How do I check if a given value is a generic list?

public bool IsList(object value)
    {
        Type type = value.GetType();
        // Check if type is a generic list of any type
    }

What's the best way to check if the given object is a list, or can be cast to a list?

From stackoverflow

• Probably the best way would be to do something like this:

  IList list = value as IList;
  
  if (list != null)
  {
      // use list in here
  }
  

  This will give you maximum flexibility and also allow you to work with many different types that implement the IList interface.

  Lucas : this does not check if it a *generic* list as asked.

• if(value is IList && value.GetType().GetGenericArguments().Length > 0)
  {
  
  }
  

  ScottS : I think you need a call to GetType() e.g. value.GetType().GetGenericArguments().Length > 0

  BFree : Oops, you're right. My mistake.

• Maybe you find answer here http://stackoverflow.com/questions/755200/how-do-i-detect-that-an-object-is-a-generic-collection-and-what-types-it-contain

• if(value is IList && value.GetType().IsGenericType) {
  
  }
  

  James Couvares : You need to add using System.Collections; on top of your source file. The IList interface I suggested is NOT the generic version (hence the second check)

•  bool isList = o.GetType().IsGenericType 
                  && o.GetType().GetGenericTypeDefinition() == typeof(IList<>));
  

• public bool IsList(object value) {
      return value is IList 
          || IsGenericList(value);
  }
  
  public bool IsGenericList(object value) {
      var type = value.GetType();
      return type.IsGenericType
          && typeof(List<>) == type.GetGenericTypeDefinition();
  }
  

• For you guys that enjoy the use of extension methods:

  public static bool IsGenericList(this object o)
  {
      bool isGenericList = false;
  
      var oType = o.GetType();
  
      if (oType.IsGenericType && (oType.GetGenericTypeDefinition() == typeof(List<>)))
       isGenericList = true;
  
      return isGenericList;
  }
  

  So, we could do:

  if(o.IsGenericList())
  {
   //...
  }