Linq 找到所有具有特定类型的

Question

Is there a way to find in a List all items of a certain type with a Linq/Lambda expression?

Update: Because of the answers, I realize the question wasn't specific enough. I need a new List with only the items of a specific type. In my case, the class hasn't got any subclasses, so no need to take inheritance into account.

Answer 1

Use OfType<T> like so:

foreach (var bar in MyList.OfType<Foo>()) {
    ...
}

Answer 2

这样可以吗？

list.Where(t => t is MyType);

Answer 3

Something like this (if using Linq to objects - it won't work with Linq to entities):

var specificListOfTypes = from item in list
                            where item.GetType() == typeof(int)
                            select item;

Answer 4

maybe you could use ...

        List<object> list = new List<object>();
        list.Add("string");
        list.Add(9);

        var allOfOneType = list.Where(i => i.GetType().Equals(typeof(string)));

Answer 5

I suggest using this var myLst = new List<object>(); var elements = myList.Where(item => item.GetType().IsInstanceOfType(typeof(MyClass))); var myLst = new List<object>(); var elements = myList.Where(item => item.GetType().IsInstanceOfType(typeof(MyClass)));

Answer 6

You can use the GetType() method and compare with the specified type.

For instance , I select all values of the string type from the list below:

   var myList = new List<object>();

        myList.Add(5);

        myList.Add("My life");

        var result = from obj in myList
                     where obj.GetType() == typeof(string)
                     select obj;