{
 The following class TServiceManager can be used to manage your NT-Services.
 You can do things like start, stop, pause or querying a services status.
}

// Thanks for this one to Frederik Schaller as well - it's a co-work }
unit ServiceManager;
interface
uses
 SysUtils, Windows, WinSvc;
type
 TServiceManager = class
 private
  { Private declarations }
  ServiceControlManager: SC_Handle;
  ServiceHandle: SC_Handle;
 protected
  function DoStartService(NumberOfArgument: DWORD; ServiceArgVectors: PChar): Boolean;
 public
  { Public declarations }
  function Connect(MachineName: PChar = nil; DatabaseName: PChar = nil;
  Access: DWORD = SC_MANAGER_ALL_ACCESS): Boolean; // Access may be SC_MANAGER_ALL_ACCESS
  function OpenServiceConnection(ServiceName: PChar): Boolean;
  function StartService: Boolean; overload; // Simple start
  function StartService(NumberOfArgument: DWORD; ServiceArgVectors: PChar): Boolean;
  overload; // More complex start
  function StopService: Boolean;
  procedure PauseService;
  procedure ContinueService;
  procedure ShutdownService;
  procedure DisableService;
  function GetStatus: DWORD;
  function ServiceRunning: Boolean;
  function ServiceStopped: Boolean;
 end;
implementation
{ TServiceManager }
function TServiceManager.Connect(MachineName, DatabaseName: PChar;
 Access: DWORD): Boolean;
begin
 Result := False;
 { open a connection to the windows service manager }
 ServiceControlManager := OpenSCManager(MachineName, DatabaseName, Access);
 Result := (ServiceControlManager <> 0);
end;

function TServiceManager.OpenServiceConnection(ServiceName: PChar): Boolean;
begin
 Result := False;
 { open a connetcion to a specific service }
 ServiceHandle := OpenService(ServiceControlManager, ServiceName, SERVICE_ALL_ACCESS);
 Result := (ServiceHandle <> 0);
end;
procedure TServiceManager.PauseService;
var
 ServiceStatus: TServiceStatus;
begin
 { Pause the service: attention not supported by all services }
 ControlService(ServiceHandle, SERVICE_CONTROL_PAUSE, ServiceStatus);
end;
function TServiceManager.StopService: Boolean;
var
 ServiceStatus: TServiceStatus;
begin
 { Stop the service }
 Result := ControlService(ServiceHandle, SERVICE_CONTROL_STOP, ServiceStatus);
end;
procedure TServiceManager.ContinueService;
var
 ServiceStatus: TServiceStatus;
begin
 { Continue the service after a pause: attention not supported by all services }
 ControlService(ServiceHandle, SERVICE_CONTROL_CONTINUE, ServiceStatus);
end;
procedure TServiceManager.ShutdownService;
var
 ServiceStatus: TServiceStatus;
begin
 { Shut service down: attention not supported by all services }
 ControlService(ServiceHandle, SERVICE_CONTROL_SHUTDOWN, ServiceStatus);
end;
function TServiceManager.StartService: Boolean;
begin
 Result := DoStartService(0, '');
end;
function TServiceManager.StartService(NumberOfArgument: DWORD;
 ServiceArgVectors: PChar): Boolean;
begin
 Result := DoStartService(NumberOfArgument, ServiceArgVectors);
end;
function TServiceManager.GetStatus: DWORD;
var
 ServiceStatus: TServiceStatus;
begin
{ Returns the status of the service. Maybe you want to check this
 more than once, so just call this function again.
 Results may be: SERVICE_STOPPED
  SERVICE_START_PENDING
  SERVICE_STOP_PENDING
  SERVICE_RUNNING
  SERVICE_CONTINUE_PENDING
  SERVICE_PAUSE_PENDING
  SERVICE_PAUSED }
 Result := 0;
 QueryServiceStatus(ServiceHandle, ServiceStatus);
 Result := ServiceStatus.dwCurrentState;
end;
procedure TServiceManager.DisableService;
begin
 { Implementation is following... }
end;
function TServiceManager.ServiceRunning: Boolean;
begin
 Result := (GetStatus = SERVICE_RUNNING);
end;
function TServiceManager.ServiceStopped: Boolean;
begin
 Result := (GetStatus = SERVICE_STOPPED);
end;
function TServiceManager.DoStartService(NumberOfArgument: DWORD;
 ServiceArgVectors: PChar): Boolean;
var
 err: integer;
begin
 Result := WinSvc.StartService(ServiceHandle, NumberOfArgument, ServiceArgVectors);
end;
end.