[Solved] why did not foreach GroupDescriptors,upgrade offical version Q3

[jerome]

hi,
this is ok in version 924 ,the code as follows:

List<string> groupColumns = new List<string>();

              foreach (GroupDescriptor group in dataGrid.GroupDescriptors)
              {
                  if (!string.IsNullOrEmpty(columnaList))
                  {
                      columnaList += "," + group.Member;
                  }
                  else
                  {
                      columnaList += group.Member;
                  }
                  groupColumns.Add(group.Member);
              }

upgraded q3,  throw exception message: 
Unable to cast object of type 'Telerik.Windows.Controls.GridView.ColumnGroupDescriptor' to type 'Telerik.Windows.Data.GroupDescriptor'.

since 924 is ok.

Do not understand

we have other code for it. load GroupDescriptor for save data.

GroupDescriptor descriptor = new GroupDescriptor();
 if (pair.Key == "SecID")
 {
     CountFunction countFunction = new CountFunction { Caption = "Count:" };
     holdingColumn.FooterTextAlignment = TextAlignment.Left;

     holdingColumn.AggregateFunctions.Add(countFunction);
     descriptor.AggregateFunctions.Add(countFunction);
 }

then  so  to do..    add  descriptor  to datagrid

if (groupByData.ContainsKey(SelectedTabIndexer))
            {
                if (groupByData[SelectedTabIndexer].Contains(columnName))
                {
                    descriptor.Member = columnName;
                    descriptor.DisplayContent = displaycontent;
                    SelectedDataGrid.GroupDescriptors.Add(descriptor);
                }
            }

OK,  SelectedDataGrid.GroupDescriptors.Count() > 0 
if changed code use ColumnGroupDescriptor  :

foreach (ColumnGroupDescriptor group in dataGrid.GroupDescriptors)
{
    if (!string.IsNullOrEmpty(columnaList))
    {
        columnaList += "," + group.Column.UniqueName;
    }
    else
    {
        columnaList += group.Column.UniqueName;
    }
    groupColumns.Add(group.Column.UniqueName);
}

 
throw exception message:
Unable to cast object of type 'Telerik.Windows.Data.GroupDescriptor' to type 'Telerik.Windows.Controls.GridView.ColumnGroupDescriptor'.

why ?  both  Telerik.Windows.Data.GroupDescriptor and  Telerik.Windows.Controls.GridView.ColumnGroupDescriptor  did not foreach?

any question?

thanks

[Yavor Georgiev]

Hello jerome,

 This happens because there appear to be both GroupDescriptors and ColumnGroupDescriptors in the GroupDescriptors collection of RadGridView. You need to use the OfType<> extension method (found in the System.Linq namespace) in order to filter the GroupDescriptors collection to only GroupDescriptors or ColumnGroupDescriptors.

Kind regards,
Yavor Georgiev
the Telerik team

[jerome]

oh,

Thank you very much

[Gaurang]

Hi I think I have same problem with my code when I updated new dll of telrik now it is not working please reply me.
My code is here

sortOptions.Add(gridView.GroupDescriptors);

 

 

 

 

public void Add(GroupDescriptorCollection groupDescriptorCollection)

 

 

{

 

 

 

foreach (GroupDescriptor groupDescriptor in groupDescriptorCollection) //gives error here

 

{

if(groupDescriptor.SortDirection == ListSortDirection.Ascending)

 

{

 

this.SortCriteriaList.Add(new SortCriteria(groupDescriptor.Member, SortOrder.Ascending));
}

 

 

 

 

else if (groupDescriptor.SortDirection == ListSortDirection.Descending)
{
this.SortCriteriaList.Add(new SortCriteria(groupDescriptor.Member, SortOrder.Descending));

 

 

}

 

 

 

 

}

}

it gives me error like
Unable to cast object of type 'Telerik.Windows.Controls.GridView.ColumnGroupDescriptor' to type 'Telerik.Windows.Data.GroupDescriptor'.

Gaurang Vaishnav

[jerome]

you can use code like  below:

foreach (ColumnGroupDescriptor group in dataGrid.GroupDescriptors.OfType<ColumnGroupDescriptor>())

foreach (GroupDescriptor group in dataGrid.GroupDescriptors.OfType<GroupDescriptor>())

[Gaurang]

Thanks you for your reply now my problem is solved.

I tried this
foreach (GroupDescriptor group in dataGrid.GroupDescriptors.OfType<GroupDescriptor>)

So I was getting error on foreach because I missed to place () {braket} at end.

foreach (GroupDescriptor group in dataGrid.GroupDescriptors.OfType<GroupDescriptor>())

Gaurang Vaishnav