不确定是否有更优雅的方式来处理dotnet，但你总是可以在Windows上创建Batch *.bat文件（或Linux中的Bash脚本）并编写任何你想要的命令，如下所示：

dotnet build <your_main_project_name> 
dotnet publish <your_second_project_name> 
copy <path_to_second_bin> <path_to_target_bin>

当然，也有特殊的PowerShell脚本文件等，但总体思路是使用脚本。您可以查找指南或检查一些Batch commands和Bash commands。这可能是老式的，但总是工作的方式

您可以编写一个控制台程序，以便能够将程序集复制到主启动项目bin文件夹中，但不幸的是，这仍然使用PostBuild。
控制台程序如下：

public class Program
 {
     public static void Main(string[] args)
     {
         //string para1 = @"D:\word_code\Server\myProj\\bin,casereport,D:\Web_zy\Bin";// followed by source, dll file keywords, target directory
         string para1 =args[0];
         string[] ar = para1.Split(',', '|', ',');//source project bin path, keyword of mobile dll file, target server path
         Console.WriteLine("Source: " + ar[0]);
         Console.WriteLine("Target: " + ar[2]);
         var moveFile = new List<string>();
         if (!string.IsNullOrWhiteSpace(ar[0]) && !string.IsNullOrWhiteSpace(ar[1]))
         {
             var list=GetFiles(ar[0],"", true);
             moveFile = (from p in list
                     where Path.GetFileName(p).ToLower().Contains(ar[1].ToLower())
                     select p).ToList();
         }
         if (!string.IsNullOrWhiteSpace(ar[2]))
         {
             foreach (var item in moveFile)
             {
                 CopyFile(item, $@"{ar[2]}\{Path.GetFileName(item)}");
             }
         }
         Console.ForegroundColor = ConsoleColor.Green;
         Console.Write("[Success] Press any key to exit...");
         Console. ReadKey(true);
     }

     #region Find all files in a directory that contains subdirectories
     /// <summary>
     /// Get all files in the directory or the specified file type file address
     /// </summary>
     public static List<string> fileList = new List<string>();
     public static string[] GetFiles(string fullPath, string extName, bool isFullName = false)
     {
         try
         {
             fileList. Clear();
             DirectoryInfo dirs = new DirectoryInfo(fullPath); //Get the directory object of the path where the program is located
             DirectoryInfo[] dir = dirs.GetDirectories();//Get the folder object under the directory
             FileInfo[] file = dirs.GetFiles();//Get the file object under the directory
             int dircount = dir.Count();//Get the number of folder objects
             int filecount = file.Count();//Get the number of file objects

             // loop through folders
             for (int i = 0; i < dircount; i++)
             {
                 string pathNode = fullPath + "\\" + dir[i].Name;
                 GetMultiFile(pathNode, isFullName);
             }

             // loop through files
             for (int j = 0; j < filecount; j++)
             {
                 if (isFullName)
                 {
                     fileList.Add(file[j].FullName);
                 }
                 else
                 {
                     fileList.Add(file[j].Name);
                 }
             }

             return fileList. ToArray();
         }
         catch (Exception ex)
         {
             Console.WriteLine (ex.Message + "\r\nThe location of the error is: Form1.PaintTreeView()");
         }

         return null;
     }

     private static bool GetMultiFile(string path, bool isFullName = false)
     {
         if (Directory. Exists(path) == false)
         { return false; }

         DirectoryInfo dirs = new DirectoryInfo(path); //Get the directory object of the path where the program is located
         DirectoryInfo[] dir = dirs.GetDirectories();//Get the folder object under the directory
         FileInfo[] file = dirs.GetFiles();//Get the file object under the directory
         int dircount = dir.Count();//Get the number of folder objects
         int filecount = file.Count();//Get the number of file objects
         int sumcount = dircount + filecount;

         if (sumcount == 0)
         { return false; }

         // loop through folders
         for (int j = 0; j < dircount; j++)
         {
             string pathNodeB = path + "\\" + dir[j].Name;
             GetMultiFile(pathNodeB, isFullName);
         }

         // loop through files
         for (int j = 0; j < filecount; j++)
         {
             if (isFullName)
             {
                 fileList.Add(file[j].FullName);
             }
             else
             {
                 fileList.Add(file[j].Name);
             }
         }
         return true;
     }

     /// <summary>
     /// Copy the file multiple times for a large file true: the copy is successful false: the copy fails
     /// </summary>
     /// <param name="soucrePath">Original file path</param>
     /// <param name="targetPath">Copy target file path</param>
     /// <returns></returns>
     public static bool CopyFile(string sourcePath, string targetPath)
     {
         try
         {
             // read the copied file stream
             using (FileStream fsRead = new FileStream(soucrePath, FileMode. Open, FileAccess. Read))
             {
                 //write to file copy stream
                 using (FileStream fsWrite = new FileStream(targetPath, FileMode. OpenOrCreate, FileAccess. Write))
                 {
                     byte[] buffer = new byte[1024 * 1024 * 2]; // read 2M each time
                     while (true)//The file is large, read 2M each time
                     {
                         int n = fsRead.Read(buffer, 0, buffer.Count());//Data read each time n: is the actual data size read each time
                         //If n=0, it means that the read data is empty and has been read to the end, jump out of the loop
                         if (n == 0)
                         {
                             break;
                         }
                         //write each time the actual data size read
                         fsWrite.Write(buffer, 0, n);
                     }
                 }
             }
             return true;
         }
         catch (Exception ex)
         {
             return false;
         }
     }
     #endregion
 }