How do I specify the Linq OrderBy argument dynamically? [duplicate]

by

You can use a little bit of reflection to construct the expression tree as follows (this is an extension method):

public static IQueryable<TEntity> OrderBy<TEntity>(this IQueryable<TEntity> source, string orderByProperty,
                          bool desc) 
{
     string command = desc ? "OrderByDescending" : "OrderBy";
     var type = typeof(TEntity);
     var property = type.GetProperty(orderByProperty);
     var parameter = Expression.Parameter(type, "p");
     var propertyAccess = Expression.MakeMemberAccess(parameter, property);
     var orderByExpression = Expression.Lambda(propertyAccess, parameter);
     var resultExpression = Expression.Call(typeof(Queryable), command, new Type[] { type, property.PropertyType },
                                   source.Expression, Expression.Quote(orderByExpression));
     return source.Provider.CreateQuery<TEntity>(resultExpression);
}

orderByProperty is the Property name you want to order by and if pass true as parameter for desc, will sort in descending order; otherwise, will sort in ascending order.

Now you should be able to do existingStudents.OrderBy("City",true); or existingStudents.OrderBy("City",false);

More Related Contents:

  1. Simultaneous equations in C# LINQ [closed]
  2. Lambda statement for finding sub-string in a string from list of strings [closed]
  3. Returning IEnumerable vs. IQueryable
  4. Fluent and Query Expression — Is there any benefit(s) of one over other?
  5. ‘Contains()’ workaround using Linq to Entities?
  6. Is a LINQ statement faster than a ‘foreach’ loop?
  7. Using IQueryable with Linq
  8. LINQ Aggregate algorithm explained
  9. How to use a string to create a EF order by expression?
  10. How do I sort strings alphabetically while accounting for value when a string is numeric?
  11. Combination Generator in Linq
  12. How can I get the index of an item in a list in a single step?
  13. Distinct in Linq based on only one field of the table
  14. Query Microsoft Access MDB Database using LINQ and C#
  15. Performance of LINQ Any vs FirstOrDefault != null
  16. LINQ to find series of consecutive numbers
  17. Edit specific Element in XDocument
  18. Linq query with nullable sum
  19. Dynamic table name in linq [duplicate]
  20. Recursive LINQ query: select item and all children with subchildren
  21. C# Select elements in list as List of string
  22. Join and Include in Entity Framework
  23. Creating dynamic queries with entity framework
  24. How to merge a list of lists with same type of items to a single list of items?
  25. The data source does not support server-side data paging
  26. Last and LastOrDefault not supported
  27. Linq “Could not translate expression… into SQL and could not treat it as a local expression.”
  28. How to group by DateTime.Date in EntityFramework
  29. Explicit/implicit cast operator fails when using LINQ’s .Cast() operator
  30. Convert DataTable to Generic List in C#

Leave a Comment