Call the method by using the number of expressions and the number of expressions

Call the method by using the number of expressions and the number of expressions

Using the expression tree to build a delegate to improve reflection performance makes a small change, which is suitable for your use.

    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();        }     }

Test:

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) =>$ "name: {name}, Date of Birth: {DateTime. now-_ birthDay}, Gender: {(sex = 1? "Male": "female")} ";} class Program {static void Main (string [] args) {Type targetType = Assembly. getExecutingAssembly (). getType ("leleapplication1.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), "Sugar Pier", 1);} static void WithOutConstructor (MethodInfo methodInfo) {var func = (Func <string, int, string>) DynamicMethodBuilder. buildDynamicDelegate (methodInfo); Console. writeLine (func ("Sugar Pier", 1 ));}}