使用反射查詢類的方法和字段以及使用IS運算符號類轉換和AS運算符

使用反射查詢類的方法和字段
using System;
using System.Reflection;

namespace Refrect
{
 /// <summary>
 /// Class1 的摘要說明。
 /// </summary>
 class cleQueryMyClass
 {
  /// <summary>
  /// 應用程序的主入口點。
  /// </summary>
  [STAThread]
  static void Main(string[] args)
  {
   Type t = typeof(Demo);

   MethodInfo[] Methods = t.GetMethods();
   System.Console.Write("Methods");
   foreach(MethodInfo Method in Methods)
   {
    System.Console.Write("{0}/n",Method.Name);
   }

   System.Console.Write("Members");
   MemberInfo[] Members = t.GetMembers();
   foreach(MemberInfo Member in Members)
   {
    System.Console.Write("{0}/n",Member.Name);
   }

   System.Console.Write("Fields");
   FieldInfo[] Fields = t.GetFields();
   foreach(FieldInfo Field in Fields)
   {
    System.Console.Write("{0}/n",Field.Name);
   } 
  }
 }
 class Demo
 {
  public int MemberOne = 1 ;
  public int MemberTwo = 2;
  public int MemberThree = 3 ;
  private int MemberFour = 4 ;
  private int MebmerFive = 5;
  
  public int MethodOne()
  {
   return MemberOne + MemberTwo;
  }
  public int MethodTwo()
  {
   return MemberThree + MemberFour;
  }

  public int MethodThree()
  {
   return MebmerFive;
  }
 }
}

利用反射動態調用方法
using System;
using System.Reflection;

namespace Refrect
{
    /// <summary>
    /// Class1 的摘要說明。
    /// </summary>
    class UsingInvoke
    {
        /// <summary>
        /// 應用程序的主入口點。
        /// </summary>
        [STAThread]
        static void Main(string[] args)
        {
            object myObject = null;
           
            // typeof創建一個string類的type類型對象myType
            Type myType = typeof(string);

            //調用其GetConstructor方法 取得一個包含所有String類定義的構造函數版本 myConsts包含了所有的構造函數版本
            ConstructorInfo[] myConsts = myType.GetConstructors();

            foreach (ConstructorInfo myConst in myConsts)
            {
                //取得版本構造函數需要的參數
                ParameterInfo[] myPI = myConst.GetParameters();
                if (myPI.Length == 2 && myPI[0].ParameterType.Name == "Char")
                {
                    object[] objPara ={ 'S', 5 };
                    // 條件成立 調用 ConstructorInfo的Invoke方法
                    myObject = myConst.Invoke(objPara);
                    Console.WriteLine(myObject.ToString());
                }
            }

            // 取得包含所有方法的數組對象myMIS
            MethodInfo[] myMIS = myType.GetMethods();
            foreach(MethodInfo myMI  in myMIS)
            {
                ParameterInfo[] myPara = myMI.GetParameters();
                if(myMI.Name=="ToLower"&&myPara.Length==0)
                {
                    Console.WriteLine(myMI.Invoke(myObject,null));
                }
            }

            Console.ReadLine();
        }
    }
}

使用IS運算符號
using System;

namespace UserIs
{
 /// <summary>
 /// clsIsOperator 的摘要說明。
 /// </summary>
 class clsIsOperator
 {
  /// <summary>
  /// 應用程序的主入口點。
  /// </summary>
  [STAThread]
  static void Main(string[] args)
  {
   clsTonePhone  Cellular = new clsTonePhone("555-1212");
   clsRotaryPhone GrandmasPhone = new clsRotaryPhone("555-5555");
   Cellular.Dial("800-555-1212");
   GrandmasPhone.Dial("800-555-1212");

   System.Console.Write("/n/n About to Create a Polymorphic phone/n");
   clsPhone Phone = Cellular;
   Phone.Dial("800-555-1212");

   if (Phone is clsTonePhone)
   {
    System.Console.Write("The Object is a tone phone/n");
   }

   Phone = GrandmasPhone;
   Phone.Dial("800-555-1212");

   if ( Phone is clsRotaryPhone)
   {
    System.Console.Write("The Object is a rotary phone/n");
   }
  }
 }
 class clsPhone
 {
  protected string Number;
  public clsPhone(string number)
  {
   Number = number;
  }
  public virtual void Dial(string NumberToCall)
  {
   System.Console.Write("Beep,Beep: Tone Dial");
   System.Console.Write("Calling{0}/n",NumberToCall);
  }
 }
 class clsRotaryPhone : clsPhone
 {
  public clsRotaryPhone(string number) : base(number){}
  
  public override void Dial(string NumberToCall)
     {
    System.Console.Write("In Rotary Dial,Calling {0}",NumberToCall);
     }
 }
 class clsTonePhone : clsPhone
 {
  public clsTonePhone(string number) : base(number){}
 } 
}
 
類轉換和AS運算符

using System;

namespace UserIs
{
 /// <summary>
 /// clsIsOperator 的摘要說明。
 /// </summary>
 class clsIsOperator
 {
  /// <summary>
  /// 應用程序的主入口點。
  /// </summary>
  [STAThread]
  static void Main(string[] args)
  {

   clsPhone  BasePhone = new clsPhone("555-1212");
   clsRotaryPhone DerivedPhone = new clsRotaryPhone("555-5555");

   DerivedPhone = BasePhone as clsRotaryPhone;
   
   if ( DerivedPhone == null )
   {
    System.Console.Write("DerivedPhone is Null/n");
   }
   else
   {
    System.Console.Write("BasePhone is downcast/n");
   }

   try
   {
    DerivedPhone = (clsRotaryPhone)BasePhone;
   }
   catch(System.Exception ex)
   {
    System.Console.Write("Invalid cast exception caught/n");
   }

   BasePhone = DerivedPhone as clsPhone;
   if ( BasePhone == null )
   {
    System.Console.Write("BasePhone is Null/n");
   }
   else
   {
    System.Console.Write("Base Phone has been upcate/n");
   }

   try
   {
    BasePhone = (clsPhone)DerivedPhone;
    System.Console.Write("DerivedPhone again upcast/n");
   }
   catch(System.Exception ex)
   {
    System.Console.Write("Invalid cast exception caught/n");
   }
  }
 }
 class clsPhone
 {
  protected string Number;
  public clsPhone(string number)
  {
   Number = number;
  }
  public virtual void Dial(string NumberToCall)
  {
   System.Console.Write("Beep,Beep: Tone Dial");
   System.Console.Write("Calling{0}/n",NumberToCall);
  }
 }
 class clsRotaryPhone : clsPhone
 {
  public clsRotaryPhone(string number) : base(number){}
  
  public override void Dial(string NumberToCall)
     {
    System.Console.Write("In Rotary Dial,Calling {0}",NumberToCall);
     }
 }
}