internal override void RefreshDistinctValuesForField(DataGridItemPropertyBase dataGridItemProperty)
{
if (dataGridItemProperty == null)
{
return;
}
if (dataGridItemProperty.CalculateDistinctValues == false)
{
return;
}
// List containing current column distinct values
HashSet <object> currentColumnDistinctValues = new HashSet <object>();
ReadOnlyObservableHashList readOnlyColumnDistinctValues = null;
// If the key is not set in DistinctValues yet, do not calculate distinct values for this field
if (!(( DistinctValuesDictionary )this.DistinctValues).InternalTryGetValue(dataGridItemProperty.Name, out readOnlyColumnDistinctValues))
{
return;
}
ObservableHashList columnDistinctValues = readOnlyColumnDistinctValues.InnerObservableHashList;
// We use the DistinctValuesSortComparer if present, else the SortComparer for the DataGridItemProperty, else,
// the Comparer used is the one of the base class.
IComparer distinctValuesSortComparer = dataGridItemProperty.DistinctValuesSortComparer;
if (distinctValuesSortComparer == null)
{
distinctValuesSortComparer = dataGridItemProperty.SortComparer;
}
using (columnDistinctValues.DeferINotifyCollectionChanged())
{
DataGridVirtualizingQueryableCollectionViewGroupRoot rootGroup = this.RootGroup as DataGridVirtualizingQueryableCollectionViewGroupRoot;
Debug.Assert(rootGroup != null);
object[] distinctValues = rootGroup.GetItemPropertyDistinctValues(dataGridItemProperty);
foreach (object distinctValue in distinctValues)
{
// Compute current value to be able to remove unused values
currentColumnDistinctValues.Add(distinctValue);
}
DataGridCollectionViewBase.RemoveUnusedDistinctValues(
distinctValuesSortComparer, currentColumnDistinctValues, columnDistinctValues, null);
}
}
private IQueryable SortQueryable(IQueryable queryable, bool reverseSort)
{
DataGridVirtualizingCollectionViewBase parentCollectionView = this.GetCollectionView();
Debug.Assert(parentCollectionView != null);
SortDescriptionCollection explicitSortDescriptions = parentCollectionView.SortDescriptions;
ListSortDirection directionToUseForImplicitSortDescriptions = ListSortDirection.Ascending;
if (explicitSortDescriptions.Count > 0)
{
directionToUseForImplicitSortDescriptions = explicitSortDescriptions[explicitSortDescriptions.Count - 1].Direction;
}
SortDescriptionCollection implicitSortDescriptions = new SortDescriptionCollection();
DataGridVirtualizingQueryableCollectionViewGroupRoot groupRoot =
parentCollectionView.RootGroup as DataGridVirtualizingQueryableCollectionViewGroupRoot;
Debug.Assert(groupRoot != null);
string[] primaryKeys = groupRoot.PrimaryKeys;
if (primaryKeys != null)
{
for (int i = 0; i < primaryKeys.Length; i++)
{
string primaryKey = primaryKeys[i];
Debug.Assert(!string.IsNullOrEmpty(primaryKey));
implicitSortDescriptions.Add(new SortDescription(primaryKey, directionToUseForImplicitSortDescriptions));
}
}
return(queryable.OrderBy(implicitSortDescriptions, explicitSortDescriptions, reverseSort));
}
