本文共 8282 字，大约阅读时间需要 27 分钟。
先上测试代码
using System.Text;namespace Model{ public partial class Class1 { public Class1() { } private string _s = ""; private int _i = 0; private decimal _d = 0; private StringBuilder _sb = new StringBuilder(); public string S { set { _s = value; } get { return _s; } } public int I { set { _i = value; } get { return _i; } } public decimal D { set { _d = value; } get { return _d; } } public StringBuilder SB { set { _sb = value; } get { return _sb; } } public int func() { int s = 0; for (int i = 0; i < 1000; i++) { s = s + i; } return s; } }}///using System;using System.Collections.Generic;using System.Linq;using System.Text;using Model;using System.Reflection;using System.Diagnostics;namespace testReflect{ class Program { static void Main(string[] args) { const int count = 100000; Console.WriteLine("count="+count); Stopwatch sw = new Stopwatch(); StringBuilder test = new StringBuilder(); sw.Restart(); for (int i = 0; i < count; i++) { Class1 m = new Class1(); m.D = 100; m.I = 200; m.S = "string"; m.SB = new StringBuilder("StringBuilder"); test.Append(m.D); test.Append(m.I); test.Append(m.S); test.Append(m.SB); } sw.Stop(); Console.WriteLine("直接创建,赋值并访问内存中对象属性： " + sw.ElapsedTicks); //Console.WriteLine("直接创建,赋值并访问内存中对象属性： " + sw.ElapsedTicks); long basic = sw.ElapsedTicks; sw.Restart(); test = new StringBuilder(); for (int i = 0; i < count; i++) { var t = typeof(Class1); ConstructorInfo ct = t.GetConstructor(new Type[] { }); var m = ct.Invoke(null); PropertyInfo pd = t.GetProperty("D"); pd.SetValue(m, 100m, null); PropertyInfo pi = t.GetProperty("I"); pi.SetValue(m, 200, null); PropertyInfo ps = t.GetProperty("S"); ps.SetValue(m, "string", null); PropertyInfo psb = t.GetProperty("StringBuilder"); PropertyInfo[] props = m.GetType().GetProperties(); foreach (var p in props) { test.Append(p.GetValue(m, null)); } } sw.Stop(); Console.WriteLine("反射创建，赋值并访问内存中对象属性： " + sw.ElapsedTicks + "(" + sw.ElapsedTicks / basic + ")"); test = new StringBuilder(); sw.Restart(); for (int i = 0; i < count; i++) { dynamic dm = new Class1(); dm.D = 100; dm.I = 200; dm.S = "string"; dm.SB = new StringBuilder("StringBuilder"); test.Append(dm.D); test.Append(dm.I); test.Append(dm.S); test.Append(dm.SB); } sw.Stop(); Console.WriteLine("dynamic直接创建，赋值并访问内存中对象属性：" + sw.ElapsedTicks + "(" + sw.ElapsedTicks / basic + ")"); test = new StringBuilder(); sw.Restart(); for (int i = 0; i < count; i++) { var t = typeof(Class1); ConstructorInfo ct = t.GetConstructor(new Type[] { }); dynamic dm = ct.Invoke(null); dm.D = 100; dm.I = 200; dm.S = "string"; dm.SB = new StringBuilder("StringBuilder"); test.Append(dm.D); test.Append(dm.I); test.Append(dm.S); test.Append(dm.SB); } sw.Stop(); Console.WriteLine("dynamic反射创建，赋值并访问内存中对象属性：" + sw.ElapsedTicks + "(" + sw.ElapsedTicks / basic + ")"); test = new StringBuilder(); sw.Restart(); for (int i = 0; i < count; i++) { Class1 m = new Class1(); test.Append(m.func()); } sw.Stop(); Console.WriteLine("直接调用内存中对象方法： " + sw.ElapsedTicks + "(" + sw.ElapsedTicks / basic + ")"); sw.Restart(); test = new StringBuilder(); for (int i = 0; i < count; i++) { var t = typeof(Class1); MethodInfo meth = t.GetMethod("func"); ConstructorInfo ct = t.GetConstructor(new Type[] { }); test.Append(meth.Invoke(ct.Invoke(null), null)); } sw.Stop(); Console.WriteLine("反射调用内存中对象方法： " + sw.ElapsedTicks + "(" + sw.ElapsedTicks / basic + ")"); test = new StringBuilder(); sw.Restart(); for (int i = 0; i < count; i++) { dynamic dm = new Class1(); test.Append(dm.func()); } sw.Stop(); Console.WriteLine("dynamic直接调用内存中对象方法：" + sw.ElapsedTicks + "(" + sw.ElapsedTicks / basic + ")"); test = new StringBuilder(); sw.Restart(); for (int i = 0; i < count; i++) { var t = typeof(Class1); ConstructorInfo ct = t.GetConstructor(new Type[] { }); dynamic dm = ct.Invoke(null); test.Append(dm.func()); } sw.Stop(); Console.WriteLine("dynamic反射调用内存中对象方法：" + sw.ElapsedTicks + "(" + sw.ElapsedTicks / basic + ")"); Console.WriteLine("###############################"); sw.Restart(); test = new StringBuilder(); for (int i = 0; i < count; i++) { Assembly a = Assembly.LoadFile(AppDomain.CurrentDomain.BaseDirectory + @"\Model.dll"); var t = a.GetType("Model.Class1"); ConstructorInfo ct = t.GetConstructor(new Type[] { }); var rm = ct.Invoke(null); PropertyInfo pd = t.GetProperty("D"); pd.SetValue(rm, 100m, null); PropertyInfo pi = t.GetProperty("I"); pi.SetValue(rm, 200, null); PropertyInfo ps = t.GetProperty("S"); ps.SetValue(rm, "string", null); PropertyInfo psb = t.GetProperty("SB"); psb.SetValue(rm, new StringBuilder("StringBuilder"), null); PropertyInfo[] props = t.GetProperties(); foreach (var p in props) { test.Append(p.GetValue(rm, null)); } } sw.Stop(); Console.WriteLine("使用反射加载程序集，创建，赋值，访问，对象属性： " + sw.ElapsedTicks + "(" + sw.ElapsedTicks / basic + ")"); sw.Restart(); test = new StringBuilder(); for (int i = 0; i < count; i++) { Assembly a = Assembly.LoadFile(AppDomain.CurrentDomain.BaseDirectory + @"\Model.dll"); var t = a.GetType("Model.Class1"); ConstructorInfo ct = t.GetConstructor(new Type[] { }); dynamic dm = ct.Invoke(null); dm.D = 100m; dm.I = 200; dm.S = "string"; dm.SB = new StringBuilder("StringBuilder"); test.Append(dm.D); test.Append(dm.I); test.Append(dm.S); test.Append(dm.SB); } sw.Stop(); Console.WriteLine("dynamic赋值，使用反射加载程序集，创建，赋值，访问，对象属性： " + sw.ElapsedTicks + "(" + sw.ElapsedTicks / basic + ")"); } }} 分别循环1000,10000,50000,100000次
所得到的数据显示，直接创建赋值是快速的方法。
反射创建所需要的时间比依次是9x,15x,15x,15x
对于两种dynamic，
所需的时间比依次是36,8,3,2和7,4,3,3。说明了在反复调用次数少的情况下，dynamic方式并不优于反射，但是在反复调用次数多的情况下，使用dynamic方式优于直接使用反射。两种dynamic方式在调用次数多的情况下，差距也不是很多
对于方法的调用，发现，时间比都差不多。反射稍慢一点。dynamic方式略占优势。
对于加载assembly的方式，绝对是最慢的，通常要在100-150倍左右。
此处我想强调的是，虽然速度差别很大，但是通常的代码运行很少有循环1000次10000次的。即便有，其绝对值还是很小的。相对网络延迟开销，反射所花去的开销可以忽略不计。因此，因为性能问题拒绝反射是愚蠢的。使用dynamic类型，相对反射来说，代码可以写的更优雅。
以上数据，仅供参考。
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