delphi - 如何在 Delphi for Windows 8 中启动 Windows 服务

Question

我需要使用 Delphi Windows 应用程序启动一个服务。它在 Windows 7 中工作正常，但在 Windows 8.1 中无法工作。我使用了以下代码

function ServiceStart(sMachine,sService : string ) : boolean;
var
  schm,schs   : SC_Handle;
  ss     : TServiceStatus;
  psTemp : PChar;
  dwChkP : DWord;
begin
  ss.dwCurrentState := 0;
  schm := OpenSCManager(PChar(sMachine),Nil,SC_MANAGER_CONNECT);
  if(schm > 0)then
  begin
    schs := OpenService(schm,PChar(sService),SERVICE_START or SERVICE_QUERY_STATUS);
    if(schs > 0)then
    begin
      psTemp := Nil;
      if(StartService(schs,0,psTemp))then
      begin
        if(QueryServiceStatus(schs,ss))then
        begin
          while(SERVICE_RUNNING <> ss.dwCurrentState)do
          begin
            dwChkP := ss.dwCheckPoint;
            Sleep(ss.dwWaitHint);
            if(not QueryServiceStatus(schs,ss))then
            begin
              break;
            end;
            if(ss.dwCheckPoint < dwChkP)then
            begin
              break;
            end;
          end;
        end;
      end;
      CloseServiceHandle(schs);
    end;
    CloseServiceHandle(schm);
  end;


  Result := SERVICE_RUNNING = ss.dwCurrentState;
end;


procedure TForm1.BBSerStatusClick(Sender: TObject);
begin
  ServiceStart('','SERVTEST');
end;

注意:SERVTEST是服务应用程序。谁能帮我？

Answer 1

我发现您正在使用从 here 复制的代码.

if(schm > 0)then和if(schs > 0)then应更改为if(schm <> 0)then和if(schs <> 0) then反而。这种情况下唯一的失败值为 0(某些 API 使用 INVALID_HANDLE_VALUE 代替，但 SCM API 不使用)。 任何其他值都是有效句柄。句柄并不是真正的整数(尽管 Delphi 如此声明它们)，因此不应将它们视为整数。它们是任意值，不应被解释，而是应按原样使用。如果您没有返回实际的失败值(在本例中为 0)，则无论实际返回的值如何，调用都是成功的。

ss.dwCurrentState的处理也有点偏了。而不是循环 while ss.dwCurrentState不是SERVICE_RUNNING , 循环 while ss.dwCurrentState是 SERVICE_START_PENDING反而。如果出现问题并且服务永远不会进入 SERVICE_RUNNING状态，循环将永远运行，除非 QueryServiceStatus()本身失败了。我不建议依赖 ss.dwCheckPoint因为并非所有服务都正确实现它(事实上，Delphi 自己的 TService 没有 - 请参阅 QC #1006 TService.ReportStatus reports incorrect CheckPoint )。

尝试类似以下的操作。它区分 SCM API 失败和服务启动失败，而且还执行额外的错误检查来处理某些实际上不是 fatal error 的错误:

function ServiceStart(sMachine, sService : string) : Boolean;
var
  schm, schs : SC_HANDLE;
  ss : TServiceStatus;
begin
  schm := OpenSCManager(PChar(sMachine), nil, SC_MANAGER_CONNECT);
  if (schm = 0) then RaiseLastOSError;
  try
    schs := OpenService(schm, PChar(sService), SERVICE_START or SERVICE_QUERY_STATUS);
    if (schs = 0) then RaiseLastOSError;
    try
      // NOTE: if you use a version of Delphi that incorrectly declares
      // StartService() with a 'var' lpServiceArgVectors parameter, you
      // can't pass a nil value directly in the 3rd parameter, you would
      // have to pass it indirectly as either PPChar(nil)^ or PChar(nil^)
      if not StartService(schs, 0, nil) then
      begin
        Result := ERROR_SERVICE_ALREADY_RUNNING = GetLastError();
        if not Result then RaiseLastOSError;
        Exit;
      end;
      repeat
        if not QueryServiceStatus(schs, ss) then
        begin
          if (ERROR_SERVICE_NOT_ACTIVE <> GetLastError()) then RaiseLastOSError;
          Result := False;
          Exit;
        end;
        if (SERVICE_START_PENDING <> ss.dwCurrentState) then Break;
        Sleep(ss.dwWaitHint);
      until False;
      Result := SERVICE_RUNNING = ss.dwCurrentState;
    finally
      CloseServiceHandle(schs);
    end;
  finally
    CloseServiceHandle(schm);
  end;
end;

或者，这里是 Microsoft 示例的(修改后的)版本，其中还包括服务位于 SERVICE_STOP_PENDING 中的处理。启动之前的状态(我删除了超时逻辑，因为它基于 dwCheckPoint 处理):

Starting a Service :

function ServiceStart(sMachine, sService : string) : Boolean;
var
  schSCManager,
  schService : SC_HANDLE;
  ssStatus : TServiceStatus;
begin
  // Get a handle to the SCM database.

  schSCManager := OpenSCManager(PChar(sMachine), nil, SC_MANAGER_CONNECT);
  if (schSCManager = 0) then RaiseLastOSError; 
  try
    // Get a handle to the service.

    schService := OpenService(schSCManager, PChar(sService), SERVICE_START or SERVICE_QUERY_STATUS);
    if (schService = 0) then RaiseLastOSError;
    try
      // Check the status in case the service is not stopped.

      if not QueryServiceStatus(schService, ssStatus) then
      begin
        if (ERROR_SERVICE_NOT_ACTIVE <> GetLastError()) then RaiseLastOSError;
        ssStatus.dwCurrentState := SERVICE_STOPPED;
      end;

      // Check if the service is already running

      if (ssStatus.dwCurrentState <> SERVICE_STOPPED) and ssStatus.dwCurrentState <> SERVICE_STOP_PENDING) then
      begin
        Result := True;
        Exit;
      end;

      // Wait for the service to stop before attempting to start it.

      while (ssStatus.dwCurrentState = SERVICE_STOP_PENDING) do
      begin
        // Do not wait longer than the wait hint. A good interval is
        // one-tenth of the wait hint but not less than 1 second
        // and not more than 10 seconds.

        dwWaitTime := ssStatus.dwWaitHint div 10;

        if (dwWaitTime < 1000) then
          dwWaitTime := 1000
        else if (dwWaitTime > 10000) then
          dwWaitTime := 10000;

        Sleep(dwWaitTime);

        // Check the status until the service is no longer stop pending.

        if not QueryServiceStatus(schService, ssStatus) then
        begin
          if (ERROR_SERVICE_NOT_ACTIVE <> GetLastError()) then RaiseLastOSError;
          Break;
        end;
      end;

      // Attempt to start the service.

      // NOTE: if you use a version of Delphi that incorrectly declares
      // StartService() with a 'var' lpServiceArgVectors parameter, you
      // can't pass a nil value directly in the 3rd parameter, you would
      // have to pass it indirectly as either PPChar(nil)^ or PChar(nil^)
      if not StartService(schService, 0, nil) then RaiseLastOSError;

      // Check the status until the service is no longer start pending.

      if not QueryServiceStatus(schService, ssStatus) then
      begin
        if (ERROR_SERVICE_NOT_ACTIVE <> GetLastError()) then RaiseLastOSError;
        ssStatus.dwCurrentState := SERVICE_STOPPED;
      end;

      while (ssStatus.dwCurrentState = SERVICE_START_PENDING) do
      begin
        // Do not wait longer than the wait hint. A good interval is
        // one-tenth the wait hint, but no less than 1 second and no
        // more than 10 seconds.

        dwWaitTime := ssStatus.dwWaitHint div 10;

        if (dwWaitTime < 1000) then
          dwWaitTime := 1000
        else if (dwWaitTime > 10000) then
          dwWaitTime := 10000;

        Sleep(dwWaitTime);

        // Check the status again.

        if not QueryServiceStatus(schService, ssStatus) then
        begin
          if (ERROR_SERVICE_NOT_ACTIVE <> GetLastError()) then RaiseLastOSError;
          ssStatus.dwCurrentState := SERVICE_STOPPED;
          Break;
        end;
      end;

      // Determine whether the service is running.

      Result := (ssStatus.dwCurrentState = SERVICE_RUNNING);
    finally
      CloseServiceHandle(schService); 
    end;
  finally
    CloseServiceHandle(schSCManager);
  end;
end;