学步园

由于该方法是针对自需求编写的,所以不一定适合你的需要,但对于想学习的朋友可以作一个参考.

 private void MethodGenerator(ILGenerator il, MethodInfo method)
        {
  
            Type[] types = GetParameterTypes(method.GetParameters());
            Type[] gtypes;
            MethodInfo callmethod;
            il.DeclareLocal(typeof(MethodBase));
            il.DeclareLocal(typeof(object[]));
            bool isvoid = method.ReturnType.ToString() == "System.Void";
            if (!isvoid)//定义返回值变量
            {
                il.DeclareLocal(GetType(method.ReturnType));
                
            }
            il.DeclareLocal(typeof(object[]));
            il.DeclareLocal(typeof(Type[]));
            il.Emit(OpCodes.Nop);
            callmethod = typeof(MethodBase).GetMethod("GetCurrentMethod", new Type[0]);
            il.Emit(OpCodes.Call, callmethod);
            il.Emit(OpCodes.Stloc_0);//把调用GetCurrentMethod的返回值封送到局部变量0里
            AddGenericTypes#region AddGenericTypes
            if (method.IsGenericMethod)//顶他个肺是泛型方法
            {
                gtypes = method.GetGenericArguments();//得到泛型参类型
                il.Emit(OpCodes.Ldc_I4, gtypes.Length);//加载数组长度
                il.Emit(OpCodes.Newarr, typeof(Type));//定义数组,并保存以下局部变量中
                if (!isvoid)
                    il.Emit(OpCodes.Stloc_S, 4);
                else
                    il.Emit(OpCodes.Stloc_3);
                for (int i = 0; i < gtypes.Length; i++)//这下把TM后面的运行时类型挖出来放到数据组中
                {
                    if (!isvoid)//加载相关局部变量
                        il.Emit(OpCodes.Ldloc_S, 4);
                    else
                        il.Emit(OpCodes.Ldloc_3);
                    il.Emit(OpCodes.Ldc_I4, i);//设置索引
                    il.Emit(OpCodes.Ldtoken, gtypes[i]);//封送类型
                    callmethod = typeof(Type).GetMethod("GetTypeFromHandle"
                        , new Type[] {typeof(RuntimeTypeHandle)});
                    il.Emit(OpCodes.Call, callmethod);//把运行时类型拖出来
                    il.Emit(OpCodes.Stelem_Ref);//把类型放进袋子里
                    
                }
            }
            else
            {
                il.Emit(OpCodes.Ldnull);//把null值封送到以下变量中
                if (!isvoid)
                   il.Emit(OpCodes.Stloc_S, 4);
                else
                  il.Emit(OpCodes.Stloc_3);
                
            }
            
            #endregion
            if (types.Length > 0)//存在方法参数
            {
                il.Emit(OpCodes.Ldc_I4, types.Length);//加载数组长度
                il.Emit(OpCodes.Newarr, typeof(object));//定义数组,并保存以下局部变量中
                if (!isvoid)
                   il.Emit(OpCodes.Stloc_3);
                
                else
                   il.Emit(OpCodes.Stloc_2);
                
                for (int i = 0; i < types.Length; i++)//将参数加载到局部变量数组里面
                {
                    if (!isvoid)
                        il.Emit(OpCodes.Ldloc_3);
                    else
                        il.Emit(OpCodes.Ldloc_2);
                    il.Emit(OpCodes.Ldc_I4, i);
                    il.Emit(OpCodes.Ldarg, i + 1);
                    if (types[i].IsValueType || types[i].IsGenericParameter || types[i].IsGenericType)
                    {
                        //是值类型,泛型参,泛型拖进来打包装箱
                        il.Emit(OpCodes.Box, GetType(types[i]));
                    }
                    il.Emit(OpCodes.Stelem_Ref);
                    
                }


                if (!isvoid)//加载相关局部变量
                    il.Emit(OpCodes.Ldloc_3);

                else
                    il.Emit(OpCodes.Ldloc_2);

                
            }
            else
            {
                il.Emit(OpCodes.Ldnull);
            }
           
            il.Emit(OpCodes.Stloc_1);
            il.Emit(OpCodes.Ldloc_0);//加载method类型变量
            if (!isvoid)//加载泛型类型数组变量
                il.Emit(OpCodes.Ldloc_S, 4);
            else
                il.Emit(OpCodes.Ldloc_3);
            il.Emit(OpCodes.Ldloc_1);//加载参数数组变量
            callmethod = typeof(Context).GetMethod("CallMethod", new Type[] { typeof(MethodBase),typeof(Type[]), typeof(object[]) });
            il.Emit(OpCodes.Call, callmethod);//把方法参数和相关信息扔到一个上下文方法处理
            if (!isvoid)
            {
                if (method.ReturnType.IsValueType || method.ReturnType.IsGenericType|| method.ReturnType.IsGenericParameter)
                {
                        //是值类型,泛型参,泛型拖进来脱衣服
                        il.Emit(OpCodes.Unbox_Any,GetType(method.ReturnType));
                   
                }
                else
                {
                    il.Emit(OpCodes.Castclass, method.ReturnType);
                }
                il.Emit(OpCodes.Stloc_2);

                il.Emit(OpCodes.Ldloc_2);
            }
            else
            {
                il.Emit(OpCodes.Pop);
            }
            il.Emit(OpCodes.Ret);
            
            
        }