C# How to parse an Object[] to find all List<Int> objects using Linq?

Question

Using Linq in C#, how would you query an Object[] ( data ) so that it returns all List<int> objects in the array and flattens them into a single List<int> ?

This is what I tried, but for some reason it is not working:

List<int> IntData;

IntData = data.Where(n => n.GetType().IsGenericType)
              .Where(n => n.GetType().GetGenericTypeDefinition() == typeof(List<int>))
              .Select(n => (List<int>) n)
              .SelectMany( n => n));

Answer 1

You can use Linq's OfType method to do this:

List<int> IntData = data.OfType<List<int>>()
                        .SelectMany(i => i)
                        .ToList();

You could even make it more generic to accept any IEnumerable<int> :

List<int> IntData = data.OfType<IEnumerable<int>>()
                        .SelectMany(i => i)
                        .ToList();

Answer 2

我现在打电话的编辑能力有限，但我认为这可以满足您的需求：

data.OfType<List<int>>().SelectMany(x=>x).ToList();