Native Dynamic Linq (C #)

Question

Native Dynamic Linq (C #)

Can I use a keyword dynamic

in C # 5.0 (.Net 4.5) to create a dynamic LINQ query?

I know this is possible using third party libraries, but this is not practical right now.

The easiest way to illustrate my point is with an example:

    class test
    {
        public int i { get; set; }
    }

    void Foo()
    {
        var collection = new[] { new test() { i = 1 }, new test() { i = 2 } };
        Bar(collection);
    }

    void Bar<T>(IEnumerable<T> collection)
    {
        //this works
        foreach (dynamic item in collection)
            if (item.i == 2)
            {
                //do something
            }

        //this does not - although this is what id like to use
        foreach (dynamic item in collection.Where(a => a.i == 2))
        {
            //do something
        }
    }

Edit for each request: Throws a compiler error -

'T' does not contain a definition for 'i' and no extension method 'i' can be found that takes a first argument of type 'T' (are you missing a using directive or an assembly reference?)

+3

c # dynamic

maxp Jan 31. 13 at 10:37

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1 answer

mathieu · Answer 1 · 2013-01-31T10:48:36+0000

Replace the T declaration in Bar to use dynamic:

void Bar(IEnumerable<dynamic> collection)
{
    //this works
    foreach (dynamic item in collection)
        if (item.i == 2)
        {
            //do something
        }

    //this does compile
    foreach (dynamic item in collection.Where(a => a.i == 2))
    {
        //do something
    }
}

Native Dynamic Linq (C #)

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