public static bool IsSingleValuedLinq(LinqMethod linq)
{
return(linq switch
{
LinqMethod.First => true,
LinqMethod.FirstOrDefault => true,
LinqMethod.Last => true,
LinqMethod.LastOrDefault => true,
LinqMethod.Single => true,
LinqMethod.SingleOrDefault => true,
_ => false
});
public override void VisitInvocationExpression(InvocationExpression invocationExpression)
{
InvocationExpression outerInvocationExpression = invocationExpression;
//Note the invocations are in reverse order, so x.Foo().Bar() will have [0] be the Bar() and [1] be the Foo()
List <InvocationExpression> invocations = new List <InvocationExpression>();
LinqMethod outerMethod = null;
Expression target = null;
for (;;)
{
var resolveResult = ctx.Resolve(invocationExpression) as MemberResolveResult;
if (resolveResult == null || !(resolveResult.Member is IMethod))
{
break;
}
var method = LinqMethods.FirstOrDefault(candidate => candidate.FullName == resolveResult.Member.FullName &&
candidate.ParameterCount == ((IMethod)resolveResult.Member.MemberDefinition).Parameters.Count);
if (method == null || (invocations.Any() && method.IsLast))
{
break;
}
var mre = invocationExpression.Target as MemberReferenceExpression;
if (mre == null)
{
break;
}
if (outerMethod == null)
{
outerMethod = method;
}
invocations.Add(invocationExpression);
target = mre.Target;
var newInvocation = target as InvocationExpression;
if (newInvocation == null)
{
break;
}
invocationExpression = newInvocation;
}
if (target == null)
{
base.VisitInvocationExpression(invocationExpression);
return;
}
if (!outerMethod.IsPoorStyleAlone && invocations.Count == 1)
{
base.VisitInvocationExpression(invocationExpression);
return;
}
var currentTypeDeclaration = outerInvocationExpression.GetParent <TypeDeclaration>();
var currentTypeResolveResult = ctx.Resolve(currentTypeDeclaration) as TypeResolveResult;
if (currentTypeResolveResult == null)
{
base.VisitInvocationExpression(invocationExpression);
return;
}
var currentTypeDefinition = currentTypeResolveResult.Type.GetDefinition();
var targetResolveResult = ctx.Resolve(target);
if (!CanIndex(currentTypeDefinition, targetResolveResult))
{
base.VisitInvocationExpression(invocationExpression);
return;
}
string countPropertyName = GetCountProperty(currentTypeDefinition, targetResolveResult);
string lastInvocationName = ((MemberReferenceExpression)invocations[0].Target).MemberName;
bool endsReversed = invocations.Count(invocation => ((MemberReferenceExpression)invocation.Target).MemberName == "Reverse") % 2 != 0;
bool requiresCount = lastInvocationName == "Count" || lastInvocationName == "Any" ||
(endsReversed ? lastInvocationName == "First" || lastInvocationName == "ElementAt" : lastInvocationName == "Last");
if (countPropertyName == null && requiresCount)
{
base.VisitInvocationExpression(invocationExpression);
return;
}
AddIssue(new CodeIssue(invocations.Last().LParToken.StartLocation,
invocations.First().RParToken.EndLocation,
ctx.TranslateString("Use of Linq method when there's a better alternative"),
ctx.TranslateString("Replace method by simpler version"),
script => {
Expression startOffset = null;
Expression endOffset = null;
Expression expression = null;
bool reversed = false;
foreach (var invocation in invocations.AsEnumerable().Reverse())
{
string invocationName = ((MemberReferenceExpression)invocation.Target).MemberName;
switch (invocationName)
{
case "Skip":
Expression offset = reversed ? endOffset : startOffset;
if (offset == null)
{
offset = invocation.Arguments.Last().Clone();
}
else
{
offset = new BinaryOperatorExpression(offset,
BinaryOperatorType.Add,
invocation.Arguments.Last().Clone());
}
if (reversed)
{
endOffset = offset;
}
else
{
startOffset = offset;
}
break;
case "Reverse":
reversed = !reversed;
break;
case "First":
case "ElementAt":
case "Last":
{
bool fromEnd = (invocationName == "Last") ^ reversed;
Expression index = invocationName == "ElementAt" ? invocation.Arguments.Last().Clone() : null;
Expression baseOffset = fromEnd ? endOffset : startOffset;
//Our indexWithOffset is baseOffset + index
//A baseOffset/index of null is considered "0".
Expression indexWithOffset = baseOffset == null ? index :
index == null ? baseOffset :
new BinaryOperatorExpression(baseOffset, BinaryOperatorType.Add, index);
Expression indexerExpression = indexWithOffset;
if (fromEnd)
{
var endExpression = new BinaryOperatorExpression(new MemberReferenceExpression(target.Clone(), countPropertyName),
BinaryOperatorType.Subtract,
new PrimitiveExpression(1));
if (indexerExpression == null)
{
indexerExpression = endExpression;
}
else
{
indexerExpression = new BinaryOperatorExpression(endExpression,
BinaryOperatorType.Subtract,
new ParenthesizedExpression(indexerExpression));
}
}
indexerExpression = indexerExpression ?? new PrimitiveExpression(0);
var newExpression = new IndexerExpression(target.Clone(),
indexerExpression);
script.Replace(outerInvocationExpression, newExpression);
break;
}
case "Count":
case "Any":
{
Expression takenMembers;
if (startOffset == null)
{
takenMembers = endOffset;
}
else if (endOffset == null)
{
takenMembers = startOffset;
}
else
{
takenMembers = new BinaryOperatorExpression(startOffset,
BinaryOperatorType.Add,
endOffset);
}
var countExpression = new MemberReferenceExpression(target.Clone(), countPropertyName);
Expression newExpression;
if (invocationName == "Count")
{
if (takenMembers == null)
{
newExpression = countExpression;
}
else
{
newExpression = new BinaryOperatorExpression(countExpression,
BinaryOperatorType.Subtract,
new ParenthesizedExpression(takenMembers));
}
}
else
{
newExpression = new BinaryOperatorExpression(countExpression,
BinaryOperatorType.GreaterThan,
new ParenthesizedExpression(takenMembers));
}
script.Replace(outerInvocationExpression, newExpression);
break;
}
}
}
}));
base.VisitInvocationExpression(invocationExpression);
}
static void Main(string[] args)
{
#region ADO.NET HomeWork
// 作业：
//构建一个DBHelper，可以提供：
// 封装过后的ExecuteNonQuery() / ExecuteScalar() / ExecuteReader()方法
// 由外部控制开闭（Open() / Close()）的长连接（LongConnection）
// ExecuteNonQuery()使用长连接的重载
//使用上述DBHelper，完成以下操作：
// 将用户名和密码存入数据库：Register()
// 根据用户名和密码检查某用户能够成功登陆：Logon()
// 如果用户成功登陆，将其最后登录时间（LatestLogonTime）改成当前时间
// 批量标记若干Id的Message为已读：MarkHasRead(int[] messageIds)
// 查找出最近登录的若干个同学：IList<User> GetLatestLogon(int amount)
// 用事务完成帮帮币转移方法：void Sell(User buyer, int amount)，当前用户的帮帮币减少amount枚，买家（buyer）的帮帮币增加amount枚
#endregion
string connectionString = @"Data Source=-20191126PKLSWP;Initial Catalog=17bang;Integrated Security=True;";
using (DbConnection connection = new SqlConnection(connectionString))
{
connection.Open();
}
#region 双链foreach和max作业
DoubleLinkNode node1 = new DoubleLinkNode {
value = 1
};
DoubleLinkNode node2 = new DoubleLinkNode {
value = 2
};
DoubleLinkNode node3 = new DoubleLinkNode {
value = 3
};
DoubleLinkNode node4 = new DoubleLinkNode {
value = 4
};
DoubleLinkNode node5 = new DoubleLinkNode {
value = 5
};
node2.InsertAfter(node1);
node3.InsertAfter(node2);
node5.InsertAfter(node3);
foreach (var item in node1)
{
Console.WriteLine(((DoubleLinkNode)item).value);
}
//DoubleLink Max
DoubleLinkNode.Max(node1);
#endregion
#region 2020.4.14 5.在Main()函数调用ContentService时，捕获一切异常，并记录异常的消息和堆栈信息
User wpz = new User("wpzwpz", "1231231");
Problem problem = new Problem()
{
Reward = 2
};
Content content = new Content("王月半子")
{
Reward = problem, Author = wpz
};
try
{
ContentService contentService = new ContentService();
//我的理解，这个方法调用里已经有了各种抛异常的机制，
//那我这里就不用在写Throw了，如果有意外的异常catch就可以用了
contentService.Publish(content);
}
catch (Exception Record)
{
string path = @"C:\Users\Administrator\source\repos\luckstack3\Captcha\ForContentService.txt";
using (StreamWriter writer = File.AppendText(path))
{
DateTime date = DateTime.Now;//设置日志时间
string time = date.ToString("yyyy-mm-dd HH:mm:ss");
//日志存放
//writer = File.AppendText(path);
writer.WriteLine("异常时间" + time);
writer.WriteLine("异常对象" + Record.Source);
writer.WriteLine("调用堆栈" + Record.StackTrace.Trim());
writer.WriteLine("调用堆栈" + Record.ToString());
writer.Flush();
}
throw;
}
#endregion
#region Generic Method Homework Area
//1.声明一个委托：打水（ProvideWater），可以接受一个Person类的参数，返回值为int类型 【已完成】
ProvideWater getWater = TakeWater;
Person water = new Person();
//2-1.方法 【已完成】
getWater(water);
//2-2.匿名方法 【已完成】
ProvideOtherWater(water);
//2-3.lambda表达式
ProvideLambdaWater(water);
//3.声明一个方法GetWater()，该方法接受ProvideWater作为参数，并能将ProvideWater的返回值输出
GetWater(getWater);
#endregion
#region http://17bang.ren/Article/537 C#进阶：Linq方法 找出每个作者最近发布的一篇文章
//找出每个作者最近发布的一篇文章
LinqMethod.find_AuthorRecentlyArticle();
//为求助（Problem）添加悬赏（Reward）属性，并找出每一篇求助的悬赏都大于5个帮帮币的文章作者
LinqMethod.SearchReward();
#endregion
#region C# http://17bang.ren/Article/520 C#进阶：Linq-1：where/order/group/select
LinqMethod.Find_DFG_Article();
LinqMethod.Find_YU_Article();
LinqMethod.AscendingAndDescendingArticle();
LinqMethod.CountArticle();
LinqMethod.FindSpecefiedKeyWord();
LinqMethod.MaxCommentsOfArticle();
LinqMethod.MaxCommentsOfAuthor();
#endregion
#region 面向对象和C#基础作业（old）
#region 值的值传递和引用 之前作业完结
//int a = 18;
//HomeWork person = new HomeWork();//值的值传递
//person.ValuePass(a);
//Console.WriteLine(a);
//Console.WriteLine("------------------------");
//HomeWork otherPerson = new HomeWork();//值的引用传递
//otherPerson.ReferencePass(ref a);
//Console.WriteLine(a);
//Console.WriteLine("--------------------------");
//HomeWork name = new HomeWork { _name = "王月半子" };//引用类型的值传递
//ChangeName(name);
//Console.WriteLine(name._name);
//Console.WriteLine("--------------------------");
//HomeWork newName = new HomeWork { _name = "王月半子" };//引用类型的引用传递
//ChangeingName(ref newName);
//Console.WriteLine(newName._name);
#endregion
#region 第一天作业 观察“一起帮”的： 功能作业https://zhuanlan.zhihu.com/p/92362781
//User of class method.
//Entity.User User = new Entity.User();
//User.Register();
//User.Login();
////problem of class method ( inside null)
//Entity.Problem Problem = new Entity.Problem();
//Problem.Publish();
////HeloMoney of call method (inside null)
//Entity.HelpMoney Helomoney = new Entity.HelpMoney();
//Helomoney.BodyShow();
#endregion
#region Secend Day Homework. https://zhuanlan.zhihu.com/p/92470130
//1.user.Password在类的外部只能改不能读
//Entity.User Password = new Entity.User();
//Password.Password = "******";
//2.如果user.Name为“admin”，输入时修改为“系统管理员”
//Entity.User user = new Entity.User();
//user.UserName = "******";
//3.problem.Reward不能为负数
//Entity.Problem problem = new Entity.Problem();
//problem.Reward = -1;
//调用这些类的有参/无参构造函数，生成这些类的对象，调用他们的方法
//3. 一起帮的求助可以有多个（最多10个）关键字，请为其设置索引器，以便于我们通过其整数下标进行读写
//Entity.Problem problem = new Entity.Problem();
//Console.WriteLine(problem[52]);
//设计一种方式，保证：每一个Problem对象一定有Body赋值每一个User对象一定有Name和Password赋值
//Go to (Problem Page) OR (User Page )watch.
#endregion
#region Third Day Homework. https://zhuanlan.zhihu.com/p/95261748
//1.Publish()：发布一篇求助，并将其保存到数据库
//Entity.Problem problem = new Entity.Problem();
//problem.HelpMe();
///3.设计一个类FactoryContext，保证整个程序运行过程中，
///无论如何，外部只能获得它的唯一的一个实例化对象。（提示：设计模式之单例）
///
//new Entity.FactoryContext().Show(); // probably is private function make this red line...
///4.想一想，为什么Publish()方法不是放置在User类中呢？
///用户（user）发布（Publish）一篇文章（article）
///，不正好是user.Publish(article) 么？
///
///这里也有发布的啊，如果那里有需要发布，继承一个就好了，或者直接引用这里的方法就可以。
///如果这么说对的话，我还可以继续说，如果说的不对那就当我没说。
///5.自己实现一个模拟栈（MimicStack）类，入栈出栈数据均为int类型，包含如下功能：
///5.1出栈Pop()，弹出栈顶数据
///5.2入栈Push()，可以一次性压入多个数据
///5.3 出 / 入栈检查，
///5.4如果压入的数据已超过栈的深度（最大容量），提示“栈溢出”如果已弹出所有数据，提示“栈已空”
//MimicStack stack = new MimicStack();
//stack.push(223573);
//stack.pop();
//stack.pop();
//stack.push(123);
//stack.push(22743);
//stack.push(233);
//stack.push(22213);
//stack.pop();
//stack.push(32213);
//stack.push(52213);
//stack.push(2213);
//stack.pop();
//stack.push(22813);
//stack.push(22313);
//stack.push(224213);
//stack.push(92212463);
//stack.push(1);
//stack.push(1);
//stack.push(1);
//stack.push(1);
//stack.pop();
//stack.pop();
//stack.pop();
//stack.pop();
//stack.pop();
//stack.pop();
//stack.pop();
//stack.pop();
//stack.pop();
//stack.pop();
//stack.pop();
//stack.pop();
//3.实例化文章和意见建议，调用他们：继承自父类的属性和方法自己的属性和方法
// it's for parents
//Entity.Content content = new Article();//here is for article page.
//content.Release();
//content = new Problem();//here is for problem page.
//content.Release();
//content = new Suggest();//here is for suggest page.
//content.Release();
//Article article = new Article();
//4.再为之前所有类（含User、HelpMoney等）抽象一个基类：Entity，
//包含一个只读的Id属性。试一试，Suggest能有Id属性么？
///只是把任务要求造出来了，具体啥意思也不知道。suggest ID指的是啥？？？
///这个作业后补。
#endregion
#region Fourth Day Homework "多态" https://zhuanlan.zhihu.com/p/93053223
///1.添加一个新类ContentService，其中有一个发布（Publish()）方法：
/// 如果发布Article，需要消耗一个帮帮币
/// 如果发布Problem，需要消耗其设置悬赏数量的帮帮币
/// 如果发布Suggest，不需要消耗帮帮币
///最后将内容存到数据库中，三个类存数据库的方法是完全一样的，
///现在用Console.WriteLine()代替。根据我们学习的继承和多态知识，实现上述功能。
///
///
///maybe i made big mistake.homework write not like this.---T_T||...
//ContentService contentService = new ContentService("Article",20);
//contentService.publish();
#endregion
#region Fifth Day 思考之前的Content类，该将其抽象成抽象类还是接口？https://zhuanlan.zhihu.com/p/93224519
///1.思考之前的Content类，该将其抽象成抽象类还是接口？为什么？并按你的想法实现。
///
//思考应该用interface接口，但是一改Errors爆满，无从下手改。。。。
///2.一起帮里的求助总结、文章和意见建议，以及他们的评论，
///都有一个点赞（Agree）/踩（Disagree）的功能，赞和踩都会增减作者及评价者的帮帮点。
///能不能对其进行抽象？如何实现？
///
#endregion
#region Six Day 1.用代码证明struct定义的类型是值类型 栈的学费是按周计费的，所以请实现这两个功能：
//1.用代码证明struct定义的类型是值类型 (MyClass and MyStruct at this page.)
//MyClass myClass = new MyClass();
/*myClass._test = 23;*/ //这里的23是赋值到一个地址里面去。
//MyStruct myStruct = new MyStruct();
/*myStruct._test = 23;*/ //这里是值类型。
/// 1.函数GetDate()，能计算一个日期若干（日/周/月）后的日期
///2.给定任意一个年份，就能按周排列显示每周的起始日期，如下图所示：
//DataTimeCount.GetWeek(2000);
#endregion
#region Seven Day homework about Token
//TokenManager tokenManager = new TokenManager();
//tokenManager.Add(Token.Admin);
//tokenManager.Add(Token.Blogger);
//tokenManager.Add(Token.Registered);
//tokenManager.Remove(Token.Blogger);
//tokenManager.Has(Token.Admin);
#endregion
#region https://zhuanlan.zhihu.com/p/93458057C#-面向对象-万物皆对象：Object和装箱拆箱
///1.思考dynamic和var的区别，并用代码予以演示
///
//请忽略命名，命名采用var的第一个字母，和一个随便的i,dynamic也是一样
//var Vi = "88";
//dynamic Di = "88";
//区别在于，var是推倒类型，在使用中因为vi被推导为string类型所以无法完成表达式
//无法通过编译，所以直接报错。
//Console.WriteLine(Vi - 8);
//dynamic是动态类型，在编译时默认跳过，所以不会有报错的发生，但如果运行时候会报运行错误
//结果是一样的。
//Console.WriteLine(Di-8);
//2.构造一个能装任何数据的数组，并完成数据的读写
//我不知道还有什么类型了，字符串，数字，元组，bool,小数，数组，应该差不多了。
//object[] AnyArray = { "王胖子很帅", 26, (23, "17cm"), new Student() ,true ,888.8,new int [17,18,19,20,22]};
//for (int i = 0; i < AnyArray.Length-1; i++)
//{//想不到我现在竟然可以随手就写一个完美的循环出来。
// Console.WriteLine(AnyArray[i]);
//}
//Console.WriteLine(AnyArray);
//3.使用object改造数据结构栈（Stack），并在出栈时获得出栈元素
//都已经如此完美了，还怎么优化。。。
///
#endregion
#region https://zhuanlan.zhihu.com/p/93440022C#-面向对象-反射和特性
//2.在Content之外封装一个方法，可以修改Content的CreateTime和PublishTime
//FixTime.FixContentTime(2019, 10, 19);
///3.自定义一个特性HelpMoneyChanged（帮帮币变化）：
///1.该特性只能用于方法
///2.有一个构造函数，可以接受一个int类型的参数amount，表示帮帮币变化的数量
///3.有一个string类型的Message属性，记录帮帮币变化的原因
///
//作业在User页面
///5.用反射获取Publish()上的特性实例，输出其中包含的信息
///
//这个地方有BUG，把自己写迷糊了。歇会儿换个思路，如果换不出来就等飞哥来换。
//思路是这样的，我要使用GetHM这个函数，必须有一个参数，参数需要找Publish这个方法要
//要找publish方法首先我需要有一个contentservice这个对象，有了这个对象，还得给publish传参...我的天
//ContentService service = new ContentService();
//service = service.Publish(Article article);
//GetPublish.GetHM(service);
#endregion
#region https://zhuanlan.zhihu.com/p/93747718 C#-面向对象：string还是StringBuilder？
///确保文章（Article）的标题不能为null值，也不能为一个或多个空字符组成的字符串，
///而且如果标题前后有空格，也予以删除
///
//Article wpz1 = new Article(string.Empty);
//Article wpz2 = new Article(" ");
//Article wpz3 = new Article(null);
//Article wpz4 = new Article("");
//Article wpz5 = new Article(" ");
//Article wpz = new Article(" 王胖子比飞哥帅的多 ");
//设计一个适用的机制，能确保用户（User）的昵称（Name）不能含有admin、17bang、管理员等敏感词。
//User wpz4 = new User("qqadminw", "~qweqwe");
//User wpz5 = new User("wwadminw", "!qweqwe");
//User wpz6 = new User("adminee", "@qwe123");
//User wpz7 = new User("adminee", "@qwe123");
//User wpz8 = new User("qq17bang", "@qwe123");
//User wpz9 = new User("qq17bangww", "@qwe123");
///确保用户（User）的密码（Password）：长度不低于6
///必须由大小写英语单词、数字和特殊符号（~!@#$%^&*()_+）组成
///
//这个密码应该还差点东西没写对
//User user = new User("", "abcabc");
//User user1 = new User("", "==abcabc");
//User wpz = new User("admin", "~!@# $%^&*()_+");
//User wpz1 = new User("admin", "~qw---eqwe");
//User wpz2 = new User("admin", "!qweqwe");
//User wpz3 = new User("admin", "@qwe123");
#endregion
#endregion
#region Practies area.. Here is not homeword,just selftry.
//Self wang = new Self();
//Type typeinfo = typeof(Self);
//FieldInfo wangpz = typeinfo.GetField("_try", BindingFlags.NonPublic | BindingFlags.Instance);
//object Try = wangpz.GetValue(wang);
//Console.WriteLine(Try);
//Self yb = new Self();
//Type diyibu = typeof(Self);
//FieldInfo dierbu = diyibu.GetField("_iTry", BindingFlags.NonPublic |BindingFlags.Instance| BindingFlags.GetProperty);
//object disubu = dierbu.GetValue(yb);
//Console.WriteLine(disubu);
//disubu = 222;
//Console.WriteLine(disubu);
//Self self = new Self();
//Console.WriteLine(self);
//object tlzz = new Student();
//NowTry.Praise(tlzz);
//object wpz = new Teacher();
//NowTry.Praise(wpz);
//string name = string.Empty;
//if (student ==null)
//{
// name = "无姓名";
//}
//else
//{
// name = student.name;
//}
//string name = student == null ? "无姓名" : student.name;
//student student =null;
//Console.WriteLine(student?.IsMale);
//bool? gender = student?.IsMale;
//gender = false;
//int[] vs = new int[] { 16, 23, 25, 22 };
//List<int> ages = new List<int> {16,23,25,22 };
//IEnumerator<int> enumerator = ages.GetEnumerator();
//while (enumerator.MoveNext())
//{
// Console.WriteLine(enumerator.Current);
//}
//LinkedList
#endregion
}
