Expression基础体验
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Linq.Expressions;
using System.Text;
using System.Threading.Tasks; namespace Unit
{
class T
{
public void Test()
{
Console.WriteLine("Test Class!");
}
}
class S
{
private List<int> ids = new List<int>();
public string Name { set; get; } public List<int> Ids { set { ids = value; } get { return ids; } }
}
class ET
{
public void Run()
{
//add
Add(, );//+
AddAssign(, );
Subtract(, );//-
SubtractAssign(,);
Multiply(,);
MultiplyAssign(,);
Divide(, );
DivideAssign(,);
Decrement();//i--;
Increment();//++
Modulo(); And(true, false); //&
AndAlso(true, false); //&&
Or(true, false);
OrElse(true, false); //||
LessThan(, );
Coalesce(, );
Coalesce(null, );
Is();
If();
IfElse();
Condition();
Switch();
Loop();
TypeAs();
Convert();
New();
NewArray();
NewArrayBounds();
ListInit();
ListBind();
}
/// <summary>
/// +
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
private void Add(int a,int b)
{
var left = Expression.Parameter(typeof(int));
var right = Expression.Parameter(typeof(int));
Expression exp = Expression.Add(left, right);
Expression<Func<int, int, int>> lambda = Expression.Lambda<Func<int, int, int>>(exp, new ParameterExpression[] { left, right });
var l = lambda.Compile();
var r = l(a, b);
Console.WriteLine(r);
} public static int Add2(int a,int b)
{
return ;
} /// <summary>
/// 利用方法+
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
private void AddAssign(int a, int b)
{
var left = Expression.Parameter(typeof(int));
var right = Expression.Parameter(typeof(int));
Expression exp = Expression.AddAssign(left, right, this.GetType().GetMethod("Add2"));
Expression<Func<int, int, int>> lambda = Expression.Lambda<Func<int, int, int>>(exp, new ParameterExpression[] { left, right });
var l = lambda.Compile();
var r = l(a, b);
Console.WriteLine(r);
}
/// <summary>
/// &
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
private void And(bool a, bool b)
{
var left = Expression.Parameter(typeof(bool));
var right = Expression.Parameter(typeof(bool));
Expression exp = Expression.And(left, right);
Expression<Func<bool, bool, bool>> lambda = Expression.Lambda<Func<bool, bool, bool>>(exp, new ParameterExpression[] { left, right });
var l = lambda.Compile();
var r = l(a, b);
Console.WriteLine(r);
}
/// <summary>
/// &&
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
private void AndAlso(bool a, bool b)
{
var left = Expression.Parameter(typeof(bool));
var right = Expression.Parameter(typeof(bool));
Expression exp = Expression.AndAlso(left, right);
Expression<Func<bool, bool, bool>> lambda = Expression.Lambda<Func<bool, bool, bool>>(exp, new ParameterExpression[] { left, right });
var l = lambda.Compile();
var r = l(a, b);
Console.WriteLine(r);
}
/// <summary>
/// |
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
private void Or(bool a, bool b)
{
var left = Expression.Parameter(typeof(bool));
var right = Expression.Parameter(typeof(bool));
Expression exp = Expression.Or(left, right);
Expression<Func<bool, bool, bool>> lambda = Expression.Lambda<Func<bool, bool, bool>>(exp, new ParameterExpression[] { left, right });
var l = lambda.Compile();
var r = l(a, b);
Console.WriteLine(r);
}
/// <summary>
/// ||
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
private void OrElse(bool a, bool b)
{
var left = Expression.Parameter(typeof(bool));
var right = Expression.Parameter(typeof(bool));
Expression exp = Expression.OrElse(left, right);
Expression<Func<bool, bool, bool>> lambda = Expression.Lambda<Func<bool, bool, bool>>(exp, new ParameterExpression[] { left, right });
var l = lambda.Compile();
var r = l(a, b);
Console.WriteLine(r);
} /// <summary>
/// -
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
private void Subtract(int a, int b)
{
var left = Expression.Parameter(typeof(int));
var right = Expression.Parameter(typeof(int));
Expression exp = Expression.Subtract(left, right);
Expression<Func<int, int, int>> lambda = Expression.Lambda<Func<int, int, int>>(exp, new ParameterExpression[] { left, right });
var l = lambda.Compile();
var r = l(a, b);
Console.WriteLine(r);
}
private void SubtractAssign(int a, int b)
{
var left = Expression.Parameter(typeof(int));
var right = Expression.Parameter(typeof(int));
Expression exp = Expression.SubtractAssign(left, right, this.GetType().GetMethod("Add2"));
Expression<Func<int, int, int>> lambda = Expression.Lambda<Func<int, int, int>>(exp, new ParameterExpression[] { left, right });
var l = lambda.Compile();
var r = l(a, b);
Console.WriteLine(r);
} /// <summary>
/// *
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
private void Multiply(int a, int b)
{
var left = Expression.Parameter(typeof(int));
var right = Expression.Parameter(typeof(int));
Expression exp = Expression.Multiply(left, right);
Expression<Func<int, int, int>> lambda = Expression.Lambda<Func<int, int, int>>(exp, new ParameterExpression[] { left, right });
var l = lambda.Compile();
var r = l(a, b);
Console.WriteLine(r);
}
private void MultiplyAssign(int a, int b)
{
var left = Expression.Parameter(typeof(int));
var right = Expression.Parameter(typeof(int));
Expression exp = Expression.MultiplyAssign(left, right, this.GetType().GetMethod("Add2"));
Expression<Func<int, int, int>> lambda = Expression.Lambda<Func<int, int, int>>(exp, new ParameterExpression[] { left, right });
var l = lambda.Compile();
var r = l(a, b);
Console.WriteLine(r);
}
/// <summary>
/// /
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
private void Divide(int a, int b)
{
var left = Expression.Parameter(typeof(int));
var right = Expression.Parameter(typeof(int));
Expression exp = Expression.Divide(left, right);
Expression<Func<int, int, int>> lambda = Expression.Lambda<Func<int, int, int>>(exp, new ParameterExpression[] { left, right });
var l = lambda.Compile();
var r = l(a, b);
Console.WriteLine(r);
}
/// <summary>
/// a/=b
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
private void DivideAssign(int a, int b)
{
var left = Expression.Parameter(typeof(int));
var right = Expression.Parameter(typeof(int));
Expression exp = Expression.DivideAssign(left, right, this.GetType().GetMethod("Add2"));
Expression<Func<int, int, int>> lambda = Expression.Lambda<Func<int, int, int>>(exp, new ParameterExpression[] { left, right });
var l = lambda.Compile();
var r = l(a, b);
Console.WriteLine(r);
}
/// <summary>
/// --
/// </summary>
/// <param name="a"></param>
private void Decrement(int a)
{
var left = Expression.Parameter(typeof(int));
Expression exp = Expression.Decrement(left);
Expression<Func<int, int>> lambda = Expression.Lambda<Func<int, int>>(exp, new ParameterExpression[] { left });
var l = lambda.Compile();
var r = l(a);
Console.WriteLine(r);
}
/// <summary>
/// ++
/// </summary>
/// <param name="a"></param>
private void Increment(int a)
{
var left = Expression.Parameter(typeof(int));
Expression exp = Expression.Increment(left);
Expression<Func<int, int>> lambda = Expression.Lambda<Func<int, int>>(exp, new ParameterExpression[] { left });
var l = lambda.Compile();
var r = l(a);
Console.WriteLine(r);
}
/// <summary>
/// >
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
private void LessThan(int a, int b)
{
var left = Expression.Parameter(typeof(int));
var right = Expression.Parameter(typeof(int));
Expression exp = Expression.LessThan(left, right);
Expression<Func<int, int, bool>> lambda = Expression.Lambda<Func<int, int, bool>>(exp, new ParameterExpression[] { left, right });
var l = lambda.Compile();
var r = l(a,b);
Console.WriteLine(r);
}
/// <summary>
/// ??
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
private void Coalesce(int? a, int b)
{
var left = Expression.Parameter(typeof(int?));
var right = Expression.Parameter(typeof(int)); var right2 = Expression.Assign(right, Expression.Default(typeof(int)));
Expression exp = Expression.Coalesce(left, right2);
Expression<Func<int?, int, int>> lambda = Expression.Lambda<Func<int?, int, int>>(exp, new ParameterExpression[] { left, right });
var l = lambda.Compile();
var r = l(a, b);
Console.WriteLine(r);
} public static bool IsFalse(bool flag){
return false;
}
/// <summary>
/// is
/// </summary>
private void Is()
{
var v1 = Expression.Parameter(typeof(bool)); var v11 = Expression.Assign(v1,Expression.Constant(true));
var v2 = Expression.IsFalse(v1, this.GetType().GetMethod("IsFalse"));
Expression exp = Expression.IsFalse(v2);
var v3=Expression.TypeIs(Expression.Constant(new List<int>()),typeof(IList<int>));
Expression<Func<bool,bool>> lambda = Expression.Lambda<Func<bool,bool>>(exp, new ParameterExpression[] {v1 });
var l = lambda.Compile();
var r = l(true);
Console.WriteLine(r);
Expression<Func<bool>> lambda2 = Expression.Lambda<Func<bool>>(v3);
var l2 = lambda2.Compile();
Console.WriteLine(l2());
}
/// <summary>
/// if
/// </summary>
private void If()
{
var v1 = Expression.Variable(typeof(int),"a");
var v11 = Expression.Assign(v1, Expression.Constant());
var v2 = Expression.GreaterThan(v11, Expression.Constant());
Expression exp = Expression.IfThen(v2,Expression.Call(typeof(Console).GetMethod("WriteLine",new Type[]{typeof(int)}),v1));
Expression exp2 = Expression.Block(new[]{v1},exp);
Expression<Action> lambda = Expression.Lambda<Action>(exp2, new ParameterExpression[] { });
var l = lambda.Compile();
l();
} /// <summary>
/// if else
/// </summary>
private void IfElse()
{
var v1 = Expression.Variable(typeof(int), "a");
var v11 = Expression.Assign(v1, Expression.Constant());
var v2 = Expression.GreaterThan(v11, Expression.Constant());
Expression exp = Expression.IfThenElse(v2, Expression.Call(typeof(Console).GetMethod("WriteLine", new Type[] { typeof(string) }), Expression.Constant("True")), Expression.Call(typeof(Console).GetMethod("WriteLine", new Type[] { typeof(string) }), Expression.Constant("False")));
Expression exp2 = Expression.Block(new[] { v1 }, exp);
Expression<Action> lambda = Expression.Lambda<Action>(exp2, new ParameterExpression[] { });
var l = lambda.Compile();
l();
} /// <summary>
/// trueTest?ifTrue:ifFalse;
/// </summary>
private void Condition()
{
var v1 = Expression.Variable(typeof(int), "a");
var v11 = Expression.Assign(v1, Expression.Constant());
var v2 = Expression.GreaterThan(v1, Expression.Constant());
Expression exp = Expression.Condition(v2, Expression.Call(typeof(Console).GetMethod("WriteLine", new Type[] { typeof(string) }), Expression.Constant("True")), Expression.Call(typeof(Console).GetMethod("WriteLine", new Type[] { typeof(string) }), Expression.Constant("False")));
Expression exp2 = Expression.Block(new[] { v1 },v11, exp);
Expression<Action> lambda = Expression.Lambda<Action>(exp2, new ParameterExpression[] { });
var l = lambda.Compile();
l();
}
/// <summary>
/// switch
/// </summary>
/// <param name="i"></param>
private void Switch(int i)
{
var par = Expression.Parameter(typeof(int));
var target = Expression.Label(typeof(int),"a");
var exp = Expression.Switch(par, Expression.Break(target, Expression.Constant(-)), Expression.SwitchCase(Expression.Break(target, par), Expression.Constant()));
var lbl = Expression.Label(target, Expression.Constant());
var block = Expression.Block(exp,lbl);
Expression<Func<int, int>> lambda = Expression.Lambda<Func<int, int>>(block, new ParameterExpression[] { par });
var l = lambda.Compile();
Console.WriteLine(l(i));
}
/// <summary>
/// while(true){}
/// </summary>
/// <param name="i"></param>
private void Loop(int i)
{
var par = Expression.Parameter(typeof(int));
var ret = Expression.Variable(typeof(int), "ret");
var v11 = Expression.Assign(ret, Expression.Constant());
var lbl = Expression.Label(typeof(int));
var lbl2 = Expression.Label(lbl,Expression.Constant());
var block1 = Expression.Block(Expression.AddAssign(ret,par),Expression.SubtractAssign(par,Expression.Constant()));
var condition = Expression.IfThenElse(Expression.GreaterThan(par, Expression.Constant()),block1, Expression.Break(lbl, ret));
var block2 = Expression.Block(new[] { ret }, v11, Expression.Loop(condition), lbl2);// Expression.Block(new[] { ret }, v11, Expression.Loop(condition,lbl)) 可以达到一样的效果
Expression<Func<int, int>> lambda = Expression.Lambda<Func<int, int>>(block2, new ParameterExpression[] { par });
var l = lambda.Compile();
Console.WriteLine(l(i));
} /// <summary>
/// as
/// </summary>
private void TypeAs()
{
Expression s = Expression.Constant();
var t=Expression.TypeAs(s, typeof(object));
var call = Expression.Call(typeof(Console).GetMethod("WriteLine", new[] { typeof(int) }), Expression.Unbox(t, typeof(int)));
Expression<Action> lambda = Expression.Lambda<Action>(call);
var l=lambda.Compile();
l();
} /// <summary>
/// 强转 class定义TypeConverter,TypeConverterAttribute
/// </summary>
private void Convert()
{
Expression s = Expression.Constant(7.5);
var t = Expression.Convert(s, typeof(int));
var call = Expression.Call(typeof(Console).GetMethod("WriteLine", new[] { typeof(int) }),t);
Expression<Action> lambda = Expression.Lambda<Action>(call);
var l = lambda.Compile();
l();
} /// <summary>
/// %
/// </summary>
private void Modulo()
{
Expression s1 = Expression.Constant();
Expression s2 = Expression.Constant();
var t = Expression.Modulo(s1,s2); Expression<Func<int>> lambda = Expression.Lambda<Func<int>>(t);
var l = lambda.Compile();
Console.WriteLine(l());
} /// <summary>
/// new
/// </summary>
private void New()
{
Expression s = Expression.Constant();
var t = Expression.New(typeof(T));
var call = Expression.Call(t, typeof(T).GetMethod("Test"));
Expression<Action> lambda = Expression.Lambda<Action>(call);
var l = lambda.Compile();
l();
} /// <summary>
/// 初始化数组对象new int[]{7}
/// </summary>
private void NewArray()
{
Expression s = Expression.Constant();
var t = Expression.NewArrayInit(typeof(int),s);
var call = Expression.Call(t, typeof(int[]).GetProperty("Length").GetGetMethod());
Expression<Func<int>> lambda = Expression.Lambda<Func<int>>(call);
var l = lambda.Compile();
Console.WriteLine(l());
} /// <summary>
/// new int[7]
/// </summary>
private void NewArrayBounds()
{
Expression s = Expression.Constant();
var t = Expression.NewArrayBounds(typeof(int), s);
var call = Expression.Call(t, typeof(int[]).GetProperty("Length").GetGetMethod());
Expression<Func<int>> lambda = Expression.Lambda<Func<int>>(call);
var l = lambda.Compile();
Console.WriteLine(l());
}
/// <summary>
/// new List<int>(){5}
/// </summary>
private void ListInit()
{
Expression s = Expression.Constant();
var lst = Expression.New(typeof(List<int>));
var t = Expression.ListInit(lst,s);
var call = Expression.Call(t, typeof(List<int>).GetProperty("Count").GetGetMethod());
Expression<Func<int>> lambda = Expression.Lambda<Func<int>>(call);
var l = lambda.Compile();
Console.WriteLine(l());
}
/// <summary>
/// var s=new S();s.Ids.Add(5);s.Ids.Add(7);
/// </summary>
private void ListBind()
{
Type s = typeof(S);
var n=Expression.New(s);
var ids=s.GetProperty("Ids");
var l=typeof(List<int>);
var n2 = Expression.New(l);
var e1 = Expression.ElementInit(l.GetMethod("Add"), Expression.Constant());
var e2 = Expression.ElementInit(l.GetMethod("Add"), Expression.Constant());
var lst = Expression.ListBind(ids,e1,e2);
var init=Expression.MemberInit(n,lst);
Expression<Func<S>> lambda = Expression.Lambda<Func<S>>(init);
var ln = lambda.Compile();
var o = ln();
Console.WriteLine(o);
}
/// <summary>
/// L_0000: ldarg.1
/// L_0001: call void [mscorlib]System.Console::WriteLine(int32)
/// L_0006: ldarg.s j2
/// L_0008: call void [mscorlib]System.Console::WriteLine(int32)
/// L_000d: ret
/// </summary>
private void TestArgs(int a, int b, int c, int d, int e, int f, int g, int h, int i, int j, int a1, int b1, int c1, int d1, int e1, int f1, int g1, int h1, int i1, int j1, int a2, int b2, int c2, int d2, int e2, int f2, int g2, int h2, int i2, int j2)
{ Console.WriteLine(a);
Console.WriteLine(j2);
}
}
}
Expression基础体验的更多相关文章
- Java 8 新特性之 Stream 流基础体验
Java 8 新特性之 Stream 流基础体验 package com.company; import java.util.ArrayList; import java.util.List; imp ...
- 零基础学习python 你该怎么做
本人文科生,回顾自己近 2 年的Python 自学经历,有一些学习心得和避坑经验分享给大家,让大家在学习 Python 的过程中少走一些弯路!减少遇到不必要的学习困难! 首先,最开始最大的困难应该就是 ...
- CI Weekly #4 | 不同规模的团队，如何做好持续集成？
CI Weekly 围绕『 软件工程效率提升』 进行一系列技术内容分享,包括国内外持续集成.持续交付,持续部署.自动化测试. DevOps 等实践教程.工具与资源,以及一些工程师文化相关的程序员 Ti ...
- MVC验证01-基础、远程验证
本文体验MVC服务端和客户端验证.主要涉及:※ 基础验证※ 远程验证1个或多个属性及注意点 基础体验 创建MVC4的Internet项目,本身包含了基本的Model,Views,Controller. ...
- H5 App设计者需要注意的21条禁忌
我们通常在做H5 APP设计的过程中,遇到很多看似很小,且很容易被忽略的问题,正是这些小问题,一次次的撩拨用户的耐心,让用户对你的APP心生怨念.现在WeX5君呕血为大家整理出H5 APP设计的21条 ...
- android 类似QQ底部输入框弹出键盘和面板冲突 布局闪动处理方案(转)
先看下效果 差不多就是解决这种冲突,布局闪动的 作者的githup :https://github.com/Jacksgong/JKeyboardPanelSwitch Android键盘面板冲突 布 ...
- 01Vue数据双向绑定
Vue作为前端MV*架构,Vue.js (读音 /vjuː/,类似于 view) 是一套构建用户界面的渐进式框架.与其他重量级框架不同的是,Vue 采用自底向上增量开发的设计. Vue 的核心库只关注 ...
- QQ音乐的动效歌词是如何实践的？
本文由云+社区发表 作者:QQ音乐技术团队 一. 背景 1. 现状 歌词浏览已经成为音乐app的标配,展示和动画效果也基本上大同小异,主要是单行的逐字染色的卡拉OK效果和多行的滚动效果.当然,我们也不 ...
- Java 11 正式发布，这 8 个逆天新特性教你写出更牛逼的代码
美国时间 09 月 25 日,Oralce 正式发布了 Java 11,这是据 Java 8 以后支持的首个长期版本. 为什么说是长期版本,看下面的官方发布的支持路线图表. 可以看出 Java 8 扩 ...
随机推荐
- SQL- @@ROWCOUNT -返回上一行执行影响的行行数
DECLARE @AFFECT INT declare @t table(name nvarchar(20),qy nvarchar(20),je int)insert into @t select ...
- 对java多态的理解
java多态,如何理解父类引用指向子类对象 要理解多态性,首先要知道什么是“向上转型”. 我定义了一个子类Cat,它继承了Animal类,那么后者就是前者是父类.我可以通过 Cat c = new C ...
- IO流（三）
五.Java序列化 概述 Java序列化是指把Java对象转换为字节序列的过程 Java反序列化是指把字节序列恢复为Java对象的过程 当两个Java进程进行通信时,发送方需要把这个Java对象转换为 ...
- nginx ../logs/nginx.pid" failed (2: No such file or directory)
[1]nginx.pid相关 (1)可能出现两种场景: 1.1 nginx.pid文件不存在 发生现象:nginx: [error] open() "/usr/local/lib/ubcsr ...
- qemu中的内存管理
qemu负责模拟虚机的外设,因此虚机的线性地址空间主要由qemu进行管理,也就是确定线性地址空间中哪段地址属于哪个设备或者DRAM或者其他的什么. 1.数据结构 1.RAMBLOCK (最直接接触ho ...
- redis 在 php 中的应用（key篇）
本文为我阅读了 redis参考手册 之后结合 博友的博客 编写,注意 php_redis 和 redis-cli 的区别(主要是返回值类型和参数用法) 目录: KEY(键) DEL ...
- mount挂载相关参数详解
mount [ -t 设备类型 ] [ -o 扩展参数 ] dev dir -t:指定mount挂载设备类型,常见的类型有nfs.ntfs.vfat.iso9660等: is09 ...
- Java中日期格式（String、Date、Calendar）的相互转换
package day20190318; import java.text.ParseException; import java.text.SimpleDateFormat; import java ...
- ProtoType原型和__Proto__原型链的详解
var arr = new Array(12,13,14,15,16,17,18); var arr2 = new Array(12,13); arr.sun=function(){ //用原型加Ar ...
- ArrayList迭代器源码分析
集合的遍历 Java集合框架中容器有很多种类,如下图中: 对于有索引的List集合可以通过for循环遍历集合: List<String> list = new ArrayList<& ...