delphi - 确定是否作为 VCL 表单或服务运行

Question

我有在服务和 VCL Form 应用程序(win32 应用程序)中使用的代码。如何确定底层应用程序是作为 NT 服务还是作为应用程序运行？

谢谢。

Answer 1

开始编辑

由于这似乎仍然受到一些关注，我决定用缺少的信息和更新的 Windows 补丁来更新答案。在任何情况下，您都不应该复制/粘贴代码。该代码只是展示应该如何完成事情。

编辑结束:

您可以检查父进程是否是SCM(服务控制管理器)。如果您作为服务运行，则始终是这种情况，而如果作为标准应用程序运行，则绝不会出现这种情况。另外我认为SCM总是有相同的PID。

你可以这样检查:

type
  TAppType = (atUnknown, atDesktop, atService);

var
  AppType: TAppType;

function InternalIsService: Boolean;
var
  PL: TProcessList;
  MyProcessId: DWORD;
  MyProcess: PPROCESSENTRY32;
  ParentProcess: PPROCESSENTRY32;
  GrandParentProcess: PPROCESSENTRY32;
begin
  Result := False;

  PL := TProcessList.Create;
  try
    PL.CreateSnapshot;
    MyProcessId := GetCurrentProcessId;

    MyProcess := PL.FindProcess(MyProcessId);
    if MyProcess <> nil then
    begin
      ParentProcess := PL.FindProcess(MyProcess^.th32ParentProcessID);
      if ParentProcess <> nil then
      begin
        GrandParentProcess := PL.FindProcess(ParentProcess^.th32ParentProcessID);

        if GrandParentProcess <> nil then
        begin
          Result := SameText(string(ParentProcess^.szExeFile), 'services.exe') and
            (SameText(string(GrandParentProcess^.szExeFile), 'winlogon.exe') or
             SameText(string(GrandParentProcess^.szExeFile), 'wininit.exe'));
        end;
      end;
    end;
  finally
    PL.Free;
  end; 
end;

function IsService: Boolean;
begin
  if AppType = atUnknown then
  begin
    try
      if InternalIsService then
        AppType := atService
      else
        AppType := atDesktop;
    except
      AppType := atService;
    end;
  end;

  Result := AppType = atService;
end;

initialization
  AppType := atUnknown;

TProcessList 是这样实现的(同样不包括 THashTable，但任何哈希表都应该没问题):

type
  TProcessEntryList = class(TList)
  private
    function Get(Index: Integer): PPROCESSENTRY32;
    procedure Put(Index: Integer; const Value: PPROCESSENTRY32);
  public
    property Items[Index: Integer]: PPROCESSENTRY32 read Get write Put; default;
    function Add(const Entry: TProcessEntry32): Integer; reintroduce;
    procedure Clear; override;
  end;

  TProcessList = class
  private
    ProcessIdHashTable: THashTable;
    ProcessEntryList: TProcessEntryList;
  public
    constructor Create; reintroduce;
    destructor Destroy; override;
    procedure CreateSnapshot;
    function FindProcess(const ProcessId: DWORD): PPROCESSENTRY32;
  end;

implementation

{ TProcessEntryList }

procedure TProcessEntryList.Clear;
var
  i: Integer;
begin
  i := 0;
  while i < Count do
  begin
    FreeMem(Items[i]);
    Inc(i);
  end;

  inherited;
end;

procedure TProcessEntryList.Put(Index: Integer; const Value: PPROCESSENTRY32);
var
  Item: Pointer;
begin
  Item := inherited Get(Index);
  CopyMemory(Item, Value, SizeOf(tagPROCESSENTRY32));
end;

function TProcessEntryList.Get(Index: Integer): PPROCESSENTRY32;
begin
  Result := PPROCESSENTRY32(inherited Get(Index));
end;

function TProcessEntryList.Add(const Entry: TProcessEntry32): Integer;
var
  EntryCopy: PPROCESSENTRY32;
begin
  GetMem(EntryCopy, SizeOf(tagPROCESSENTRY32));
  CopyMemory(EntryCopy, @Entry, SizeOf(tagPROCESSENTRY32));

  Result := inherited Add(EntryCopy);  
end;

{ TProcessList }

constructor TProcessList.Create;
begin
  inherited;

  ProcessEntryList := TProcessEntryList.Create;
  ProcessIdHashTable := THashTable.Create;
end;

destructor TProcessList.Destroy;
begin
  FreeAndNil(ProcessIdHashTable);
  FreeAndNil(ProcessEntryList);

  inherited;
end;

function TProcessList.FindProcess(const ProcessId: DWORD): PPROCESSENTRY32;
var
  ItemIndex: Integer;
begin
  Result := nil;
  if not ProcessIdHashTable.ContainsKey(IntToStr(ProcessId)) then
    Exit;

  ItemIndex := Integer(ProcessIdHashTable.Item[IntToStr(ProcessId)]);
  Result := ProcessEntryList.Items[ItemIndex];
end;

procedure TProcessList.CreateSnapshot;
var
  SnapShot: THandle;
  ProcessEntry: TProcessEntry32;
  ItemIndex: Integer;
begin
  SnapShot := CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
  if SnapShot <> 0 then
  try
    ProcessEntry.dwSize := SizeOf(ProcessEntry);
    if Process32First(SnapShot, ProcessEntry) then
    repeat
      ItemIndex := ProcessEntryList.Add(ProcessEntry);
      ProcessIdHashTable.Add(IntToStr(ProcessEntry.th32ProcessID), TObject(ItemIndex));
    until not Process32Next(SnapShot, ProcessEntry);
  finally
    CloseHandle(SnapShot);
  end;
end;