Question

I have a query made using linq to SQL which result will be shown in a datagridview with sorting and filtering options.

public IQueryable RegresaDepositosBancarios()
        {
            var depositos = from d in context.depositos_bancarios
                            where d.Aplicado == false
                            orderby d.FechaDeposito ascending
                            select new
                            {
                                d.IDDeposito,
                                d.cuentas_bancarias.Nombre,
                                d.Monto,
                                d.FechaDeposito,
                                d.Observaciones
                            };
            return depositos    ;
        }

Later in my code I set the datasource to use previous result.

var depositos = operaciones.RegresaDepositosBancarios();
dataGrid_depositos.DataSource = depositos;

As you can see I’m returning and IQueryable of anonymous type and I can’t perform sorting or filtering over this. I read that you can implement a custom function to convert IQueryable to DataView and then use the RowFilter property, is this the more efficient way of doing it? Could be better to return other type in my function?

Any suggestions are welcome

Answer 1

You should change the return type from IQueryable to IEnumerable<dynamic>, then you can do something like:

 var over100 = RegresaDepositosBancarios()
    .Where(d => d.Monto > 100);

I think you could also code it this way (however I don’t normally use from so am not sure)

 var over100 = from d in RegresaDepositosBancarios()
    where d.Montho > 100;

Here’s a test program.

using System;
using System.Collections.Generic;
using System.Linq;

namespace ClassLibrary1
{
public class Class1
{
    public int A;
    public int B;
}

public class Test
{
    public static IEnumerable<dynamic> Build()
    {
        var list = new List<Class1>();
        list.Add(new Class1() { A = 10, B = 100 });
        list.Add(new Class1() { A = 200, B = 2000 });

        return list
            .OrderBy(e => e.B)
            .Select(e => new { A1 = e.A, B2 = e.B });
    }

    public static IEnumerable<dynamic> Filter()
    {
        return Build()
            .Where(e => e.A1 > 100);
    }

    static void Main()
    {
        foreach (dynamic e in Filter())
            Console.WriteLine("A1={0}, B2={1}", e.A1, e.B2);
    }
}

}