在 C# 中引用来自不同文件夹的类

Question

我有来自 2 个不同文件夹的 2 个程序，目前，我在 SectionA.cs 中有一个类（命名空间 SectionA，类名 Employee），我想重用 SectionB.cs（命名空间 SectionB）中的类中的一个方法，但是我不知道如何从 SectionB.cs 中引用一个类。我听说你必须使用using SectionA;，但它给了我这个错误

找不到类型或命名空间名称“SectionA”（您是否缺少 using 指令或程序集引用？）[SectionB]

下图为文件目录，请问如何引用SectionA.cs中的类在SectionB.cs中使用？提前谢谢你。

SectionA.cs

using System;
using System.IO;
using System.Collections.Generic;

namespace SectionA
{
    public delegate void generateDelegate(List<Employee> EmployeeList);
    public class Employee
    {
        public string Nric, FullName, Salutation, Designation, Department, MobileNo, HireType;
        public DateTime Start_Date;
        public double Salary, MonthlyPayout;

        public Employee(string Nric, string FullName, string Salutation, DateTime Start_Date, string Designation, string Department, string MobileNo, string HireType, double Salary)
        {
            this.Nric = Nric;
            this.FullName = FullName;
            this.Salutation = Salutation;
            this.Start_Date = Start_Date;
            this.Designation = Designation;
            this.Department = Department;
            this.MobileNo = MobileNo;
            this.Salary = Salary;
            this.MonthlyPayout = 0.0;
        }
        static public string CorpAdmin(List<Employee> EmployeeList)
        {
            string result = "";
            foreach (Employee employee in EmployeeList)
            {
                result += employee.FullName + "," + employee.Designation + "," + employee.Department + "\n";
            }
            return result;
        }
        static public string Procurement(List<Employee> EmployeeList)
        {
            string result = "";
            foreach (Employee employee in EmployeeList)
            {
                result += employee.Salutation + "," + employee.FullName + "," + employee.MobileNo + "," + employee.Designation + "," + employee.Department + "\n";
            }
            return result;
        }
        static public string IT(List<Employee> EmployeeList)
        {
            string result = "";
            foreach (Employee employee in EmployeeList)
            {
                result += employee.Nric + "," + employee.FullName + "," + employee.Start_Date + "," + employee.Department + "," + employee.MobileNo + "\n";
            }
            return result;
        }
        static public List<Employee> readHRMasterList()
        {
            List<Employee> EmployeeList = new List<Employee>();
            string direct = System.IO.Directory.GetCurrentDirectory();
            string path = "";
            string[] pathList = direct.Split("\\");
            for (int i = 0; i < pathList.Length - 1; i++) { path = path + pathList[i] + "\\"; }
            path += "HRMasterlist.txt";
            using (StreamReader sr = File.OpenText(path))
            {
                string s;
                while ((s = sr.ReadLine()) != null)
                {
                    string[] Emp = s.Split("|");
                    EmployeeList.Add(new Employee(Emp[0], Emp[1], Emp[2], Convert.ToDateTime(Emp[3]), Emp[4], Emp[5], Emp[6], Emp[7], Convert.ToDouble(Emp[8])));
                }
            }
            return EmployeeList;
        }
        static public void generateInfoForCorpAadmin(List<Employee> Employee_list)
        {
            string result = CorpAdmin(Employee_list);
            string path = @"CorporateAdmin.txt";
            string text = "";
            if (!File.Exists(path)) { using (StreamWriter sw = File.CreateText(path)) { } }
            using (StreamReader sr = File.OpenText(path))
            {
                string s;
                while ((s = sr.ReadLine()) != null)
                {
                    if (s != "") { text = text + s + "\n"; }
                }
            }
            using (StreamWriter sw = File.CreateText(path))
            {
                sw.WriteLine(text + result);
            }
        }
        static public void generateInfoForProcurement(List<Employee> Employee_list)
        {
            string result = Procurement(Employee_list);
            string path = @"Procurement.txt";
            string text = "";
            if (!File.Exists(path)) { using (StreamWriter sw = File.CreateText(path)) { } }
            using (StreamReader sr = File.OpenText(path))
            {
                string s;
                while ((s = sr.ReadLine()) != null)
                {
                    if (s != "") { text = text + s + "\n"; }
                }
            }
            using (StreamWriter sw = File.CreateText(path))
            {
                sw.WriteLine(text + result);
            }
        }
        static public void generateInfoForITDepartment(List<Employee> Employee_list)
        {
            string result = IT(Employee_list);
            string path = @"ITDepartment.txt";
            string text = "";
            if (!File.Exists(path)) { using (StreamWriter sw = File.CreateText(path)) { } }
            using (StreamReader sr = File.OpenText(path))
            {
                string s;
                while ((s = sr.ReadLine()) != null)
                {
                    if (s != "") { text = text + s + "\n"; }
                }
            }
            using (StreamWriter sw = File.CreateText(path))
            {
                sw.WriteLine(text + result);
            }
        }

        static void Main(string[] args)
        {
            List<Employee> EmployeeList = new List<Employee>();
            EmployeeList = readHRMasterList();
            generateDelegate del1 = generateInfoForCorpAadmin;
            generateDelegate del2 = generateInfoForProcurement;
            generateDelegate del3 = generateInfoForITDepartment;
            generateDelegate del = del1 + del2 + del3;
            del(EmployeeList);
        }
    }
}

SectionB.cs

using System;
using SectionA;
namespace SectionB
{
    class SectionB
    {
        static void Main(string[] args)
        {
        }
    }
}

Answer 1

您需要将SectionB 项目的引用添加到SectionA 项目，然后using 应该可以工作。

Answer 2

您可以尝试打开项目的 SetrionB.csproj 文件并添加项目引用，如下所示：

<ItemGroup>
    <ProjectReference Include = "../SectionA.csproj" />
</ItemGroup>

之后你就可以在你的代码中使用它了

using ....
.....

Answer 3

如果你在 Visual Studio 中打开它，你可以右键单击 SectionB -> References -> Add Reference 并添加选择 SectionA 的引用。