使用传统的.net反射机制，调用类的方法时，在调用频率大的情况下，会感觉速度很慢。最近浏览卢彦的博客时，找到一个他改进后的反射调用类。试用以后感觉效率明显提高，特推荐给大家。作者重新实现了，反射调用方法，但是调用接口和.net原有方法一致。而且调用时抛出的异常为所调用类的实际异常，不像传统方式返回为包装异常。
文章来源：http://www.codeproject.com/csharp/FastMethodInvoker.asp
快速反射调用类
using System;using System.Collections.Generic;using System.Text;using System.Reflection;using System.Reflection.Emit;namespace FastMethodInvoker
{
class FastInvoke
{ public delegate object FastInvokeHandler(object target, object[] paramters); static object InvokeMethod(FastInvokeHandler invoke, object target, params object[] paramters) { return invoke(null, paramters);
} public static FastInvokeHandler GetMethodInvoker(MethodInfo methodInfo) { DynamicMethod dynamicMethod = new DynamicMethod(string.Empty, typeof(object), new Type[] { typeof(object), typeof(object[]) }, methodInfo.DeclaringType.Module); ILGenerator il = dynamicMethod.GetILGenerator(); ParameterInfo[] ps = methodInfo.GetParameters(); Type[] paramTypes = new Type[ps.Length]; for (int i = 0; i < paramTypes.Length; i++) { if (ps[i].ParameterType.IsByRef) paramTypes[i] = ps[i].ParameterType.GetElementType(); else paramTypes[i] = ps[i].ParameterType; } LocalBuilder[] locals = new LocalBuilder[paramTypes.Length]; for (int i = 0; i < paramTypes.Length; i++) { locals[i] = il.DeclareLocal(paramTypes[i], true); } for (int i = 0; i < paramTypes.Length; i++) { il.Emit(OpCodes.Ldarg_1); EmitFastInt(il, i); il.Emit(OpCodes.Ldelem_Ref); EmitCastToReference(il, paramTypes[i]); il.Emit(OpCodes.Stloc, locals[i]); } if (!methodInfo.IsStatic) { il.Emit(OpCodes.Ldarg_0); } for (int i = 0; i < paramTypes.Length; i++) { if (ps[i].ParameterType.IsByRef) il.Emit(OpCodes.Ldloca_S, locals[i]); else il.Emit(OpCodes.Ldloc, locals[i]); } if (methodInfo.IsStatic) il.EmitCall(OpCodes.Call, methodInfo, null); else il.EmitCall(OpCodes.Callvirt, methodInfo, null); if (methodInfo.ReturnType == typeof(void)) il.Emit(OpCodes.Ldnull); else EmitBoxIfNeeded(il, methodInfo.ReturnType); for (int i = 0; i < paramTypes.Length; i++) { if (ps[i].ParameterType.IsByRef) { il.Emit(OpCodes.Ldarg_1); EmitFastInt(il, i); il.Emit(OpCodes.Ldloc, locals[i]); if (locals[i].LocalType.IsValueType) il.Emit(OpCodes.Box, locals[i].LocalType); il.Emit(OpCodes.Stelem_Ref); } } il.Emit(OpCodes.Ret); FastInvokeHandler invoder = (FastInvokeHandler)dynamicMethod.CreateDelegate(typeof(FastInvokeHandler)); return invoder; } private static void EmitCastToReference(ILGenerator il, System.Type type) { if (type.IsValueType) { il.Emit(OpCodes.Unbox_Any, type); } else { il.Emit(OpCodes.Castclass, type); } } private static void EmitBoxIfNeeded(ILGenerator il, System.Type type) { if (type.IsValueType) { il.Emit(OpCodes.Box, type); } } private static void EmitFastInt(ILGenerator il, int value) { switch (value) { case -1: il.Emit(OpCodes.Ldc_I4_M1); return; case 0: il.Emit(OpCodes.Ldc_I4_0); return; case 1: il.Emit(OpCodes.Ldc_I4_1); return; case 2: il.Emit(OpCodes.Ldc_I4_2); return; case 3: il.Emit(OpCodes.Ldc_I4_3); return; case 4: il.Emit(OpCodes.Ldc_I4_4); return; case 5: il.Emit(OpCodes.Ldc_I4_5); return; case 6: il.Emit(OpCodes.Ldc_I4_6); return; case 7: il.Emit(OpCodes.Ldc_I4_7); return; case 8: il.Emit(OpCodes.Ldc_I4_8); return; } if (value > -129 && value < 128) { il.Emit(OpCodes.Ldc_I4_S, (SByte)value); } else { il.Emit(OpCodes.Ldc_I4, value); } } }
}
效果测试程序
using System;using System.Reflection;using System.Reflection.Emit;using System.Collections.Generic;using System.Text;using System.Diagnostics;namespace FastMethodInvoker{ class Program { static void Main(string[] args) { Type t = typeof(Person); MethodInfo methodInfo = t.GetMethod("Say"); Person person = new Person(); string word = "hello"; Person p = null; object[] param = new object[] { word, p, 3 }; int TestTimes = 100000; //测试次数，可自行调节看效果 传统方式反射#region 传统方式反射 try { Stopwatch watch = new Stopwatch(); watch.Start(); for (int i = 0; i < TestTimes; i++) { methodInfo.Invoke(person, param); } watch.Stop(); Console.WriteLine(TestTimes.ToString() + " times invoked by Reflection: " + watch.ElapsedMilliseconds + "ms"); } catch (System.Exception ex) { Console.WriteLine("传统方式反射 直接错误:" + ex.Message); Console.WriteLine("传统方式反射 内部错误:" + ex.InnerException.Message); } #endregion 快速反射#region 快速反射 try { Stopwatch watch1 = new Stopwatch(); FastInvoke.FastInvokeHandler fastInvoker = FastInvoke.GetMethodInvoker(methodInfo); watch1.Start(); for (int i = 0; i < TestTimes; i++) { fastInvoker(person, param); } watch1.Stop(); Console.WriteLine(TestTimes.ToString() + " times invoked by FastInvoke: " + watch1.ElapsedMilliseconds + "ms"); } catch (System.Exception ex) { Console.WriteLine("快速反射 错误:" + ex.Message); } #endregion 直接调用#region 直接调用 try { Stopwatch watch2 = new Stopwatch(); watch2.Start(); for (int i = 0; i < TestTimes; i++) { person.Say(ref word, out p, 3); } watch2.Stop(); Console.WriteLine(TestTimes.ToString() + " times invoked by DirectCall: " + watch2.ElapsedMilliseconds + "ms"); } catch (System.Exception ex) { Console.WriteLine("直接调用 错误:" + ex.Message); } #endregion Console.ReadLine(); } } public class Person { public void Say(ref string word, out Person p, int avi) { word = "ttt" + avi.ToString(); p = new Person(); //throw new System.Exception("出错了哦"); } }}
