joan]

Hello Milan,

First, sorry about the late reply, I've been very busy with something else.

Your sample solves some issues, but there are still some problems. I wanted to check what happens with more than one item per group (but still more than one group), so I modified one method this way:

public static IList<Customer2> GetAll()
{
    return (from index in Enumerable.Range(1, 20)
            select new Customer2
            {
                ID = index,
                Age = 20,
                Name = "Customer " + (index % 4 + 1),
                JobCode = 1000 + index,
                City = "Halifax"

            }).ToList();
}

Note the "Name" line. This way I have 5 items per group when grouping by Name. Every time I use the checkbox on the Group header everything works well, the problem comes when I individually select or unselect an item, the group's checkbox isn't refreshed. The result is the attached image.

Basically, I need a way to receive a message every time an item selection changes from every group. Easier said than done. Maybe a mix of events and attached properties? I don't mind inheriting RadGridView if I must, in fact, I've already done so.

Thanks,
Tony

EDIT: I attached a different image than intended and I can't remove an attachment. The correct file is "GroupRefreshProblem.png".

[Milan]

Hi Tony,

That ca be fixed by simply calling InitializeCheckState in the 

GridView_SelectionChanged event handler in GroupSelectionBehavior

Best wishes,
Milan
the Telerik team

[Oliver]

Hi,

I found another refresh problem :(

check all group checkboxes, expand a group to make the last group dissapear over the bottom display area, unexpand all groups and now some group checkboxes becomed unchecked!!!

Thank's