如何从Delphi中调用C#控制台程序并获取返回值？

方案1：通过控制台标准输出传递返回值（适合返回字符串等任意文本内容） #

C#端修改代码 #

直接把要返回的内容通过Console.WriteLine输出到标准输出流即可：

using System;

namespace Test
{
    class Program
    {
        static int Main()
        {
            // 要返回给Delphi的内容
            Console.WriteLine("hello world");
            // 退出码，0表示执行正常，可自定义其他状态码标识执行结果
            return 0;
        }
    }
}

编译后记录C#程序的exe路径，比如C:\test\TestCSharp.exe。

Delphi端修改代码 #

通过创建子进程捕获C#程序的标准输出内容，直接用Windows API实现即可：

program Project2;

{$APPTYPE CONSOLE}

{$R *.res}

uses
  System.SysUtils, Winapi.Windows, Winapi.ShellAPI;

function GetConsoleOutput(const CommandLine: string; out Output: string): Integer;
var
  Security: TSecurityAttributes;
  ReadPipe, WritePipe: THandle;
  Startup: TStartupInfo;
  ProcessInfo: TProcessInformation;
  Buffer: array[0..4095] of AnsiChar;
  BytesRead: DWORD;
begin
  Result := -1;
  Output := '';
  ZeroMemory(@Security, SizeOf(Security));
  Security.nLength := SizeOf(Security);
  Security.bInheritHandle := True;
  Security.lpSecurityDescriptor := nil;

  if not CreatePipe(ReadPipe, WritePipe, @Security, 0) then Exit;
  try
    ZeroMemory(@Startup, SizeOf(Startup));
    Startup.cb := SizeOf(Startup);
    Startup.dwFlags := STARTF_USESHOWWINDOW or STARTF_USESTDHANDLES;
    Startup.wShowWindow := SW_HIDE;
    Startup.hStdOutput := WritePipe;
    Startup.hStdError := WritePipe;

    if CreateProcess(nil, PChar(CommandLine), nil, nil, True, CREATE_NEW_CONSOLE or NORMAL_PRIORITY_CLASS, nil, nil, Startup, ProcessInfo) then
    begin
      CloseHandle(WritePipe);
      WritePipe := 0;
      WaitForSingleObject(ProcessInfo.hProcess, INFINITE);
      GetExitCodeProcess(ProcessInfo.hProcess, DWORD(Result));
      while ReadFile(ReadPipe, Buffer[0], SizeOf(Buffer), BytesRead, nil) and (BytesRead > 0) do
      begin
        Output := Output + string(Copy(Buffer, 0, BytesRead));
      end;
      CloseHandle(ProcessInfo.hThread);
      CloseHandle(ProcessInfo.hProcess);
    end;
  finally
    if WritePipe <> 0 then CloseHandle(WritePipe);
    CloseHandle(ReadPipe);
  end;
end;

begin
  try
    var CSharpExePath := 'C:\test\TestCSharp.exe'; // 替换成你自己的C#程序实际路径
    var ReturnValue: string;
    var ExitCode := GetConsoleOutput(CSharpExePath, ReturnValue);
    Writeln('C#程序退出码：', ExitCode);
    Writeln('C#返回的内容：', Trim(ReturnValue));
    Readln; // 暂停查看结果
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
end.

运行Delphi程序就能直接拿到C#返回的hello world字符串并打印。

方案2：通过进程退出码传递返回值（仅适合返回整数类型结果） #

如果只需要返回整数状态，不需要字符串内容，可以直接用进程退出码传递，实现更简单：

C#端代码 #

using System;

namespace Test
{
    class Program
    {
        static int Main()
        {
            // 直接返回整数，范围0-255最佳，避免兼容问题
            return 123;
        }
    }
}

Delphi端代码 #

program Project2;

{$APPTYPE CONSOLE}

{$R *.res}

uses
  System.SysUtils, Winapi.Windows, Winapi.ShellAPI;

function GetProcessExitCode(const ExePath: string): Integer;
var
  ShExecInfo: TShellExecuteInfo;
begin
  Result := -1;
  ZeroMemory(@ShExecInfo, SizeOf(ShExecInfo));
  ShExecInfo.cbSize := SizeOf(ShExecInfo);
  ShExecInfo.fMask := SEE_MASK_NOCLOSEPROCESS;
  ShExecInfo.hwnd := 0;
  ShExecInfo.lpVerb := 'open';
  ShExecInfo.lpFile := PChar(ExePath);
  ShExecInfo.lpParameters := nil;
  ShExecInfo.lpDirectory := nil;
  ShExecInfo.nShow := SW_HIDE;

  if ShellExecuteEx(@ShExecInfo) then
  begin
    WaitForSingleObject(ShExecInfo.hProcess, INFINITE);
    GetExitCodeProcess(ShExecInfo.hProcess, DWORD(Result));
    CloseHandle(ShExecInfo.hProcess);
  end;
end;

begin
  try
    var CSharpExePath := 'C:\test\TestCSharp.exe'; // 替换成你自己的C#程序实际路径
    var ExitCode := GetProcessExitCode(CSharpExePath);
    Writeln('C#程序返回的退出码：', ExitCode);
    Readln;
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
end.

内容的提问来源于stack exchange，提问作者Maik Hasler