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if (x in (1, 2, 3)) if (x in 1:5)if (x between(1,5)) |
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public Tuple<string, int, double> ReturnMyTuple() { return "Hello World!", 42, 4.2; } // elsewhere: item1 is a string, item2 is an int, item3 is a double. var item1, item2, item3 = ReturnMyTuple(); |
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switch (anInt) { case 1, 2: Console.WriteLine("1 or 2"); break; case 3..9: Console.WriteLine("3 to 9"); break; case >= 10: Console.WriteLine("10 or higher"); break; default: ... } |
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switch (aString) { case "one", "two": Console.WriteLine("1 or 2"); break; case "three": Console.WriteLine("3"); break; default: ... } |
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switch (aString) { case .IsNullOrEmpty(): ... case .Length > 100: ... case .Contains("foo"): ... } |
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Void DoX(MyClass! obj) { … }// The following would make the compiler say: // "Cannot convert string to string!, an explicit conversion existsstring! nonNullable = someFunctionThatReturnsAString(); |
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DelegateType! DelegateVar; |
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// Instead of doing:var obj = Foo(); Bar value = null; if(obj.Bar != null && obj.Bar.Something != null) { value = obj.Bar.Something.DoSomething(); } //You can do this with Groovy‘s null safe member operator ?.var obj = Foo(); var value = obj?.Bar?.Something?.DoSomething(); |
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MyClass value = null; int something = value.x.y ??? 0;//something is now 0 |
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// instead ofif (a != null && a.SomeProperty != null && a.SomeProperty.SomeField != null). // do this:IfNotNull(a.SomeProperty.SomeField) |
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public T Foo<T>(T blah) where T : number { return blah * blah; } |
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public void DoSomething<T>(T enum) where T : System.Enum { ... } |
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public static int Sum<T>(IEnumerable<T> seq) where T : operator(T=T+T){ .. } |
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where new(int, string) |
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public T Create<T>() where T : static Create() { return T.Create(); } |
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Derive from T:class Foo<T> : T where T : class Constraint for interfaces:class Foo<T> where T : interface |
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public string Name { get; set; } = "some value"; |
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public int SomeValue { get; private readonly set; } |
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Currently, this would take:var obj = new Foo(); object temp = obj .GetType() .GetProperty(aVariable) .GetValue(obj, null); int value = (int)temp .GetType() .GetMethod("Method") .Invoke(temp, null); What we want:dynamic obj = new Foo(); int value = obj[aVariable].Method(); |
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var obj = new dynamic { Foo = 1, Bar = "string" }; obj.Foo = 2; obj.NewProperty = Something(); obj["Bar"] = "a new value"; |
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class Foo { public int ID { get; set; } public string Name { get; set; } } .. private Foo# _member; public Foo# Something { get { return _member; } } |
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public override IEnumerable<int> Foo() { yield return 1; yield return 2; foreach(var i in base.Foo()) yield i; } //allowing me to write:public override IEnumerable<int> Foo() { yield return 1; yield return 2; yield foreach base.Foo(); } |
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[SomeCoolAttribute(s=>s.Foo)] public string MyProp { get; set; } |
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11. Enum的扩展 |
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Enum<String> Options{ Option1 = "xxx" Option2 = "yyy" } |
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public Notifyable<int> Foo { get; set; } |
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try { } catch (ArgumentOutOfRangeException) catch (ArgumentNullException) { // Catch a ArgumentOutOfRangeException or a ArgumentNullException } |
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// Instead of:using System; class Program { static void Main(string[] args) { Console.WriteLine(fact(10)); Console.ReadLine(); } static int fact(int n) { if (n == 0) return 1; else return n * fact(n - 1); } } // Use this:static int fact(int n) { if (n == 0) return 1; else return n * fact(n - 1); } Console.WriteLine(fact(10)); Console.ReadLine(); |
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// Instead of: // copy ref to delegate for thread safety var evt = this.ApplicationTextUpdated; if (evt != null) evt(this, new EventArgs<string>(applicationText)); // do this Fire(this.ApplicationTextUpdated(this, new EventArgs<string>(applicationText)); |
老外畅想C# 5.0这个可以有,布布扣,bubuko.com
原文：http://www.cnblogs.com/passer/p/3633454.html