C#入門學習之屬性和方法

標籤：

一 總結

1 方法分為靜態方法和非靜態方法，靜態方法不對特定的執行個體進行操作，且不允許引用this，非靜態方法是對類的某個特定的執行個體進行操作，且可以用this來訪改方法

例子一 靜態方法：

public static int add(int x,int y)

{

return x+y;

}

static void Main(string[] args)

{

Console.WriteLine(Program.add(3,4));

}

例子二 非靜態方法

public int add(int x,int y)

{

return x+y;

}

static void Main(string[] args)

{

Program program=new Program();   //執行個體化對象

Console.WriteLine(Program.add(3,4));

}

2 params關鍵字可以指定採用數目可變的參數的方法參數

註：一個函數中只能一個參數帶params關鍵字；
·帶params關鍵字的參數必須是最後一個參數；
·帶params關鍵字的參數類型必須是一維數組； 

二  執行個體

1 求數組中最大元素值的方法

         static void Main(string[] args)

        {

            int[] myArray = {1,5,3,7,8,22,21,33,35,99,26 };

            int maxVal = MaxValue(myArray);

            Console.WriteLine("The maximum value in myArray is {0}",maxVal);

            Console.ReadKey();

        }

        static int MaxValue(int[] intArray)

        {

            int maxVal =intArray[0];

            for (int i = 1; i < intArray.Length; i++)

            {

                if (intArray[i] > maxVal)

                {

                    maxVal=intArray[i];

                }          

            }

            return maxVal;

        }

2 求數組元素和的方法

  static int SumVals(params int[] vals)  //關鍵字params

        {

            int sum = 0;

            foreach (int val in vals)

            {

                sum += val;

            }

            return sum;

        }

        static void Main(string[] args)

        {

            int sum = SumVals(1, 2, 3, 4, 5);

            Console.WriteLine("The sum={0}", sum);

            Console.ReadKey();

        }    }

3 物件導向和方法運用的小程式

using System;

    class Address

    {

        public string name;

        public string address;

    }

    class Methodparams

    {

        public static void Main()

        {

            string myChoice;

            Methodparams mp = new Methodparams();

            do

            {

                myChoice = mp.getchoice();

                mp.makeDecision(myChoice);

                Console.Write("Press any key to continue...");

                Console.ReadLine();

               Console.WriteLine();

            } while (myChoice != "Q" && myChoice != "q");

        }

        string getchoice()

        {

            string mychoice;

            Console.WriteLine("My Address Book\n");

            Console.WriteLine("A-Add New Address");

            Console.WriteLine("D-Delete Address");

            Console.WriteLine("M-Modify Address");

            Console.WriteLine("V-View Addresses");

            Console.WriteLine("Q-Quit\n");

            Console.WriteLine("Choice(A,D,M,V,Q)");

            mychoice = Console.ReadLine();

            return mychoice;

        }

        void makeDecision(string myChoice)

        {

            Address addr = new Address();

            switch (myChoice)

            {

                case "A":

                case "a":

                    addr.name = "Joe";

                    addr.address = "C# station";

                    this.addAddress(ref addr);

                    break;

                case "D":

                case"d":

                    addr.name="Robert";

                    this.deleteAddress(addr.name);

                    break;

                case "M":

                case "m":

                    addr.name="Matt";

                    this.modifyAddress(out addr);

                    Console.WriteLine("Name is now {0}",addr.name);

                    break;

                case "V":

                case "v":

                    this.viewAddress("Cheryl","Joe","Matt","Robert");

                    break;

                case "Q":

                case "q":

                    Console.WriteLine("Bye");

                    break;

 

            }

        }

        void addAddress(ref Address addr)

        {

            Console.WriteLine("Name:{0},Address:{1} added.",addr.name,addr.address);

        }

        void deleteAddress(string name)

        {

            Console.WriteLine("You wish to delete {0}‘s address.",name);

        }

        void modifyAddress(out Address addr)

        {

            addr = new Address();

            addr.name = "Joe";

            addr.address = "C# Station";

        }

        void viewAddress(params string[] names)

        {

            foreach (string name in names)

            {

                Console.WriteLine("Name:{0}",name);

            }

        }

    }

 

C#入門學習之屬性和方法