private static IQueryable OrderByKey(this IQueryable queryable, bool ascending)
{
if (queryable == null)
{
throw new ArgumentNullException("queryable");
}
Expression orderedExpression = queryable.Expression;
Type queryableElementType = queryable.ElementType;
ParameterExpression parameter = queryable.CreateParameterExpression();
MemberExpression sortMemberExpression = QueryableExtensions.GenerateMemberExpression(parameter, "Key");
string methodName = (ascending) ? "OrderBy" : "OrderByDescending";
orderedExpression = Expression.Call(typeof(Queryable),
methodName,
new Type[] { queryableElementType, sortMemberExpression.Type },
orderedExpression, Expression.Quote(Expression.Lambda(sortMemberExpression, parameter)));
return(queryable.Provider.CreateQuery(orderedExpression));
}
internal static IQueryable OrderBy(
this IQueryable queryable,
SortDescriptionCollection implicitSortDescriptions,
SortDescriptionCollection explicitSortDescriptions,
bool reverse)
{
if (queryable == null)
{
throw new ArgumentNullException("queryable");
}
if ((implicitSortDescriptions == null) && (explicitSortDescriptions == null))
{
return(queryable);
}
Expression orderedExpression = queryable.Expression;
Type queryableElementType = queryable.ElementType;
ParameterExpression[] parameters = new ParameterExpression[] { Expression.Parameter(queryableElementType, "") };
string ascendingOrderByMethodName = "OrderBy";
string descendingOrderByMethodName = "OrderByDescending";
if (explicitSortDescriptions != null)
{
foreach (SortDescription sortDescription in explicitSortDescriptions)
{
MemberExpression sortMemberExpression = QueryableExtensions.GenerateMemberExpression(parameters[0], sortDescription.PropertyName);
string methodNameToUse;
if ((sortDescription.Direction == ListSortDirection.Ascending && !reverse) || (sortDescription.Direction == ListSortDirection.Descending && reverse))
{
methodNameToUse = ascendingOrderByMethodName;
}
else
{
methodNameToUse = descendingOrderByMethodName;
}
orderedExpression = Expression.Call(typeof(Queryable),
methodNameToUse,
new Type[] { queryableElementType, sortMemberExpression.Type },
orderedExpression, Expression.Quote(Expression.Lambda(sortMemberExpression, parameters)));
ascendingOrderByMethodName = "ThenBy";
descendingOrderByMethodName = "ThenByDescending";
}
}
if (implicitSortDescriptions != null)
{
foreach (SortDescription sortDescription in implicitSortDescriptions)
{
MemberExpression sortMemberExpression = QueryableExtensions.GenerateMemberExpression(parameters[0], sortDescription.PropertyName);
string methodNameToUse;
if ((sortDescription.Direction == ListSortDirection.Ascending && !reverse) || (sortDescription.Direction == ListSortDirection.Descending && reverse))
{
methodNameToUse = ascendingOrderByMethodName;
}
else
{
methodNameToUse = descendingOrderByMethodName;
}
orderedExpression = Expression.Call(typeof(Queryable),
methodNameToUse,
new Type[] { queryableElementType, sortMemberExpression.Type },
orderedExpression, Expression.Quote(Expression.Lambda(sortMemberExpression, parameters)));
ascendingOrderByMethodName = "ThenBy";
descendingOrderByMethodName = "ThenByDescending";
}
}
return(queryable.Provider.CreateQuery(orderedExpression));
}
