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);
}
}
}
}
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
快速反射
直接调用
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");
}
}
}
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