I want to write a method which searches for an object in my list, which can contain multiple inherited types.

public class MyClass 
{
   public readonly List<parentType> objects = new List<parentType>();

   public parentType GetObject(Type type, string tag)
   {
       foreach (parentType _object in objects)
       {
           if (_object.GetType() == type)
           {
                if (tag == _object.tag)
                {
                    return _object;
                }
            }
        }
        return null;
    }
}

But when I call .GetObject(childType, "tag") I get CS0119: 'childType' is a type, which is not valid in the given context.

What should I do? Thanks.

CodePudding user response：

You have several possibilities here:

• use typeof - GetObject(typeof(childType), "tag")

• rewrite your function in generic way and use type as generic parameter

  public parentType GetObject<T>(string tag) where T: parentType
  {
    //use T as the type to search
  }
  

  and then call it GetObject<childType>("tag");

  In some cases it may be also usefull to use generic parameter to return more concrete type

  T GetObject<T>(string tag) where T: parentType
  {
  }
  

  Moreover (but a little offtopic) you can use LINQ to get more simple and idiomatic solution

  public T GetObject<T>(string tag) where T: parentType
  {
    return objects.OfType<T>().FirstOrDefault(obj => obj.tag == tag);
  }