在我从这个问题中了解到以下内容后，我想到了这一点 ：

where T : struct

我们 C＃开发人员都知道 C＃的基础知识。我的意思是声明，条件，循环，运算符等。

我们中的一些人甚至掌握了Generics ， 匿名类型 ， lambdas ， LINQ等......

但是，即使 C＃粉丝，瘾君子，专家几乎不知道 C＃最隐藏的功能或技巧是什么？

以下是目前显示的功能：

Keywords

• yield by Michael Stum
• var by Michael Stum
• using() statement by kokos
• readonly by kokos
• as by Mike Stone
• as / is by Ed Swangren
• as / is (improved) by Rocketpants
• default by deathofrats
• global:: by pzycoman
• using() blocks by AlexCuse
• volatile by Jakub Šturc
• extern alias by Jakub Šturc

Attributes

• DefaultValueAttribute by Michael Stum
• ObsoleteAttribute by DannySmurf
• DebuggerDisplayAttribute by Stu
• DebuggerBrowsable and DebuggerStepThrough by bdukes
• ThreadStaticAttribute by marxidad
• FlagsAttribute by Martin Clarke
• ConditionalAttribute by AndrewBurns

Syntax

• ?? (coalesce nulls) operator by kokos
• Number flaggings by Nick Berardi
• where T:new by Lars Mæhlum
• Implicit generics by Keith
• One-parameter lambdas by Keith
• Auto properties by Keith
• Namespace aliases by Keith
• Verbatim string literals with @ by Patrick
• enum values by lfoust
• @variablenames by marxidad
• event operators by marxidad
• Format string brackets by Portman
• Property accessor accessibility modifiers by xanadont
• Conditional (ternary) operator (?:) by JasonS
• checked and unchecked operators by Binoj Antony
• implicit and explicit operators by Flory

Language Features

• Nullable types by Brad Barker
• Anonymous types by Keith
• __makeref __reftype __refvalue by Judah Himango
• Object initializers by lomaxx
• Format strings by David in Dakota
• Extension Methods by marxidad
• partial methods by Jon Erickson
• Preprocessor directives by John Asbeck
• DEBUG pre-processor directive by Robert Durgin
• Operator overloading by SefBkn
• Type inferrence by chakrit
• Boolean operators taken to next level by Rob Gough
• Pass value-type variable as interface without boxing by Roman Boiko
• Programmatically determine declared variable type by Roman Boiko
• Static Constructors by Chris
• Easier-on-the-eyes / condensed ORM-mapping using LINQ by roosteronacid
• __arglist by Zac Bowling

Visual Studio Features

• Select block of text in editor by Himadri
• Snippets by DannySmurf

Framework

• TransactionScope by KiwiBastard
• DependantTransaction by KiwiBastard
• Nullable<T> by IainMH
• Mutex by Diago
• System.IO.Path by ageektrapped
• WeakReference by Juan Manuel

Methods and Properties

• String.IsNullOrEmpty() method by KiwiBastard
• List.ForEach() method by KiwiBastard
• BeginInvoke(), EndInvoke() methods by Will Dean
• Nullable<T>.HasValue and Nullable<T>.Value properties by Rismo
• GetValueOrDefault method by John Sheehan

Tips & Tricks

• Nice method for event handlers by Andreas H.R. Nilsson
• Uppercase comparisons by John
• Access anonymous types without reflection by dp
• A quick way to lazily instantiate collection properties by Will
• JavaScript-like anonymous inline-functions by roosteronacid

Other

• netmodules by kokos
• LINQBridge by Duncan Smart
• Parallel Extensions by Joel Coehoorn

这不是 C＃本身，但我没有看到任何人真正使用System.IO.Path.Combine()到他们应该的程度。事实上，整个 Path 类非常有用，但没有人使用它！

我愿意打赌每个生产应用程序都有以下代码，即使它不应该：

string path = dir + "\\" + fileName;

lambdas 和类型推理被低估了。 Lambdas 可以有多个语句 ，它们会自动兼容为兼容的委托对象 （只需确保签名匹配），如下所示：

Console.CancelKeyPress +=
    (sender, e) => {
        Console.WriteLine("CTRL+C detected!\n");
        e.Cancel = true;
    };

请注意，我没有new CancellationEventHandler也没有指定sender和e类型，它们可以从事件中推断出来。这就是为什么编写整个delegate (blah blah)并不需要你指定参数类型的麻烦。

Lambdas 不需要返回任何东西 ，类型推断在这样的上下文中非常强大。

顺便说一下，你可以随时返回Lambdas，它们在函数式编程意义上使 Lambdas成为可能。例如，这是一个 lambda，它使 lambda 处理 Button.Click 事件：

Func<int, int, EventHandler> makeHandler =
    (dx, dy) => (sender, e) => {
        var btn = (Button) sender;
        btn.Top += dy;
        btn.Left += dx;
    };

btnUp.Click += makeHandler(0, -1);
btnDown.Click += makeHandler(0, 1);
btnLeft.Click += makeHandler(-1, 0);
btnRight.Click += makeHandler(1, 0);

注意链接： (dx, dy) => (sender, e) =>

这就是为什么我很高兴参加函数式编程课程:-)

除了 C 中的指针，我认为这是你应该学习的另一个基本的东西:-)

来自Rick Strahl ：

你可以链？运算符，以便您可以进行一堆空比较。

string result = value1 ?? value2 ?? value3 ?? String.Empty;