錯誤CS0563（一個二進制運算符的參數必須是包含類型）

Question

我的源代碼（下面）正在產生錯誤CS0563，因爲這兩個參數在我CombinedJobs操作者+（見「//步驟5：... 「在源代碼中）被列爲作業（而不是int，double等）。我如何更改此代碼以消除此錯誤？此代碼是爲了響應下面列出的任務。

分配：

「。設計一個招聘類哈羅德的家庭服務類包含四個數據字段，工作 描述（例如，‘洗窗’），時間以小時來完成作業（ 例如，3.5），每小時的速度收取作業（例如，$ 25.00），總費用 作業（時薪次小時）。包括屬性來獲取和設置每個字段除了 總費用 - 即場將只讀，並且其值在每個時間要麼 每小時費用或小時被設定數來計算。過載+運算，使得兩個工作 可以加入。在S兩份工作的UM是含有 原職位的描述（用「和」加盟），時間以小時爲原始作業的總和， 平均原始作業時薪的新工作。寫一個Main（）函數， 演示所有方法都能正常工作。將文件另存爲DemoJobs.cs「

來自：微軟的Visual C＃®2008年，介紹了面向對象程序設計，3E，喬伊斯·法雷爾

源代碼：

using System; 

//Step 1: Creating the Job class and designating its fields 

    public class Job 

    { 

     private string jobDescription; 

     private int jobTotalTime; 

     private double jobRate; 

     private double jobTotalFee; 


//Step 2: Using the 'this' object will allow me to designate values for 

//"this" instantiation of an object later in the program 

     public string JobDescription 
     { 
     get 
     { 
      return this.jobDescription; 
     } 
     set 
     { 
      this.jobDescription = value; 
     } 
     } 

     public int JobTotalTime 
     { 
     get 
     { 
      return this.jobTotalTime; 
     } 
     set 
     { 
      this.jobTotalTime = value; 
     } 
     } 

    public double JobRate 
     { 
     get 
     { 
      return this.jobRate; 
     } 
     set 
     { 
      this.jobRate = value; 
     } 
     }  

    public double JobTotalFee 
     { 
     get 
     { 
      return this.jobTotalFee; 
     } 
     set 
     { 
      this.jobTotalFee = this.JobRate * this.JobTotalTime; 
     } 
     } 

//Step 3: Creating a method will allow me to display the different jobs 

//with their descriptions and other variable fields later in the program 

    public void JobMessage() 

    { 

     Console.WriteLine("Job description: {0} /nTotal time needed to complete the job: {1} hours /nHourly fee: ${2} /nTotal fee for the job is: ${3}", this.JobDescription, this.JobTotalTime, this.JobRate, this.JobTotalFee); 

    } 


} 

//Step 4: Creating two instantiations of the Job Class 

public class CreateTwoJobs 

{ 

    public static void Main() 

    { 

    Job jobA = new Job(); 

    Job jobB = new Job(); 


    jobA.JobDescription = "washing windows"; 

    jobA.JobTotalTime = 5; 

    jobA.JobRate = 25.00; 


    jobB.JobDescription = "walking dogs"; 

    jobB.JobTotalTime = 10; 

    jobB.JobRate = 11.00; 


    jobA.JobMessage(); 

    jobB.JobMessage(); 

    } 

} 


//Step 5: Creating a third instantiation of the Job Class that is a combination 

//of the first two instantiations using the overloaded + operator 


public class CombinedJobs 

{ 

    public CombinedJobs(string jobDescription, int jobTotalTime, double jobRate, double jobTotalFee) 

    { 

    JobDescription = jobDescription; 

    JobTotalTime = jobTotalTime; 

    JobRate = jobRate; 

    JobTotalFee = jobTotalFee; 

    } 


    public static CombinedJobs operator+(Job jobA, Job jobB) 

    { 

    string newDescription = jobA.JobDescription + " and " + jobB.JobDescription; 

    int newTotalTime = jobA.JobTotalTime + jobB.JobTotalTime; 

    double newJobRate = (jobA.JobRate + jobB.JobRate)/2; 

    double newTotalFee = newJobRate * newTotalTime 

    } 


    public void CombinedJobMessage() 

    { 

     Console.WriteLine("Job description: {0} /nTotal time needed to complete the job: {1} hours /nHourly fee: ${2} /nTotal fee for the job is: ${3}", newDescription, newTotalTime, newJobRate, newTotalTime); 

    } 


    public static void Main() 

    { 

     CombinedJobMessage(); 

    } 

}  

Answer 1

的operator+方法必須在其參數之一的類中，因爲在您的情況下，兩個參數都是Job，該方法必須位於Job類中，不能在CombinedJobs之內。另外，您聲明運營商返回CombinedJobs，這意味着您必須實際返回它。這不會導致您正在描述的錯誤，但會導致另一個編譯錯誤。