如何修改Delphi的CaptureConsoleOutput过程以正确捕获Unicode控制台输出？

问题根源 #

程序无法正确显示Unicode字符的核心原因：

1. 默认调用cmd.exe时使用ANSI编码输出，tree命令的分支符号属于OEM字符集，中文/俄文等非英文字符会因编码不匹配乱码
2. 原CaptureConsoleOutput过程使用ANSI版本WinAPI读取管道，未全程以宽字符处理数据

修改后的实现（线程安全版） #

为实时且正确显示Unicode输出，我们使用Unicode版本WinAPI、添加cmd /U参数强制Unicode输出，并通过线程避免UI阻塞：

type
  TConsoleCaptureThread = class(TThread)
  private
    FCommand: string;
    FTargetMemo: TMemo;
    procedure AppendToMemo(const OutputLine: string);
  protected
    procedure Execute; override;
  public
    constructor Create(const CmdLine: string; TargetMemo: TMemo);
  end;

constructor TConsoleCaptureThread.Create(const CmdLine: string; TargetMemo: TMemo);
begin
  inherited Create(True);
  FCommand := CmdLine;
  FTargetMemo := TargetMemo;
  FreeOnTerminate := True;
end;

procedure TConsoleCaptureThread.AppendToMemo(const OutputLine: string);
begin
  FTargetMemo.Lines.Add(OutputLine);
end;

procedure TConsoleCaptureThread.Execute;
var
  StartupInfo: TStartupInfoW;
  ProcessInfo: TProcessInformation;
  PipeRead, PipeWrite: THandle;
  SecurityAttr: TSecurityAttributes;
  BytesRead: DWORD;
  WideBuffer: array[0..4095] of WideChar;
  OutputStr: UnicodeString;
begin
  // 配置管道安全属性，允许句柄继承
  FillChar(SecurityAttr, SizeOf(SecurityAttr), 0);
  SecurityAttr.nLength := SizeOf(SecurityAttr);
  SecurityAttr.bInheritHandle := True;
  SecurityAttr.lpSecurityDescriptor := nil;

  // 创建匿名管道用于捕获输出
  if not CreatePipe(PipeRead, PipeWrite, @SecurityAttr, 0) then
    Exit;

  try
    // 初始化进程启动信息，指定标准输出为管道
    FillChar(StartupInfo, SizeOf(StartupInfo), 0);
    StartupInfo.cb := SizeOf(StartupInfo);
    StartupInfo.dwFlags := STARTF_USESTDHANDLES or STARTF_USESHOWWINDOW;
    StartupInfo.hStdOutput := PipeWrite;
    StartupInfo.hStdError := PipeWrite; // 同时捕获错误输出
    StartupInfo.wShowWindow := SW_HIDE; // 隐藏cmd窗口

    // 启动cmd，使用/U参数强制Unicode输出，指定Unicode环境
    if not CreateProcessW(nil, PWideChar('cmd.exe /U /C ' + FCommand), nil, nil, True,
      CREATE_UNICODE_ENVIRONMENT or NORMAL_PRIORITY_CLASS, nil, nil, StartupInfo, ProcessInfo) then
      Exit;

    try
      // 关闭管道写端，确保进程输出完毕后管道触发EOF
      CloseHandle(PipeWrite);

      // 循环读取管道内容，直到进程结束或线程终止
      while not Terminated and ReadFile(PipeRead, WideBuffer, SizeOf(WideBuffer), BytesRead, nil) and (BytesRead > 0) do
      begin
        // 将读取的宽字符转换为Delphi UnicodeString
        SetLength(OutputStr, BytesRead div SizeOf(WideChar));
        Move(WideBuffer, OutputStr[1], BytesRead);
        // 同步更新UI，避免跨线程访问控件错误
        Synchronize(procedure
        begin
          AppendToMemo(OutputStr);
        end);
      end;
    finally
      // 释放进程和线程句柄
      CloseHandle(ProcessInfo.hProcess);
      CloseHandle(ProcessInfo.hThread);
    end;
  finally
    // 释放管道读端句柄
    CloseHandle(PipeRead);
  end;
end;

// 调用示例（按钮点击事件）
procedure TForm1.RunCommandBtnClick(Sender: TObject);
begin
  CommandMemo.Clear;
  // 示例：捕获tree命令输出
  TConsoleCaptureThread.Create('tree .', CommandMemo).Start;
end;

关键修改说明 #

• cmd /U参数：强制cmd以UTF-16 Unicode格式输出内容，确保tree分支符号、中文/俄文等字符编码正确
• Unicode版本WinAPI：全程使用CreatePipeW、CreateProcessW、TStartupInfoW等宽字符API，避免ANSI转码丢失数据
• 线程安全更新UI：通过Synchronize方法跨线程更新Memo控件，避免UI阻塞和控件访问错误
• 正确的句柄管理：及时关闭不需要的管道和进程句柄，防止系统资源泄漏

内容的提问来源于stack exchange，提问作者Some1Else