public static IQueryable <T> OrderBy <T>(this IQueryable <T> queryable, OrderQuery order) where T : class
{
Type type = typeof(T);
if (order != null)
{
var orderParams = order.GetOrderParams();
if (orderParams != null && orderParams.Length > 0)
{
int i = 0;
foreach (var orderExpr in orderParams)
{
PropertyInfo property = type.GetProperty(orderExpr.PropertyName);
if (property == null)
{
throw new ArgumentException("propertyName", "Not Exist");
}
ParameterExpression param = Expression.Parameter(type, "p");
Expression propertyAccessExpression = Expression.MakeMemberAccess(param, property);
LambdaExpression orderByExpression = Expression.Lambda(propertyAccessExpression, param);
string methodName = orderExpr.OrderType == OrderType.ASC ? (i == 0 ? "OrderBy" : "ThenBy") : (i == 0 ? "OrderByDescending" : "ThenByDescending");
MethodCallExpression resultExp = Expression.Call(typeof(Queryable), methodName, new Type[] { type, property.PropertyType }, queryable.Expression, Expression.Quote(orderByExpression));
queryable = queryable.Provider.CreateQuery <T>(resultExp);
i++;
}
}
}
return(queryable);
}
