重载构造函数:

using System;

public class Wine
{
public decimal Price;
public int Year;
public Wine (decimal price) { Price = price; }
public Wine (decimal price, int year) : this (price) { Year = year; }
}

对象初始化:

public class Bunny
{
public string Name;
public bool LikesCarrots;
public bool LikesHumans; public Bunny () {}
public Bunny (string n) { Name = n; }
}
Bunny b1 = new Bunny { Name="Bo", LikesCarrots=true, LikesHumans=false };
Bunny b2 = new Bunny ("Bo") { LikesCarrots=true, LikesHumans=false };

this引用:

public class Panda
{
public Panda Mate; public void Marry (Panda partner)
{
Mate = partner;
partner.Mate = this;
}
}
public class Test
{
string name;
public Test (string name) { this.name = name; }
}

属性:

public class Stock
{
decimal currentPrice; // The private "backing" field public decimal CurrentPrice // The public property
{
get { return currentPrice; } set { currentPrice = value; }
}
}

只读和已计算属性:

public class Stock
{
string symbol;
decimal purchasePrice, currentPrice;
long sharesOwned; public Stock (string symbol, decimal purchasePrice, long sharesOwned)
{
this.symbol = symbol;
this.purchasePrice = currentPrice = purchasePrice;
this.sharesOwned = sharesOwned;
} public decimal CurrentPrice { get { return currentPrice; }
set { currentPrice = value; } }
public string Symbol { get { return symbol; } }
public decimal PurchasePrice { get { return purchasePrice; } }
public long SharesOwned { get { return sharesOwned; } }
public decimal Worth { get { return CurrentPrice*SharesOwned; } }
} class Test
{
static void Main()
{
Stock msft = new Stock ("MSFT", 20, 1000);
Console.WriteLine (msft.Worth); // 20000
msft.CurrentPrice = 30;
Console.WriteLine (msft.Worth); // 30000
}
}

自动属性:

public class Stock
{
// ...
public decimal CurrentPrice { get; set; }
}

get 和 set 访问:

public class Foo
{
private decimal x;
public decimal X
{
get {return x;}
internal set {x = value;}
}
}

实现索引:

public class Portfolio
{
Stock[] stocks;
public Portfolio (int numberOfStocks)
{
stocks = new Stock [numberOfStocks];
} public int NumberOfStocks { get { return stocks.Length; } } public Stock this [int index] // indexer
{
get { return stocks [index]; }
set { stocks [index] = value; }
}
} class Test
{
static void Main()
{
Portfolio portfolio = new Portfolio(3);
portfolio [0] = new Stock ("MSFT", 20, 1000);
portfolio [1] = new Stock ("GOOG", 300, 100);
portfolio [2] = new Stock ("EBAY", 33, 77); for (int i = 0; i < portfolio.NumberOfStocks; i++)
Console.WriteLine (portfolio[i].Symbol);
}
}

多索引:

public class Portfolio
{
...
public Stock this[string symbol]
{
get
{
foreach (Stock s in stocks)
if (s.Symbol == symbol)
return s;
return null;
}
}
}

静态构造函数:

class Test
{
static Test()
{
Console.WriteLine ("Type Initialized");
}
}

Partial方法:

// PaymentFormGen.cs — auto-generated
partial class PaymentForm
{
// ...
partial void ValidatePayment(decimal amount);
}
// PaymentForm.cs — hand-authored
partial class PaymentForm
{
// ...
// partial void ValidatePayment(decimal amount)
{
if (amount > 100)
{
// ...
}
}
}

继承:

public class Asset
{
public string Name;
public decimal PurchasePrice, CurrentPrice;
}
public class Stock : Asset   // inherits from Asset
{
public long SharesOwned;
} public class House : Asset // inherits from Asset
{
public decimal Mortgage;
} class Test
{
static void Main()
{
Stock msft = new Stock()
{ Name="MSFT", PurchasePrice=20, CurrentPrice=30, SharesOwned=1000 }; House mansion = new House
{ Name="McMansion", PurchasePrice=300000, CurrentPrice=200000,
Mortgage=250000 }; Console.WriteLine (msft.Name); // MSFT
Console.WriteLine (mansion.Name); // McMansion Console.WriteLine (msft.SharesOwned); // 1000
Console.WriteLine (mansion.Mortgage); // 250000
}
}

多态:

class Test
{
static void Main()
{
Stock msft = new Stock ... ;
House mansion = new House ... ;
Display (msft);
Display (mansion);
} public static void Display (Asset asset)
{
System.Console.WriteLine (asset.Name);
}
}
static void Main() { Display (new Asset()); }    // Compile-time error

public static void Display (House house)         // Will not accept Asset
{
System.Console.WriteLine (house.Mortgage);
}

向下转换:

Stock msft = new Stock();
Asset a = msft; // upcast
Stock s = (Stock)a; // downcast
Console.WriteLine (s.SharesOwned); // <No error>
Console.WriteLine (s == a); // true
Console.WriteLine (s == msft); // true

虚拟函数成员:

public class Asset
{
...
public virtual decimal Liability { get { return 0; } }
}
public class Stock : Asset { ... }

public class House : Asset
{
...
public override decimal Liability { get { return Mortgage; } }
}
House mansion = new House
{ Name="McMansion", PurchasePrice=300000, CurrentPrice=200000,
Mortgage=250000 }; Asset a = mansion;
decimal d2 = mansion.Liability; // 250000

抽象类和抽象成员:

public abstract class Asset
{
...
public abstract decimal NetValue { get; } // Note empty implementation
} public class Stock : Asset
{
... // Override an abstract method
public override decimal NetValue // just like a virtual method.
{
get { return CurrentPrice * SharesOwned; }
}
} public class House : Asset // Every non abstract subtype must
{ // define NetValue.
...
public override decimal NetValue
{
get { return CurrentPrice - Mortgage; }
}
}

new 和 virtual

public class BaseClass
{
public virtual void Foo() { Console.WriteLine ("BaseClass.Foo"); }
} public class Overrider : BaseClass
{
public override void Foo() { Console.WriteLine ("Overrider.Foo"); }
} public class Hider : BaseClass
{
public new void Foo() { Console.WriteLine ("Hider.Foo"); }
}
Overrider o = new Overrider();
BaseClass b1 = o;
o.Foo(); // Overrider.Foo
b1.Foo(); // Overrider.Foo Hider h = new Hider();
BaseClass b2 = h;
h.Foo(); // Hider.Foo
b2.Foo(); // BaseClass.Foo

GetType() 和 typeof

using System;

public class Point {public int X, Y;}

class Test
{
static void Main()
{
Point p = new Point();
Console.WriteLine (p.GetType().Name); // Point
Console.WriteLine (typeof (Point).Name); // Point
Console.WriteLine (p.GetType() == typeof(Point)); // True
Console.WriteLine (p.X.GetType().Name); // Int32
Console.WriteLine (p.Y.GetType().FullName); // System.Int32
}
}

显式接口实现:

interface I1 { void Foo(); }
interface I2 { int Foo(); } public class Widget : I1, I2
{
public void Foo ()
{
Console.WriteLine ("Widget's implementation of I1.Foo");
} int I2.Foo ()
{
Console.WriteLine ("Widget's implementation of I2.Foo");
return 42;
}
}
Widget w = new Widget();
w.Foo(); // Widget's implementation of I1.Foo
((I1)w).Foo(); // Widget's implementation of I1.Foo
((I2)w).Foo(); // Widget's implementation of I2.Foo

虚拟地实现接口成员:

public interface IUndoable { void Undo(); }

public class TextBox : IUndoable
{
public virtual void Undo()
{
Console.WriteLine ("TextBox.Undo");
}
} public class RichTextBox : TextBox
{
public override void Undo()
{
Console.WriteLine ("RichTextBox.Undo");
}
}
RichTextBox r = new RichTextBox();
r.Undo(); // RichTextBox.Undo
((IUndoable)r).Undo(); // RichTextBox.Undo
((TextBox)r).Undo(); // RichTextBox.Undo

在子类中重新实现一个接口:

public interface IUndoable { void Undo(); }

public class TextBox : IUndoable
{
void IUndoable.Undo() { Console.WriteLine ("TextBox.Undo"); }
} public class RichTextBox : TextBox, IUndoable
{
public new void Undo() { Console.WriteLine ("RichTextBox.Undo"); }
}
RichTextBox r = new RichTextBox();
r.Undo(); // RichTextBox.Undo Case 1
((IUndoable)r).Undo(); // RichTextBox.Undo Case 2
public class TextBox : IUndoable
{
public void Undo() { Console.WriteLine ("TextBox.Undo"); }
}
RichTextBox r = new RichTextBox();
r.Undo(); // RichTextBox.Undo Case 1
((IUndoable)r).Undo(); // RichTextBox.Undo Case 2
((TextBox)r).Undo(); // TextBox.Undo Case 3

替代接口重新实现:

public class TextBox : IUndoable
{
void IUndoable.Undo() { Undo(); } // Calls method below
protected virtual void Undo() { Console.WriteLine ("TextBox.Undo"); }
} public class RichTextBox : TextBox
{
protected override void Undo() { Console.WriteLine ("RichTextBox.Undo"); }
}

Flags enums枚举:

[Flags]
public enum BorderSides { Left=1, Right=2, Top=4, Bottom=8 }
BorderSides leftRight = BorderSides.Left | BorderSides.Right;

if ((leftRight & BorderSides.Left) != 0)
System.Console.WriteLine ("Includes Left"); // Includes Left string formatted = leftRight.ToString(); // "Left, Right" BorderSides s = BorderSides.Left;
s |= BorderSides.Right;
Console.WriteLine (s == leftRight); // True s ^= BorderSides.Right; // Toggles BorderSides.Right
Console.WriteLine (s); // Left

Enum枚举类型安全问题:

static bool IsFlagDefined (Enum e)
{
decimal d;
return ! decimal.TryParse(e.ToString(), out d);
} [Flags]
public enum BorderSides { Left=1, Right=2, Top=4, Bottom=8 } static void Main()
{
for (int i = 0; i <= 16; i++)
{
BorderSides side = (BorderSides)i;
Console.WriteLine (IsFlagDefined (side) + " " + side);
}
}

泛型:

public class Stack<T>
{
int position;
T[] data = new T[100];
public void Push (T obj) { data[position++] = obj; }
public T Pop () { return data[--position]; }
}
Stack<int> stack = new Stack<int>();
stack.Push(5);
stack.Push(10);
int x = stack.Pop();

泛方法:

static void Swap<T> (ref T a, ref T b)
{
T temp = b;
a = b;
b = temp;
}

默认泛值:

static void Zap<T> (T[] array)
{
for (int i = 0; i < array.Length; i++)
array[i] = default(T);
}

约束:

static T Max <T> (T a, T b) where T : IComparable<T>
{
return a.CompareTo (b) > 0 ? a : b;
}
static void Initialize<T> (T[] array) where T : new()
{
for (int i = 0; i < array.Length; i++)
array[i] = new T();
}
class Stack<T>
{
Stack<U> FilteredStack<U>() where U : T {...}
}

泛型和协方差:

class Animal {}
class Bear : Animal {}
public class ZooCleaner
{
public static void Wash<T> (Stack<T> animals) where T : Animal {}
}
Stack<Bear> bears = new Stack<Bear>();
ZooCleaner.Wash (bears);

自引用泛型声明:

interface IEquatable<T> { bool Equals (T obj); }

public class Balloon : IEquatable<Balloon>
{
string color;
int cc; public bool Equals (Balloon b)
{
if (b == null) return false;
return b.color == color && b.cc == cc;
}
}

泛型类型中的静态数据的唯一性:

public class Bob<T> { public static int Count; }

class Test
{
static void Main()
{
Console.WriteLine (++Bob<int>.Count); // 1
Console.WriteLine (++Bob<int>.Count); // 2
Console.WriteLine (++Bob<string>.Count); // 1
Console.WriteLine (++Bob<object>.Count); // 1
}
}

对象初始化:

List<int> list = new List<int> {1, 2, 3};

在C#中创建类型的更多相关文章

  1. C++中结构体与类的区别(结构不能被继承,默认是public,在堆栈中创建,是值类型,而类是引用类型)good

    结构是一种用关键字struct声明的自定义数据类型.与类相似,也可以包含构造函数,常数,字段,方法,属性,索引器,运算符和嵌套类型等,不过,结构是值类型. 1.结构的构造函数和类的构造函数不同. a. ...

  2. 关于Emit中动态类型TypeBuilder创建类标记的一点思考

      利用TypeBuilder是可以动态创建一个类型,现在有个需求,动态生成一个dll,创建类型EmployeeEx,需要继承原dll里面的Employee类,并包含Employee类上的所有类标记. ...

  3. 【转载】 Java中String类型的两种创建方式

    本文转载自 https://www.cnblogs.com/fguozhu/articles/2661055.html Java中String是一个特殊的包装类数据有两种创建形式: String s ...

  4. Java归去来第4集:java实战之Eclipse中创建Maven类型的SSM项目

    一.前言 如果还不了解剧情,请返回第3集的剧情          Java归去来第3集:Eclipse中给动态模块升级 二.在Eclipse中创建Maven类型的SSM项目 2.1:SSM简介 SSM ...

  5. 在 QML 中创建 C++ 导入类型的实例

    在 QML 中创建 C++ 导入类型的实例 文件列表: Project1.pro QT += quick CONFIG += c++ CONFIG += declarative_debug CONFI ...

  6. 受检查异常要求try catch,new对象时,就会在堆中创建内存空间,创建的空间包括各个成员变量类型所占用的内存空间

    ,new对象时,就会在堆中创建内存空间,创建的空间包括各个成员变量类型所占用的内存空间

  7. 图像处理中创建CDib类时无法选择基类类型时怎么办

    图像处理中创建CDib类时无法选择基类类型时怎么办? 类的类型选择Generic Class 在下面的篮筐里输入CObject就行了

  8. In-Memory:在内存中创建临时表和表变量

    在Disk-Base数据库中,由于临时表和表变量的数据存储在tempdb中,如果系统频繁地创建和更新临时表和表变量,大量的IO操作集中在tempdb中,tempdb很可能成为系统性能的瓶颈.在SQL ...

  9. 详解Linux交互式shell脚本中创建对话框实例教程_linux服务器

    本教程我们通过实现来讲讲Linux交互式shell脚本中创建各种各样对话框,对话框在Linux中可以友好的提示操作者,感兴趣的朋友可以参考学习一下. 当你在终端环境下安装新的软件时,你可以经常看到信息 ...

随机推荐

  1. css div 不能贴边

    *{margin:0;padding:0} 在css 最前加上这句,取消所有内边距和外边距.

  2. hdu 1034 Candy Sharing Game

    Candy Sharing Game Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Other ...

  3. 射频识别技术漫谈(1)——概念、分类

    现代社会智能卡已经渗透到生活的方方面面,公交卡.考勤卡.身份证.手机卡等等数不胜数.    智能卡按使用时是否和读卡器接触可分为接触式智能卡和非接触式智能卡,接触式智能卡上有6-8个触点,使用时插在卡 ...

  4. javascript之函数篇

    1.我们都知道定义函数有两种方式:函数声明和函数表达式(其实还有Function构造函数方式,不推荐使用) 如: 声明方式:function sum(num1,num2){returm num1+nu ...

  5. JSP九大内置对象分析

    JSP九大内置对象分为三类: 1.输入输出对象:out对象.response对象.request对象 2.通信控制对象:pageContext对象.session对象.application对象 3. ...

  6. js 类似php中foreach的方法

    参考下面实例 <script>var arr =  {    'a' : '111111',    'b' : '222222',    'c' : '333333'};for(var k ...

  7. zoj 3820 Building Fire Stations 树的中心

    Building Fire Stations Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://acm.zju.edu.cn/onlinejudge ...

  8. SHGetSpecialFolderLocation

    uses shlobj;function GetDesktopFolder():string;var  pItem: PItemIDList;  temp: array[0..MAX_PATH] of ...

  9. 手动配置Ubuntu Linux系列3-缺省网关和主机名

    上一篇讲到[原创]手动配置Ubuntu Linux的DHCP客户端,这里再说一下配置静态IP地址的方法.   仍然是编辑 interfaces文件.   $ sudo vi /etc/network/ ...

  10. Opencv cvCircle函数

    cvCircle(CvArr* img, CvPoint center, int radius, CvScalar color, int thickness=1, int lineType=8, in ...