Atributes:

//can add metadata in program, It store with the program

//using ILDasm to check atributes

//usage

[CodeReviewAttribute("08/08/2005", "Allan Zhang",

Comment = "That is a Attribute test")]

class Employee {}

//define target and atr

[AttributeUsage(AttributeTargets.Class |

AttributeTargets.Constructor |

AttributeTargets.Interface |

AttributeTargets.Method |

AttributeTargets.Field |

AttributeTargets.Property,

AllowMultiple=true)]

class CodeReviewAtrribute : System.Attribute

{

private string reviewDate;

private string reviewerName;

private string reviewComments;

...

}

Reflections: //look the metadata in program, discory, late binding

//Display attribute in Code

System.Reflection.MemberInfo inf = typeof(Employee);

object[] atributes = inf.GetCustomAttributes(false);

foreach (object attribute in attributes)

{

CodeReviewAttribute attr = (CodeReviewAttribute) attribute;

Console.WriteLine("This is code was reviewed on {0} by {1} \n Comments {2}",

attr.date,

attr.name,

attr.comment )

}

//Discovery

Assembly asm = Assembly.Load("Mscorlib.dll");

Type[] types = asm.GetTypes();

foreach(Type type in types)

{

Console.WriteLine("Type is{0}, type);

Console.WriteLine("\n{0} types found." types.Length);

}

//LateBinding

Type mathType =Type.GetType("System.Math");

object obj = Activator.CreaterInstance(mathType);

Type[] parameterTypes = new Type[2];

parameterTypes[0] = Type.GetType("System.Double");

parameterTypes[1] = Type.GetType("System.Double");

MethodInfo powInfo = mathType.GetMethod("Pow", parameterTypes);

object[] parameters = new object[2];

parameters[0] = 5;

parameters[1] = 3;

object returnValue = powInfo.Invoke(obj, parameters);

Console.WriteLine("5 to the 3rd power is {0}, returnValue);

Thread:

//Create Implicit Threads

using System.Threading

Thread threadOne = new Thread(new ThreadStart(Countup));

Thread threadTwo = new Thread(new ThreadStart(Countup));

threadOne.Name = "Thread One";

threadTwo.Name = "Thread two";

threadOne.Start();

threadTwo.Start();

//Joining & killing Threads

//join two threads in current threa

threadOne.start();

threadTwo.Start();

threadOne.Join();

threadTwo.Join();

//this will print, after two above two threads ends

Console.WriteLine("The other threads done");

//sleep(millisenconds)

threadOne.sleep(1);

threadOne.Abort();

Synchronization:

//1. no conflict between threads

interlocked.Increment(ref synchValue);

//2. lock method, this will block other thread when it enter into it

lock(this)

{

int temp = synchValue;

temp++;

Thread.Sleep(2);

synchValue = temp;

synchValue = temp;

Console.WriteLine("{0} Count up: {1}",

Thread.CurrentThread.Name,

synchValue);

}