// 
// Sample code to show late-bound set value on array
// Written by Haibo Luo @ http://blogs.msdn.com/haibo_luo
// 
// THIS CODE IS PROVIDED "AS IS", WITH NO WARRANTIES INTENDED OR IMPLIED. USE AT YOUR OWN RISK
//

using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Security.Permissions;

//[assembly: SecurityPermission(SecurityAction.RequestRefuse, SkipVerification = true)]

class Test {
    static void Main() {
        ZeroLowerBound1DArray();
        NonZeroLowerBound1DArray();
    }

    delegate void MySetValue(Array array, int index, int value);

    static void ZeroLowerBound1DArray() {
        // creation: new int[5]
        Array x = Array.CreateInstance(typeof(int), 5);

        // 0. early-bind set: explicit cast to int[]
        int[] y = (int[])x;
        y[0] = 100;

        // 1. late-bound set via Array.SetValue
        x.SetValue(200, 1);

        // 2. late-bound set via DynamicMethod/Delegate/OpCodes.Stelem
        DynamicMethod dm = new DynamicMethod("SetValueByStelem", typeof(void),
            new Type[] { typeof(Array), typeof(int), typeof(int) }, typeof(Test));
        ILGenerator ilgen = dm.GetILGenerator();
        ilgen.Emit(OpCodes.Ldarg_0);
        ilgen.Emit(OpCodes.Castclass, x.GetType());
        ilgen.Emit(OpCodes.Ldarg_1); // index
        ilgen.Emit(OpCodes.Ldarg_2); // value
        ilgen.Emit(OpCodes.Stelem_I4);
        ilgen.Emit(OpCodes.Ret);
        MySetValue sv = (MySetValue)dm.CreateDelegate(typeof(MySetValue));

        sv(x, 2, 300);

        // 3. late-bound set via MethodInfo.Invoke of "Set"
        MethodInfo mi = x.GetType().GetMethod("Set");

        mi.Invoke(x, new object[] { 3, 400 });

        // 4. late-bound set via DynamicMethod/Delegate/"Set"
        dm = new DynamicMethod("SetValueBySet", typeof(void),
           new Type[] { typeof(Array), typeof(int), typeof(int) }, typeof(Test));

        ilgen = dm.GetILGenerator();
        ilgen.Emit(OpCodes.Ldarg_0);
        ilgen.Emit(OpCodes.Castclass, x.GetType());
        ilgen.Emit(OpCodes.Ldarg_1);
        ilgen.Emit(OpCodes.Ldarg_2);
        ilgen.Emit(OpCodes.Call, mi);
        ilgen.Emit(OpCodes.Ret);

        sv = (MySetValue)dm.CreateDelegate(typeof(MySetValue));
        sv(x, 4, 500);

        Array.ForEach(y, delegate(int a) { Console.WriteLine(a); });
    }

    static void NonZeroLowerBound1DArray() {
        // creation: new int[-3..1]
        Array x = Array.CreateInstance(typeof(int), new int[] { 5 }, new int[] { -3 });

        // 1. late-bound set via Array.SetValue
        x.SetValue(200, 1 - 3);

        // 3. late-bound set via MethodInfo.Invoke of "Set"
        MethodInfo mi = x.GetType().GetMethod("Set");
        mi.Invoke(x, new object[] { 3 - 3, 400 });

        // 4. late-bound set via DynamicMethod/Delegate/"Set"
        DynamicMethod dm = new DynamicMethod("SetValueBySet", typeof(void),
           new Type[] { typeof(Array), typeof(int), typeof(int) }, typeof(Test));

        ILGenerator ilgen = dm.GetILGenerator();
        ilgen.Emit(OpCodes.Ldarg_0);
        ilgen.Emit(OpCodes.Castclass, x.GetType());
        ilgen.Emit(OpCodes.Ldarg_1);
        ilgen.Emit(OpCodes.Ldarg_2);
        ilgen.Emit(OpCodes.Call, mi);
        ilgen.Emit(OpCodes.Ret);

        MySetValue sv = (MySetValue)dm.CreateDelegate(typeof(MySetValue));
        sv(x, 4 - 3, 500);

        for (int i = -3; i < 2; i++) {
            Console.WriteLine(x.GetValue(i));
        }
    }

    static void MultiDimensionalArray() {
        int[,] array = new int[2, 2];
        array[0, 1] = 1000;
    }
}