void SetPropertyDescription(int i, string name, ListSortDirection direction)
{
sortDescriptions[i] = new DynamicSortDescription()
{
Direction = direction,
NameChain = name.Split('.')
};
List <PropertyInfo> props = new List <PropertyInfo>();
Type type = typeof(T);
for (int j = 0; j < sortDescriptions[i].NameChain.Length; ++j)
{
PropertyInfo prop = type.GetProperty(sortDescriptions[i].NameChain[j]);
if (prop == null)
{
break;
}
props.Add(prop);
type = prop.PropertyType;
}
sortDescriptions[i].PropertyChain = props.ToArray();
}
int AscendingCompare(DynamicSortDescription sort_description, T x, T y)
{
//initially left and right are objects of type derived from T
object left = x;
object right = y;
for (int j = 0; j < sort_description.NameChain.Length; ++j)
{
PropertyInfo left_prop;
PropertyInfo right_prop;
if (j < sort_description.PropertyChain.Length)
{
PropertyInfo prop = sort_description.PropertyChain[j];
left_prop = prop;
right_prop = prop;
}
else
{
string prop_name = sort_description.NameChain[j];
left_prop = left.GetType().GetProperty(prop_name);
right_prop = right.GetType().GetProperty(prop_name);
}
left = left_prop != null?left_prop.GetValue(left, null) : null;
right = right_prop != null?right_prop.GetValue(right, null) : null;
if (left == null || right == null)
{
if (left == null && right == null)
{
return(0);
}
if (left == null)
{
return(-1); //nulls goes first
}
return(1);
}
}
IComparable left_comp = left as IComparable;
return(left_comp.CompareTo(right));
}