class SampleCollection<T>
{// 声明一个数组来存储数据元素。private T[] arr = new T[100];// 定义索引器,它允许客户机代码 　　/ /类实例上使用[]符号本身。 　　/ /下面的代码主要(参见第2行。)         public T this[int i]{get{//这个索引器非常简单,仅仅返回或设置 　　//数组从内部相应的元素。return arr[i];}set{arr[i] = value;}}
}//program类显示了客户端代码使用索引器。
class Program
{static void Main(string[] args){// 声明SampleCollection类型的一个实例。SampleCollection<string> stringCollection = new SampleCollection<string>();// 使用[]符号的类型。stringCollection[0] = "Hello, World";System.Console.WriteLine(stringCollection[0]);}
}                

class Test
{static void Main(){int mInt;object obj=mInt;//装箱int myInt=(int) obj;//拆箱
          }
}    

class TestRef
{int a=5;myMethod(ref a);//use func by ref
       .........void myMethod(ref int a){//function block
        }
}

class TestOut
{int val;getNodeValue(val);..........bool getNodeValue(out int val){val = value;return true;}    

class TestArray{void func(param int []array){print(array.length);}func(1);//输出1
func();//输出0
func(7,9,4);//输出3
func(new int[]array {4,6,7,3,5});//输出5int []array2=new int[]{4,5,6,1,2,3};func(array2);//输出6

}

class test1{}
class test2{}
class test3: test2{}class isTest
{test1 t1;test2 t2;static void Test(object obj){if(obj is t1){print("obj is test1 classes");t1 = (test1)obj;}else if(obj is t2){print("obj is test2 classes);t2 = (test2)obj;}else{print("obj not is test1 and test2");}    }static void Main(){test1 T1=new test1();test2 T2 = new test2();test3 T3 = new test3();test(T1);test(T2);test(T3);test("my test content");}
}

namespace MyFirstApp
{class Base{public override string ToString(){return "base";}}class Device : Base{public delegate void GetVisiter(string name);}class Program{        static int Main(){Device de = new Device();Base b = de as Base;if(de != null){System.Console.WriteLine(de.ToString());}return 0;}}
}

expression as type

expression is type ? (type)expression : (type)null

//interface
interface Equatable<T>
{bool Equals(T obj);//只能写出函数声明
}//
public class TestEquals : Equatable<TestEquatable>
{public string Make { get; set; }public string Module { get; set; }public string Year { get; set; }public bool Equals(TestEquals te)//实现基类当中的Equals函数
    {if(this.Make==te.Make &&this.Module==te.Module &&this.Year==te.Year){return true;}else{return flase}
}