如何使用反射调用泛型类型的属性/字段

Question

Consider Following class

class A<T> where T:new()
{
  public static T Instance = new T();
  A()
  {
  }
}

I have 2 questions

1. I need Instance object with Reflection. I have tried following

    var type = typeof(A<int>); // var type = typeof(A<>).MakeGenericType(typeof(int)); // Also tried this var instanceMember1 = type.GetMember("Instance", BindingFlags.Static ); // returns null var instanceMember2 = type.GetField("Instance", BindingFlags.Static ); // returns null 

   I have also tried to Change Instance to property and call GetProperty with no success.

2. After removing new() constraint and making constructor private, How to invoke private (parameterless) constructor through reflection.

Answer 1

Add BindingFlags.Public to your flags for GetField .

var instanceMember1 = type.GetField("Instance", BindingFlags.Static |
    BindingFlags.Public);

To invoke the private constructor:

var ctor = type.GetConstructor(BindingFlags.Instance | BindingFlags.NonPublic, 
    null, Type.EmptyTypes, new ParameterModifier[0]);
var instance = ctor.Invoke(null) as A<int>;