NewSlot and ReuseSlot

namespace CSharpTester
{
    class Program
    {
        static void Main(string[] args)
        {
            var methodA = typeof(A).GetMethod("Test");
            PrintAttributes(typeof(System.Reflection.MethodAttributes), (int)methodA.Attributes);

            var methodB = typeof(B).GetMethod("Test");
            PrintAttributes(typeof(System.Reflection.MethodAttributes), (int)methodB.Attributes);
        }
        public static void PrintAttributes(Type attribType, int iAttribValue)
        {
            if (!attribType.IsEnum) { Console.WriteLine("This type is not an enum."); return; }

            FieldInfo[] fields = attribType.GetFields(BindingFlags.Public | BindingFlags.Static);
            for (int i = 0; i < fields.Length; i++)
            {
                int fieldvalue = (Int32)fields[i].GetValue(null);
                if ((fieldvalue & iAttribValue) == fieldvalue)
                {
                    Console.WriteLine(fields[i].Name);
                }
            }
        }
    }
    public interface IA
    {
        void Test();

        void Test1();
    }
    public class A : IA
    {
        public void Test() { Console.WriteLine(1); }
        void IA.Test1() { Console.WriteLine(1); }
        public void Test2() { Console.WriteLine(1); }
        public void Test3() { Console.WriteLine(1); }
        public void Test4() { Console.WriteLine(1); }
        public void Test5() { Console.WriteLine(1); }
    }
    public class B : IA
    {
        public void A1() { Console.WriteLine(1); }
        public void A2() { Console.WriteLine(1); }
        public void A3() { Console.WriteLine(1); }
        public void Test() { Console.WriteLine(1); }
        public void Test1() { Console.WriteLine(1); }
        public void Test2() { Console.WriteLine(1); }
    }


}

 

 

两个类A，B 继承接口IA，都实现方法Test

以下是运行结果

 

两个都出现了newslot 和reuseslot，结论是都重用了同样的slot，继承以后所有父类，接口的槽的位置不变

以下是这两个的定义

	ReuseSlot	Indicates that the method will reuse an existing slot in the vtable. This is the default behavior.
	NewSlot	Indicates that the method always gets a new slot in the vtable.

url：http://msdn.microsoft.com/en-us/library/system.reflection.methodattributes.aspx

(我的理解就是 有newslot的 说明在当前类型有实现了，否则就在父类或者外部；有reuseslot的就说明该方法必然是重写或者继承自父类，当然方法偏移量应该是要一致的)

如果某个类并没有实现某个方法，而是继承自其父类的实现

那么newslot为false  而reuseslot为true

以下是代码

namespace CSharpTester
{
    class Program
    {
        static void Main(string[] args)
        {
            var methodA = typeof(A).GetMethod("A1");

            PrintAttributes(typeof(System.Reflection.MethodAttributes), (int)methodA.Attributes);
        }
        public static void PrintAttributes(Type attribType, int iAttribValue)
        {
            if (!attribType.IsEnum) { Console.WriteLine("This type is not an enum."); return; }

            FieldInfo[] fields = attribType.GetFields(BindingFlags.Public | BindingFlags.Static);
            for (int i = 0; i < fields.Length; i++)
            {
                int fieldvalue = (Int32)fields[i].GetValue(null);
                if ((fieldvalue & iAttribValue) == fieldvalue)
                {
                    Console.WriteLine(fields[i].Name);
                }
            }
        }
    }
    public class A : B
    {
    }
    public class B
    {
        public void A1() { Console.WriteLine(1); }
    }
}

以下是运行结果，有ReuseSlot 没有NewSlot

 

 

 

多继承接口的情况下，还需要进一步分析