How to Use an OCX in a Console Application: A Step-by-Step Guide

Using ActiveX controls in console applications can seem daunting, especially if you’re new to programming or the C++ language. If you’ve found yourself wondering how to drop an OCX file into your console application for some quick testing, you’re not alone! This blog post will walk you through the process of doing just that, making it easy and efficient.

Understanding OCX and Its Uses

OCX files are binary files containing reusable OLE (Object Linking and Embedding) controls. Often used for embedding functionality such as user interfaces, they can be very useful in various applications, including console apps.

Getting Started with Visual C++

Assuming you already have Visual C++ installed, here’s a straightforward way to test OCX controls in your console application.

Step 1: Set Up Your Environment

Make sure you have the following in place:

• Visual C++ installed (we’ll be using cl.exe for compiling).
• Your OCX file (make sure it is registered on your system).

Step 2: Create Your Console Application

1. Create a new text file: Name it test.cpp. You will be writing your code here.
2. Open it in a text editor and copy the following code:

#include "windows.h"
#include "shobjidl.h"
#include "atlbase.h"

//
// compile with:  cl /EHsc test.cpp
//

BOOL CALLBACK RemoveFromTaskbarProc( HWND hwnd, LPARAM lParam )
{
    ITaskbarList* ptbl = (ITaskbarList*)lParam;
    ptbl->DeleteTab(hwnd);  
    return TRUE;
}

void HideTaskWindows(ITaskbarList* ptbl)
{
    EnumWindows(RemoveFromTaskbarProc, (LPARAM) ptbl);
}

BOOL CALLBACK AddToTaskbarProc( HWND hwnd, LPARAM lParam )
{
    ITaskbarList* ptbl = (ITaskbarList*)lParam;
    ptbl->AddTab(hwnd); 
    return TRUE; // continue enumerating
}

void ShowTaskWindows(ITaskbarList* ptbl)
{
    if (!EnumWindows(AddToTaskbarProc, (LPARAM) ptbl))
        throw "Unable to enum windows in ShowTaskWindows";
}

int main(int, char**)
{
    CoInitialize(0);

    try {
        CComPtr<IUnknown> pUnk;

        if (FAILED(CoCreateInstance(CLSID_TaskbarList, NULL, CLSCTX_INPROC_SERVER | CLSCTX_LOCAL_SERVER, IID_IUnknown, (void**) &pUnk)))
            throw "Unable to create CLSID_TaskbarList";

        CComQIPtr<ITaskbarList> ptbl = pUnk;
        if (ptbl)
            ptbl->HrInit();

        HideTaskWindows(ptbl);
        MessageBox(GetDesktopWindow(), _T("Check out the task bar!"), _T("StackOverflow FTW"), MB_OK);
        ShowTaskWindows(ptbl);
    }
    catch(TCHAR * msg) {
        MessageBox(GetDesktopWindow(), msg, _T("Error"), MB_OK);
    }       

    CoUninitialize();
    return 0;
}

Step 3: Compile Your Code

To compile this code, open your developer command prompt and navigate to the directory where your test.cpp file is located. Use the following command:

cl.exe /EHsc test.cpp

Step 4: Run Your Application

Once compiled, run the resulting executable. If everything is set up correctly, you should see a message box and some interaction with the Windows Taskbar.

Understanding the Code

• COM Initialization (CoInitialize): Before you call any COM functions, you need to initialize COM with CoInitialize().
• Creating an Instance: In this code, CoCreateInstance() is used to create an instance of the TaskbarList class. This is your OCX.
• Working with the Taskbar: The HideTaskWindows and ShowTaskWindows functions demonstrate how to manipulate windows in the Taskbar.

Error Handling

The use of try-catch statements ensures that any errors encountered during the execution of the program will prompt a message box with relevant information. This is crucial for debugging.

Wrapping Up

Testing an OCX in a console application doesn’t need to be an uphill battle. With the right setup and understanding of COM components and ActiveX, you can easily integrate them into your applications. Follow this step-by-step guide, and you’ll be confident using OCX controls in no time!

If you run into any issues, don’t hesitate to reach out or consult the documentation. Happy coding!