关于Property赋值

赋值1：

using System;

class ComplexNumber
{
     public double Real { get; set; }
     public double Imaginary { get; set; }
 
     public override string ToString()
     {
          return String.Format("{0}{1}{2}i", 
              Real, 
              Imaginary >= 0 ? "+" : "-", 
              Math.Abs(Imaginary));
      }
}

class CompareComplexNumbers
{
     public static void Main()
     {
          ComplexNumber a = new ComplexNumber() //初始化赋值
              { Real = 4.5D, Imaginary = 8.4D };
          ComplexNumber b = new ComplexNumber() 
              { Real = 6.3D, Imaginary = -2.3D };
          ComplexNumber c = new ComplexNumber() 
              { Real = 4.5D, Imaginary = 8.4D };
  
          Console.WriteLine("{0} equals {1}: {2}", 
              a, b, CompareTwoComplexNumbers(a, b));
          Console.WriteLine("{0} equals {1}: {2}", 
              b, c, CompareTwoComplexNumbers(b, c));
          Console.WriteLine("{0} equals {1}: {2}", 
              a, c, CompareTwoComplexNumbers(a, c));
      }
 
     static bool CompareTwoComplexNumbers(ComplexNumber A, ComplexNumber B)
     {
          // This returns true only if the real parts and the imaginary parts are equal
          return ((A.Real == B.Real) && (A.Imaginary == B.Imaginary));
      }
}

赋值2：property的setter为private屏蔽外界，赋值可通过constructer，property的setter没有写代表只读，所以赋值需要从filed

/// <summary>
/// A guy with a name, age and a wallet full of bucks
/// </summary>
class Guy
{
     /// <summary>
     /// Read-only backing field for the Name property
     /// </summary>
     private readonly string name;
 
     /// <summary>
     /// The name of the guy
     /// </summary>
     public string Name { get { return name; } }
 
     /// <summary>
     /// Read-only backing field for the Name property
     /// </summary>
     private readonly int age;
 
     /// <summary>
     /// The guy's age
     /// </summary>
     public int Age { get { return age; } }
 
     /// <summary>
     /// The number of bucks the guy has
     /// </summary>
     public int Cash { get; private set; }
 
     /// <summary>
     /// The constructor sets the name, age and cash
     /// </summary>
     /// <param name="name">The name of the guy</param>
     /// <param name="age">The guy's age</param>
     /// <param name="cash">The amount of cash the guy starts with</param>
     public Guy(string name, int age, int cash) {
          this.name = name;
          this.age = age;
          Cash = cash;
      }
 
     public override string ToString() {
          return String.Format("{0} is {1} years old and has {2} bucks", Name, Age, Cash);
      }
 
     /// <summary>
     /// Give cash from my wallet
     /// </summary>
     /// <param name="amount">The amount of cash to give</param>
     /// <returns>The amount of cash I gave, or 0 if I don't have enough cash</returns>
     public int GiveCash(int amount) {
          if (amount <= Cash && amount > 0)
          {
               Cash -= amount;
               return amount;
           }
          else
          {
               return 0;
           }
      }
 
     /// <summary>
     /// Receive some cash into my wallet
     /// </summary>
     /// <param name="amount">Amount to receive</param>
     /// <returns>The amount of cash received, or 0 if no cash was received</returns>
     public int ReceiveCash(int amount) {
          if (amount > 0)
          {
               if (amount > 0)
               {
                    Cash += amount;
                    return amount;
                }
               Console.WriteLine("{0} says: {1} isn't an amount I'll take", Name, amount);
           }
          return 0;
      }
}