韦德国际1946手机版:选择表明式数调用方法,反

作者: 韦德国际1946手机版  发布:2019-08-20

韦德国际1946手机版:选择表明式数调用方法,反射调用与Lambda表明式调用。动用表明式数调用方法,表明式数调用

照着 利用表明式树创设委托改进反射品质 做了好几小更校正好契合自个儿用

    public static class DynamicMethodBuilder
    {
        public static Delegate BuildDynamicDelegate(MethodInfo methodInfo, ConstructorInfo constructorInfo = null)
        {
            if (methodInfo == null)
                throw new ArgumentNullException("methodInfo");
            List<ParameterExpression> paramExpressions = methodInfo.GetParameters().Select((p, i) =>
            {
                var name = "param"   (i   1);
                return Expression.Parameter(p.ParameterType, name);
            }).ToList();
            MethodCallExpression callExpression;
            if (methodInfo.IsStatic)
            {
                //Call(params....)
                callExpression = Expression.Call(methodInfo, paramExpressions);
            }
            else
            {
                if (constructorInfo != null)
                {
                    //Instance(params).Call(params....)
                    List<ParameterExpression> constructorParamExpressions = constructorInfo.GetParameters().Select((p, i) =>
                    {
                        var name = "constparam"   (i   1);
                        return Expression.Parameter(p.ParameterType, name);
                    }).ToList();
                    callExpression = Expression.Call(Expression.New(constructorInfo, constructorParamExpressions), methodInfo, paramExpressions);
                    paramExpressions.InsertRange(0, constructorParamExpressions);
                }
                else
                {
                    callExpression = Expression.Call(Expression.New(methodInfo.ReflectedType), methodInfo, paramExpressions);
                }
            }
            return Expression.Lambda(callExpression, paramExpressions).Compile();
        } 
    }

测试:

    public class Baby
    {
        private readonly DateTime _birthDay;
        public Baby(DateTime birthDay)
        {
            _birthDay = birthDay;
        }
        public Baby()
        {
            _birthDay = DateTime.Now;
        }

        public string GetBabyInfo(string name, int sex) => $"姓名:{name} , 出生天数:{ DateTime.Now- _birthDay} ,性别 :{(sex == 1 ? "男" : "女")}";

    }

    class Program
    {
        static void Main(string[] args)
        {
            Type targetType = Assembly.GetExecutingAssembly().GetType("ConsoleApplication1.Baby");

            MethodInfo methodInfo = targetType.GetMethod("GetBabyInfo", new[] { typeof(string), typeof(int) });
            ConstructorInfo constructor = targetType.GetConstructor(new[] { typeof(DateTime) });

            WithConstructor(methodInfo, constructor);
            WithOutConstructor(methodInfo);
            Console.ReadKey();
        }
        static void WithConstructor(MethodInfo methodInfo, ConstructorInfo constructor)
        {
            var func = (Func<DateTime, string, int, string>)DynamicMethodBuilder.BuildDynamicDelegate(methodInfo, constructor);
            Console.WriteLine(func(DateTime.Now.AddDays(-100), "糖墩儿", 1));
        }
        static void WithOutConstructor(MethodInfo methodInfo)
        {
            var func = (Func<string, int, string>)DynamicMethodBuilder.BuildDynamicDelegate(methodInfo);
            Console.WriteLine(func("糖墩儿", 1));
        }
    }

  

 

照着利用表明式树构基本建设委员会托改良反射品质做了一点小更勘误好适合自身用 public static class DynamicMeth...

照着 利用表明式树营造委托改革反射品质 做了少数小改变优异契合自身用

照着 选取表明式树构建委会托革新反射质量 做了几许小更考订好契合自个儿用

    public static class DynamicMethodBuilder
    {
        public static Delegate BuildDynamicDelegate(MethodInfo methodInfo, ConstructorInfo constructorInfo = null)
        {
            if (methodInfo == null)
                throw new ArgumentNullException("methodInfo");
            List<ParameterExpression> paramExpressions = methodInfo.GetParameters().Select((p, i) =>
            {
                var name = "param"   (i   1);
                return Expression.Parameter(p.ParameterType, name);
            }).ToList();
            MethodCallExpression callExpression;
            if (methodInfo.IsStatic)
            {
                //Call(params....)
                callExpression = Expression.Call(methodInfo, paramExpressions);
            }
            else
            {
                if (constructorInfo != null)
                {
                    //Instance(params).Call(params....)
                    List<ParameterExpression> constructorParamExpressions = constructorInfo.GetParameters().Select((p, i) =>
                    {
                        var name = "constparam"   (i   1);
                        return Expression.Parameter(p.ParameterType, name);
                    }).ToList();
                    callExpression = Expression.Call(Expression.New(constructorInfo, constructorParamExpressions), methodInfo, paramExpressions);
                    paramExpressions.InsertRange(0, constructorParamExpressions);
                }
                else
                {
                    callExpression = Expression.Call(Expression.New(methodInfo.ReflectedType), methodInfo, paramExpressions);
                }
            }
            return Expression.Lambda(callExpression, paramExpressions).Compile();
        } 
    }
    public static class DynamicMethodBuilder
    {
        public static Delegate BuildDynamicDelegate(MethodInfo methodInfo, ConstructorInfo constructorInfo = null)
        {
            if (methodInfo == null)
                throw new ArgumentNullException("methodInfo");
            List<ParameterExpression> paramExpressions = methodInfo.GetParameters().Select((p, i) =>
            {
                var name = "param"   (i   1);
                return Expression.Parameter(p.ParameterType, name);
            }).ToList();
            MethodCallExpression callExpression;
            if (methodInfo.IsStatic)
            {
                //Call(params....)
                callExpression = Expression.Call(methodInfo, paramExpressions);
            }
            else
            {
                if (constructorInfo != null)
                {
                    //Instance(params).Call(params....)
                    List<ParameterExpression> constructorParamExpressions = constructorInfo.GetParameters().Select((p, i) =>
                    {
                        var name = "constparam"   (i   1);
                        return Expression.Parameter(p.ParameterType, name);
                    }).ToList();
                    callExpression = Expression.Call(Expression.New(constructorInfo, constructorParamExpressions), methodInfo, paramExpressions);
                    paramExpressions.InsertRange(0, constructorParamExpressions);
                }
                else
                {
                    callExpression = Expression.Call(Expression.New(methodInfo.ReflectedType), methodInfo, paramExpressions);
                }
            }
            return Expression.Lambda(callExpression, paramExpressions).Compile();
        } 
    }

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关键词: 表达式树 反射 C#Effective高

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