Creating the Project (ATL Tutorial, Part 1)

This tutorial walks you step-by-step through a non-attributed ATL project that creates an ActiveX object that displays a polygon. The object includes options for allowing the user to change the number of sides making up the polygon, and code to refresh the display.

Note

This tutorial creates the same source code as the Polygon sample. If you want to avoid entering the source code manually, you can download it from the Polygon sample abstract. You can then refer to the Polygon source code as you work through the tutorial, or use it to check for errors in your own project. To compile, open pch.h (stdafx.h in Visual Studio 2017 and earlier) and replace:

#ifndef WINVER
#define WINVER 0x0400
#endif

with

#ifndef WINVER
#define WINVER 0x0500
#define _WIN32_WINNT 0x0500
#endif

The compiler will still complain about regsvr32 not exiting correctly, but you should still have the control's DLL built and available for use.

To create the initial ATL project using the ATL Project Wizard

1. In Visual Studio 2017 and earlier: File > New > Project. The open the Visual C++ tab and select MFC/ATL. Select ATL Project.

   In Visual Studio 2019: Choose File > New > Project, type "atl" in the search box, and choose ATL Project.

2. Type Polygon as the project name.

   The location for the source code will usually default to \Users\<username>\source\repos, and a new folder will be created automatically.

3. In Visual Studio 2019, accept the default values and click OK. In Visual Studio 2017, click OK to open the ATL Project wizard. Click Application Settings to see the options available. Because this project creates a control, and a control must be an in-process server, leave the Application type as a DLL. Click OK.

Visual Studio will create the project by generating several files. You can view these files in Solution Explorer by expanding the Polygon object. The files are listed below.

File	Description
Polygon.cpp	Contains the implementation of DllMain, DllCanUnloadNow, DllGetClassObject, DllRegisterServer, and DllUnregisterServer. Also contains the object map, which is a list of the ATL objects in your project. This is initially blank.
Polygon.def	This module-definition file provides the linker with information about the exports required by your DLL.
Polygon.idl	The interface definition language file, which describes the interfaces specific to your objects.
Polygon.rgs	This registry script contains information for registering your program's DLL.
Polygon.rc	The resource file, which initially contains the version information and a string containing the project name.
Resource.h	The header file for the resource file.
Polygonps.def	This module definition file provides the linker with information about the exports required by the proxy and stub code that support calls across apartments.
pch.cpp	The file that will #include pch.h.
pch.h	The file that will #include and precompile the ATL header files.

1. In Solution Explorer, right-click the Polygon project.

2. On the shortcut menu, click Properties.

3. Click on Linker. Change the Per-UserRedirection option to Yes.

4. Click OK.

In the next step, you will add a control to your project.

On to Step 2

See also

Tutorial