Creating Dymamic Method throws en 异常

问：

我想创建一些具有 2 个周期的动态方法：首先将一些 N 值推送到评估堆栈上，其次 - 这些 N 值从堆栈中弹出。但 CreateMethod 会引发 InvalidProgramException。我怎样才能实现我想要什么？ 我的代码是：

public static Action MakeSimpleAction()
{
    var dm = new DynamicMethod("evil", typeof(void), new Type[] {  }, true);
    var il = dm.GetILGenerator(); Label startCycle;
    il.DeclareLocal(typeof(int));   //i = 0

    //Method 1: All is OK!
    //il.Emit(OpCodes.Ldc_I4_0);  //Push 0 onto evaluation stack
    //il.Emit(OpCodes.Pop);  //Pop value from evaluation stack
    //il.Emit(OpCodes.Ret);

    //Method 2: In cycles - throws an exception!

    //First cycle: for (int i = 0; i < 5; i ++) Push(0);
    il.Emit(OpCodes.Ldc_I4_0); il.Emit(OpCodes.Stloc_0);    //i = 0
    il.MarkLabel(startCycle = il.DefineLabel());
    il.Emit(OpCodes.Ldc_I4_0);  //Push 0 onto evaluation stack
    
    il.Emit(OpCodes.Ldloc_0);   //i ++
    il.Emit(OpCodes.Ldc_I4_1);
    il.Emit(OpCodes.Add);
    il.Emit(OpCodes.Stloc_0);
    //if i < 5 goto startCycle
    il.Emit(OpCodes.Ldloc_0);
    il.Emit(OpCodes.Ldc_I4_5);
    il.Emit(OpCodes.Clt);   //if i < 5
    il.Emit(OpCodes.Brtrue_S, startCycle);

    //Second cycle: for (int i = 0; i < 5; i ++) Pop();
    il.Emit(OpCodes.Ldc_I4_0); il.Emit(OpCodes.Stloc_0);    //i = 0
    il.MarkLabel(startCycle = il.DefineLabel());
    il.Emit(OpCodes.Pop);  //Pop value from evaluation stack

    il.Emit(OpCodes.Ldloc_0);   //i ++
    il.Emit(OpCodes.Ldc_I4_1);
    il.Emit(OpCodes.Add);
    il.Emit(OpCodes.Stloc_0);
    //if i < 5 goto startCycle
    il.Emit(OpCodes.Ldloc_0);
    il.Emit(OpCodes.Ldc_I4_5);
    il.Emit(OpCodes.Clt);   //if i < 5
    il.Emit(OpCodes.Brtrue_S, startCycle);

    il.Emit(OpCodes.Ret);

    //throw System.InvalidProgramException: 'Common Language Runtime detected an invalid program.'
    return (Action)dm.CreateDelegate(typeof(Action));
}