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copied!<p>Read this great post on DLINQ by ScottGu</p> <p><a href="http://weblogs.asp.net/scottgu/archive/2008/01/07/dynamic-linq-part-1-using-the-linq-dynamic-query-library.aspx" rel="nofollow noreferrer">Dynamic LINQ (Part 1: Using the LINQ Dynamic Query Library)</a> </p> <p>You would need something like</p> <pre><code>var product = myobject.Where("Cost <= 10000"); var product = myobject.Where("Name = @0", strName); </code></pre> <p>If you downloaded the samples you need to find the <code>Dynamic.cs</code> file in the sample. You need to copy this file into your project and then add <code>using System.Linq.Dynamic;</code> to the class you are trying to use Dynamic Linq in.</p> <p>EDIT: To answer your edit. Yes, there is of course a performance difference. If you know the variations of filters beforehand then I would suggest writing them out without using DLINQ. </p> <p>You can create your own Extension Method like so.</p> <pre><code> public static class FilterExtensions { public static IEnumerable<T> AddFilter<T,T1>(this IEnumerable<T> list, Func<T,T1, bool> filter, T1 argument ) { return list.Where(foo => filter(foo, argument) ); } } </code></pre> <p>Then create your filter methods.</p> <pre><code> public bool FilterById(Foo obj, int id) { return obj.id == id; } public bool FilterByName(Foo obj, string name) { return obj.name == name; } </code></pre> <p>Now you can use this on an <code>IEnumerable<Foo></code> very easily.</p> <pre><code> List<Foo> foos = new List<Foo>(); foos.Add(new Foo() { id = 1, name = "test" }); foos.Add(new Foo() { id = 1, name = "test1" }); foos.Add(new Foo() { id = 2, name = "test2" }); //Example 1 //get all Foos's by Id == 1 var list1 = foos.AddFilter(FilterById, 1); //Example 2 //get all Foo's by name == "test1" var list2 = foos.AddFilter(FilterByName, "test1"); //Example 3 //get all Foo's by Id and Name var list1 = foos.AddFilter(FilterById, 1).AddFilter(FilterByName, "test1"); </code></pre>

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