C# 6.0 新特性汇总
1. 静态using(static using) 静态using声明允许不使用类名直接调用静态方法。 The static using declaration allows invoking static methods without the class name. In C# 5 using System; Console.WriteLine("Hello,World!"); In C# 6 using static System.Console; WriteLine("Hello,World"); 2. 表达式方法(Expression-Bodied Methods) 使用表达式方法,只有一条语句的方法可以使用lambda语法写。 With expression-bodied methods,a method that includes just one statement can be written with the lambda syntax. In C# 5 public bool IsSquare(Rectangle rect) { return rect.Height == rect.Width; } In C# 6 public bool IsSquare(Rectangle rect) => rect.Height == rect.Width; 3. 表达式属性(Expression-Bodied Properties) 跟表达式方法类似,只有一个get访问器的单行属性可以使用lambda语法写。 Similar to expression-bodied methods,one-line properties with only a get accessor can be written with the lambda syntax In C# 5 public string FullName { get { return FirstName +"" + LastName; } } In C# 6 public string FullName => FirstName +"" + LastName; 4. 自动属性初始化器(Auto-Implemented Property Intializers) 自动属性可以使用属性初始化器初始化。 Auto-implemented properties can be initialized with a property initializer. In C# 5 public class Person { public Person() { Age = 24; } public int Age {get; set;} } In C# 6 public class Person { public int Age {get; set;} = 42; } 5. 只读自动属性(Read-Only Auto Properties) C# 5需要完整的属性语法实现只读属性,C# 6可以使用自动属性实现。 To implement read-only properties,C# 5 requires the full property syntax. With C# 6,you can do this using auto-implemented properties. In C# 5 private readonly int _bookId; public BookId { get { return _bookId; } } In C# 6 public BookId {get;} 6. nameof操作符(nameof Operator) 字段、属性、方法和类型的name可以通过nameof访问。使用nameof,可以方便的重构name变化。 With the new nameof operator,names of fields,properties,methods,or types can be accessed. With this,name changes are not missed with refactoring. In C# 5 public void Method(object o) { if (o == null) throw new ArgumentNullException("o"); In C# 6 public void Method(object o) { if (o == null) throw new ArgumentNullException(nameof(o)); 7. Null传递操作符(Null Propagation Operator) Null传递操作符简化了空值检查。 The null propagation operator simplifies null checks. In C# 5 int? age = p == null ? null : p.Age; var handler = Event; if (handler != null) { handler(source,e); } In C# 6 int? age = p?.Age; handler?.Invoke(source,e); 8. 字符串插值(String Interpolation) 字符串差值移除了对string.Format的调用,使用表达式占位符取代数字格式占位符。 The string interpolation removes calls to string.Format. Instead of using numbered format placeholders in the string,the placeholders can include expressions. In C# 5 public override ToString() { return string.Format("{0},{1}",Title,Publisher); } In C# 6 public override ToString() => $"{Title} {Publisher}"; 9. 字典初始化器(Dictionary Initializers) 字典可以使用类似集合的字典初始化器初始化。 Dictionaries can now be initialized with a dictionary initializer―similar to the collection initializer. In C# 5 var dict = new Dictionary<int,string>(); dict.Add(3,"three"); dict.Add(7,"seven"); In C# 6 var dict = new Dictionary<int,string>() { [3] ="three",[7] ="seven" }; 10. 异常过滤器(Exception Filters) 异常过滤器允许你在捕获异常前进行过滤。 Exception filters allow you to filter exceptions before catching them. In C# 5 try { //etc. } catch (MyException ex) { if (ex.ErrorCode != 405) throw; // etc. } In C# 6 try { //etc. } catch (MyException ex) when (ex.ErrorCode == 405) { // etc. } 11. 在Catch使用Await(Await in Catch) await可以在catch块中直接使用,C# 5中需要变通使用。 await can now be used in the catch clause. C# 5 required a workaround. In C# 5 bool hasError = false; string errorMessage = null; try { //etc. } catch (MyException ex) { hasError = true; errorMessage = ex.Message; } if (hasError) { await new MessageDialog().ShowAsync(errorMessage); } In C# 6 try { //etc. } catch (MyException ex) { await new MessageDialog().ShowAsync(ex.Message); } 以上所述是小编给大家介绍的C# 6.0 新特性汇总,希望对大家有所帮助,如果大家有任何疑问请给我留言,小编会及时回复大家的。在此也非常感谢大家对编程小技巧网站的支持! (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |