INFO: Active Template Library (ATL) 2.0 Readme File

• Microsoft Active Template Library, version 2.0 on the following platform: x86

SUMMARY

The following information is taken from the February 14, 1997 Readme file of the Active Template Library (ATL) version 2.0.

MORE INFORMATION

Active Template Library 2.0 Readme

ATL 2.0 requires Oleaut32.dll version 2.20.4049, or later, which is shipped with Windows NT 4.0 and Internet Explorer 3.0. ATL 2.0 also requires the Visual C++ 4.2b patch.

Building ATL Projects from the Command Line Can Generate NMAKE Error

Building an ATL project from the command line can generate NMAKE error U1073. (This problem does not occur when building ATL samples from within the integrated development environment.)

For example, the following command line:

   nmake /f beeper.mak CFG="beeper - Win32 Release"

   NMAKE : fatal error U1073: don't know how to make '".\beeper.h"'

To work around this problem, use the following commands:

   nmake /f beeper.mak CFG="beeper - Win32 Release" beeper.h
   nmake /f beeper.mak CFG="beeper - Win32 Release"

_ATL_MIN_CRT and Link Error "unresolved external symbol _main"

When you build a Release version of an ATL project, you can get the following link error:

   LIBCMT.LIB(crt0.obj) : error LNK2001: unresolved external symbol _main

• Remove _ATL_MIN_CRT from the list of preprocessor defines to allow CRT startup code to be included. On the Build menu, click Settings. Hold the ctrl key while selecting all Release configurations. On the C/C++ tab, choose the General category, then remove _ATL_MIN_CRT from the preprocessor definitions edit box.
• If possible, remove calls to CRT functions that require CRT startup code. Instead, use their Win32 equivalents. For example, use lstrcmp() instead of strcmp(). Known functions that require CRT startup code are some of the string and floating point functions.

Service EXE Created with ATL COM AppWizard Doesn't Build in Release Mode

In the ATL COM AppWizard, if you choose Service (EXE) as the server type, your project will not build in release mode. Builds in release mode automatically include the preprocessor directive _ATL_MIN_CRT, while the default ATL service code requires the CRT library. To avoid this error, do one of the following:

• Remove _ATL_MIN_CRT from the list of preprocessor defines to allow CRT startup code to be included. On the Build menu, click Settings. Hold the ctrl key while selecting all Release configurations. On the C/C++ tab, choose the General category, then remove _ATL_MIN_CRT from the Preprocessor definitions edit box.
• Remove calls to CRT functions within the generated ServiceModule::LogEvent function.

ATL Controls in Visual Basic 5.0 Containers

If you are using the IQuickActivate interface in Visual Basic 5.0, you must also support the connection point IPropertyNotifySink. To use a control generated by the ATL Object Wizard in a Visual Basic 5.0 container, you must either add support for IPropertyNotifySink or remove the dependence on the IQuickActivate interface. To remove IQuickActivate support, comment out the lines containing IQuickActivateImpl in the control's class inheritance list and in the COM interface map. For example, if you generate a full control called MyCtl with the ATL Object Wizard, then go to MyCtl.h and comment out the line containing IQuickActivateImpl in the CMyCtl class inheritance list:

   class ATL_NO_VTABLE CMyCtl :
   ...

   // public IQuickActivateImpl<CMyCtl>

   BEGIN_COM_MAP(CMyCtl)
   ...

   // COM_INTERFACE_ENTRY_IMPL(IQuickActivate)

Some ATL Object Stock Properties Must Be Initialized

Before Use in Visual Basic 5.0 Containers, Visual Basic 5.0 expects all stock properties that are IUnknown-based (such as MousePointer, Picture, and Font) to contain a valid IUnknown pointer. Otherwise, Visual Basic never allows the user to change the property. For example, if you have a stock Font property that you never fill in with a valid Font, Visual Basic will display the Font as being NULL, and will never allow the user to select a new Font through the Visual Basic property window.

To avoid this problem, make sure your IUnknown-based stock properties have a valid value other than NULL before inserting your object into a Visual Basic container. There are many ways to do this, for example, get the ambient Font off the container and use that as your stock Font property.

ATL Registrar Fails to Insert Keys Starting with Curly Brace

The ATL registrar does not correctly interpret two consecutive key names that both start with a curly brace '{'. For example, the second "Implemented Categories" key name fails in the following registry script (rgs):

   HKCR

   {
      NoRemove CLSID
      {
        ForceRemove {333C7BC4-460F-11D0-BC04-0080C7055A83} = s 'Tabular
        Data Control'
        {
           'Implemented Categories'
           {
             '{7DD95801-9882-11CF-9FA9-00AA006C42C4}'
             '{7DD95802-9882-11CF-9FA9-00AA006C42C4}'
           }
        }
      }
   }

   HKCR
   {
      NoRemove CLSID
      {
        ForceRemove {333C7BC4-460F-11D0-BC04-0080C7055A83} = s 'Tabular
        Data Control'

      {
        'Implemented Categories'
        {
          '{7DD95801-9882-11CF-9FA9-00AA006C42C4}'
        }
        'Implemented Categories'
        {
          '{7DD95802-9882-11CF-9FA9-00AA006C42C4}'
        }
      }
     }
   }

IPropertyPageImpl::Help is Implemented Incorrectly

In most cases, if you are using property pages, you should override IPropertyPage::Help and return E_NOTIMPL. This will cause the container to use information returned from GetPageInfo. You can also provide your own alternative implementation of this function if necessary.

ATL Font and Picture Properties May Require Changes to the IDL File

To make a Font or Picture property work in some containers, the interface definition must be declared within the library section of the .idl file. You must cut the interface declarations from the .idl file and paste them into the library section of the same file. In addition, the import line for ocidl.idl needs to be commented out. For example, the ATL Object Wizard generates the following .idl file for MyCtl with a Font property:

   import "oaidl.idl";
   import "ocidl.idl";

   [
      object,
      uuid(8697BC4C-7A38-11D0-9A38-00A0C90DC94B),
      dual,
      helpstring("IMyCtl Interface"),
      pointer_default(unique)
   ]

   interface IMyCtl : IDispatch
   {
      [propputref, id(DISPID_FONT)]
      HRESULT Font([in]IFontDisp* pFont);
      [propput, id(DISPID_FONT)]
      HRESULT Font([in]IFontDisp* pFont);
      [propget, id(DISPID_FONT)]
      HRESULT Font([out, retval]IFontDisp** ppFont);
   };

   [
      uuid(8697BC3F-7A38-11D0-9A38-00A0C90DC94B),
      version(1.0),
      helpstring("MyControl 1.0 Type Library")
   ]

   library MYCONTROLLib
   {
      importlib("stdole32.tlb");
      importlib("stdole2.tlb");
      [
      uuid(8697BC4D-7A38-11D0-9A38-00A0C90DC94B),
      helpstring("MyCtl Class")
      ]

      coclass MyCtl
      {
         [default] interface IMyCtl;
      };
   };

   import "oaidl.idl";
   // import "ocidl.idl";
   [
      uuid(8697BC3F-7A38-11D0-9A38-00A0C90DC94B),
      version(1.0),
      helpstring("MyControl 1.0 Type Library")
   ]

   library MYCONTROLLib
   {
      importlib("stdole32.tlb");
      importlib("stdole2.tlb");
      [
         object,
         uuid(8697BC4C-7A38-11D0-9A38-00A0C90DC94B),
         dual,
         helpstring("IMyCtl Interface"),
         pointer_default(unique)
      ]

      interface IMyCtl : IDispatch
      {
         [propputref, id(DISPID_FONT)]
         HRESULT Font([in]IFontDisp* pFont);
         [propput, id(DISPID_FONT)]
         HRESULT Font([in]IFontDisp* pFont);
         [propget, id(DISPID_FONT)]
         HRESULT Font([out, retval]IFontDisp** ppFont);
      };
      [
         uuid(8697BC4D-7A38-11D0-9A38-00A0C90DC94B),
         helpstring("MyCtl Class")
      ]

      coclass MyCtl
      {
         [default] interface IMyCtl;
      };
   };

Changes to Stock Property Macros

The documentation incorrectly references the macro IMPLEMENT_SMARTPTR_STOCKPROP. This macro is now obsolete. The macro IMPLEMENT_BOOL_STOCKPROP has been added and should be used for all stock properties that are Boolean values, such as the standard BORDERVISIBLE, ENABLED, TABSTOP, and VALID stock properties.

Problems with ATL Samples

The samples ATLCON and ATLBUTTON have the following problems:

• To successfully run ATLCON under a MinCRT configuration, you must remove the WinMain entry point as follows:

  1. Click Settings on the Build menu. 2. Under Settings For, choose one of the MinCRT configurations. 3. On the Link tab, choose the Output category. 4. Remove the text in the Entry-point symbol editbox.

• ATLButton returns incorrect values for the properties ImageHover and ImagePush. To correct the sample, change the file AtlButton.h so that the function get_ImageHover uses m_bstrFileName[1].Copy() and change get_ImagePush so that it uses m_bstrFileName[2].Copy().

ATL Classes in ClassView

To prevent the ATL classes from displaying in ClassView, modify (or create) the msvcincl.dat file, as follows:

1. Using a text editor, open or create msvcincl.dat. This file must be located in your Windows directory. Add a list of the ATL file names to msvcincl.dat. For example:

   atlbase.h atlcom.h atlctl.h atlwin.h ...

   (For each name you add to msvcincl.dat, ClassView will exclude the classes contained in that file.)

2. Save msvcincl.dat in your Windows directory.

3. Delete your project's .ncb file and restart Developer Studio.

Organization of Documentation

The documentation for ATL 2.0 consists of both .htm and .doc files. To navigate through the documentation in an online format, use the .htm files with your Web browser. The file start.htm provides a starting point.

If you want to print the documentation, use the .doc files. The following table shows each ATL topic and its corresponding .doc file: