public void OrderByDescending_AddSortExpressionValidation()
{
var(table, one, two, three) = InstantiateTable();
EnumerableRowCollection <DataRow> source = table.Cast <DataRow>();
var orderedBackwards = source.OrderByDescending(row => int.Parse((string)row.ItemArray[0]));
Assert.Equal(new DataRow[] { three, two, one }, orderedBackwards);
DataRow four = table.Rows.Add(4);
var comparedBackwards = source.OrderByDescending((row => row), new TestDataRowComparer <DataRow>());
Assert.Equal(new DataRow[] { four, three, two, one }, comparedBackwards);
}
/// <summary>
/// LINQ's OrderByDescending operator for generic EnumerableRowCollection.
/// </summary>
public static OrderedEnumerableRowCollection <TRow> OrderByDescending <TRow, TKey>(this TypedTableBase <TRow> source, Func <TRow, TKey> keySelector) where TRow : DataRow
{
DataSetUtil.CheckArgumentNull(nameof(source), "source");
EnumerableRowCollection <TRow> erc = new EnumerableRowCollection <TRow>(source);
return(erc.OrderByDescending(keySelector));
}