C#各种反射动态赋值取值方法

using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Web;
 using System.Web.UI;
 using System.Web.UI.WebControls;
 using System.Data;
using KaiCommon;
using System.Reflection;
using KaiCommon.ORM;
using System.Linq.Expressions;
using System.Reflection.Emit;

public delegate void PropertySetter<T>(T value);
public delegate T PropertyGetter<T>();

public partial class Tools_TestGrid : System.Web.UI.Page
{
#region 泛型委托实现
public PropertyGetter<int> PropGet;
public PropertySetter<int> PropSet;
public void BuildSetMethod(TestData td)
{
Type t = td.GetType();
PropertyInfo pi = t.GetProperty("Name");
MethodInfo setter = pi.GetSetMethod();

PropSet = (PropertySetter<int>)Delegate.CreateDelegate(typeof(PropertySetter<int>), td, setter);

//string value = strPropGetter();
}

public void BuildGetMethod(TestData td)
{
Type t = td.GetType();
PropertyInfo pi = t.GetProperty("Name");
MethodInfo getter = pi.GetGetMethod();

PropGet = (PropertyGetter<int>)Delegate.CreateDelegate(typeof(PropertyGetter<int>), td, getter);

//string value = strPropGetter();
}

#endregion

#region 表达式树实现
Func<object, int> LmdGetProp; //Func<TestData, int>
public void LmdGet(Type entityType, string propName)
{
#region 通过方法取值
var p = entityType.GetProperty(propName);
//对象实例
var param_obj = Expression.Parameter(typeof(object), "obj");
//值
//var param_val = Expression.Parameter(typeof(object), "val");
//转换参数为真实类型
var body_obj = Expression.Convert(param_obj, entityType);

//调用获取属性的方法
var body = Expression.Call(body_obj, p.GetGetMethod());
LmdGetProp = Expression.Lambda<Func<object, int>>(body, param_obj).Compile();
#endregion

#region 表达式取值 
//var p = entityType.GetProperty(propName);
////lambda的参数u
//var param_u = Expression.Parameter(entityType, "u");
////lambda的方法体 u.Age
//var pGetter = Expression.Property(param_u, p);
////编译lambda
//LmdGetProp = Expression.Lambda<Func<TestData, int>>(pGetter, param_u).Compile();
#endregion
}
Action<object, object> LmdSetProp;
public void LmdSet(Type entityType, string propName)
{
var p = entityType.GetProperty(propName);
//对象实例
var param_obj = Expression.Parameter(typeof(object), "obj");
//值
var param_val = Expression.Parameter(typeof(object), "val");
//转换参数为真实类型
var body_obj = Expression.Convert(param_obj, entityType);
var body_val = Expression.Convert(param_val, p.PropertyType);
//调用给属性赋值的方法
var body = Expression.Call(body_obj, p.GetSetMethod(), body_val);
LmdSetProp = Expression.Lambda<Action<object, object>>(body, param_obj, param_val).Compile();

}
#endregion


#region Emit动态方法实现
public delegate void SetValueDelegateHandler(TestData entity, object value);
public SetValueDelegateHandler EmitSetValue;
public void BuildEmitMethod(Type entityType, string propertyName)
{
//Type entityType = entity.GetType();
Type parmType = typeof(object);
// 指定函数名
string methodName = "set_" + propertyName;
// 搜索函数，不区分大小写 IgnoreCase
var callMethod = entityType.GetMethod(methodName, BindingFlags.Instance | BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.NonPublic);
// 获取参数
var para = callMethod.GetParameters()[0];
// 创建动态函数
DynamicMethod method = new DynamicMethod("EmitCallable", null, new Type[] { entityType, parmType }, entityType.Module);
// 获取动态函数的 IL 生成器
var il = method.GetILGenerator();
// 创建一个本地变量，主要用于 Object Type to Propety Type
var local = il.DeclareLocal(para.ParameterType, true);
// 加载第 2 个参数【(T owner, object value)】的 value
il.Emit(OpCodes.Ldarg_1);
if (para.ParameterType.IsValueType)
{
il.Emit(OpCodes.Unbox_Any, para.ParameterType);// 如果是值类型，拆箱 string = (string)object;
}
else
{
il.Emit(OpCodes.Castclass, para.ParameterType);// 如果是引用类型，转换 Class = object as Class
}
il.Emit(OpCodes.Stloc, local);// 将上面的拆箱或转换，赋值到本地变量，现在这个本地变量是一个与目标函数相同数据类型的字段了。
il.Emit(OpCodes.Ldarg_0); // 加载第一个参数 owner
il.Emit(OpCodes.Ldloc, local);// 加载本地参数
il.EmitCall(OpCodes.Callvirt, callMethod, null);//调用函数
il.Emit(OpCodes.Ret); // 返回
/* 生成的动态函数类似：
* void EmitCallable(T owner, object value)
* {
* T local = (T)value;
* owner.Method(local);
* }
*/

EmitSetValue = method.CreateDelegate(typeof(SetValueDelegateHandler)) as SetValueDelegateHandler;

}
#endregion 

protected void Page_Load(object sender, EventArgs e)
{

this.Response.Write("当前framework版本：" + Environment.Version.Major + "<br/>");
int max = 1000000;
this.Response.Write("循环次数：" + max + "<br/>");
if (!IsPostBack)
{
//基本方法
DateTime time = DateTime.Now;
TestData d = new TestData();
for (int i = 0; i < max; i++)
{
d.Name = i;
}
TimeSpan ts = DateTime.Now - time;
this.Response.Write("基本方法:" + ts.TotalMilliseconds + "<br/>");

//反射方法
Type type = d.GetType();
PropertyInfo pi = type.GetProperty("Name");
time = DateTime.Now;
for (int i = 0; i < max; i++)
{
pi.SetValue(d, i, null);
}
ts = DateTime.Now - time;
this.Response.Write("反射方法:" + ts.TotalMilliseconds + "<br/>");

//dynamic动态类型方法
dynamic dobj = Activator.CreateInstance<TestData>();
time = DateTime.Now;
for (int i = 0; i < max; i++)
{
dobj.Name = i;
}
ts = DateTime.Now - time;
this.Response.Write("dynamic动态类型方法:" + ts.TotalMilliseconds + "<br/>");

//泛型委托赋值方法
d.Name = -1;
BuildSetMethod(d);
time = DateTime.Now;
for (int i = 0; i < max; i++)
{
this.PropSet(i);
}
ts = DateTime.Now - time;
this.Response.Write("泛型委托赋值方法:" + ts.TotalMilliseconds + "<br/>");
this.Response.Write("v:" + d.Name + "<br/>");

//泛型委托取值方法
d.Name = -1;
BuildGetMethod(d);
time = DateTime.Now;
for (int i = 0; i < max; i++)
{
this.PropGet();
}
ts = DateTime.Now - time;
this.Response.Write("泛型委托取值方法:" + ts.TotalMilliseconds + "<br/>");
this.Response.Write("v:" + d.Name + "<br/>");

//表达式树赋值方法
d.Name = -1;
LmdSet(typeof(TestData), "Name");
time = DateTime.Now;
for (int i = 0; i < max; i++)
{
this.LmdSetProp(d, i);
}
ts = DateTime.Now - time;
this.Response.Write("表达式树赋值方法:" + ts.TotalMilliseconds + "<br/>");
this.Response.Write("v:" + d.Name + "<br/>");

//表达式树取值方法
d.Name = -132;
this.LmdGet(typeof(TestData), "Name");
time = DateTime.Now;
for (int i = 0; i < max; i++)
{
this.LmdGetProp(d);
}
ts = DateTime.Now - time;
this.Response.Write("表达式树取值方法:" + ts.TotalMilliseconds + "<br/>");
this.Response.Write("v:" + this.LmdGetProp(d) + "<br/>");

//EMIT动态方法赋值
d.Name = -1;
this.BuildEmitMethod(d.GetType(), "Name");
time = DateTime.Now;
for (int i = 0; i < max; i++)
{
this.EmitSetValue(d, i);
}
ts = DateTime.Now - time;
this.Response.Write("EMIT动态方法:" + ts.TotalMilliseconds + "<br/>");
this.Response.Write("v:" + d.Name + "<br/>");

//TestDataBind();
}
}

}

public class TestData
{
public int Name { get; set; }
}