Summarize instance code called with an expression number

Using expression tree to construct delegates to improve reflection performance make a little change just for your own use

    public static class Dynamicmethodbuilder {public static Delegate builddynamicdelegate (MethodInfo MethodInfo, Constr            Uctorinfo 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, paramexpr                Essions); }}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}, days of birth: {datetime.now-_birthday}, Gender: {(Sex = = 1?    "Male": "Female")} "; } class Program {static void Main (string[] args) {Type TargetType = assembly.getexecuting Assembly ().            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), "Sugar Pier", 1)); } static void Withoutconstructor (MethodInfo MethodInfo) {var func = (func<string, int, string            >) dynamicmethodbuilder.builddynamicdelegate (methodInfo);        Console.WriteLine (func ("Sugar Pier", 1)); }    }