Top VB6 OCX Pack Components Every Developer Should Know

Top VB6 OCX Pack Components Every Developer Should KnowVisual Basic 6 (VB6) remains in use across many enterprises and legacy systems. Developers maintaining or modernizing these applications frequently rely on OCX (OLE Control Extension) components—ActiveX controls packaged as .ocx files—to add UI elements, data handling, printing, and system integration features that either weren’t in the VB6 runtime or provided more polished behavior. This article surveys the most useful OCX components a VB6 developer should know, explains what each component does, where it’s commonly used, and offers practical tips for installation, registration, versioning, and troubleshooting.

Why OCX components still matter

While moving to .NET or modern frameworks is ideal for many projects, full rewrites are costly and risky. OCX controls provide a way to:

Add advanced UI widgets (grids, charts, tree controls) quickly.
Reuse well-tested functionality (reporting, printing, ActiveX integration).
Bridge VB6 to other system services (COM servers, device APIs).
Speed up maintenance and incremental modernization.

Common categories of OCX components

UI controls (grids, treeviews, tab controls, rich text)
Data and database helpers (enhanced ADO controls, data grids)
Reporting and printing controls
Multimedia and graphics (charts, image viewers)
System and utility controls (serial/COM, FTP, zip)
Third-party frameworks and toolkits that bundle many OCX controls

Top OCX components every VB6 developer should know

1) Grid and Data Display Controls

Grids are core to many business apps—displaying tabular data, supporting sorting, editing, filtering, and custom drawing.

Typical examples: MSFlexGrid/MSHFlexGrid (Microsoft), third-party grids like True DBGrid or ComponentOne grids.
What they provide: cell-level formatting, pagination, built-in column types, in-place editors, copy/paste, and sometimes virtual-mode for large datasets.
Use cases: data entry forms, admin consoles, report viewers.
Tips: prefer virtual or owner-draw modes for very large datasets to avoid memory/UX issues.

2) TreeView and List Controls

Hierarchical and multi-column list displays are common in file managers, configuration GUIs, and navigation panes.

Examples: Microsoft TreeView/ListView (from comctl32.ocx), enhanced third-party list controls.
What they provide: drag-and-drop between nodes, checkboxes, icons, multi-column details, lazy loading.
Use cases: project explorers, hierarchical data editors.
Tips: keep node counts reasonable and implement lazy loading for deep hierarchies.

3) RichText and HTML View Controls

Text formatting, copy/paste with styles, and HTML rendering inside forms.

Examples: RichTextBox control, Internet Explorer WebBrowser control (used as an embedded HTML viewer).
What they provide: styled text editing, OLE embedding, printing support, scripting in HTML viewers.
Use cases: document editors, help viewers, formatted logs.
Tips: WebBrowser embeds a full IE engine—be mindful of security zones and registry-related behaviors.

4) Charting and Visualization Controls

Charts, gauges, and graphs make data easier to interpret.

Examples: MSChart (Microsoft), third-party chart OCXs like TeeChart or Dundas Chart.
What they provide: line/bar/pie charts, multiple series, custom axes, tooltips, export capabilities.
Use cases: dashboards, analytics panels, real-time monitoring.
Tips: choose a control that supports image export (PNG/JPEG) if you need to create reports.

5) Reporting & Print Controls

Professional reporting and print-preview functionality is often achieved with OCX-based report designers/viewers.

Examples: Crystal Reports runtime OCX (older versions), ActiveReports, Data Dynamics ReportViewer, and third-party print preview controls.
What they provide: designers, parameterized reports, export to PDF/RTF, pagination, print dialogs.
Use cases: invoices, batch reports, complex document generation.
Tips: ensure runtime redistribution rights and include proper OCX registration steps in installers.

6) File Compression & Archive Controls

Zip/unzip, spawning archives, password protection—useful where file exchange or data packaging is required.

Examples: Zip OCXs (ComponentOne, Info-ZIP wrappers, or WinZip/PKZip ActiveX runtimes).
What they provide: compress/extract files, create self-extracting archives, progress callbacks.
Use cases: backup utilities, deployment helpers, file-transfer prep.
Tips: validate compression library licensing; ensure Unicode/file-path support for modern systems.

7) Networking, FTP, and Internet Controls

Simplified APIs for HTTP, FTP, SMTP, and sockets via ActiveX.

Examples: Microsoft Internet Transfer Control (Inet), Winsock control, third-party FTP/HTTP ActiveX components.
What they provide: higher-level HTTP/FTP operations, asynchronous events, MIME handling.
Use cases: automated uploads, remote configuration, email sending.
Tips: use secure protocols (FTPS/HTTPS) where supported; many legacy controls lack TLS 1.2+—test on current OSes.

8) Serial Port / Hardware Interface Controls

Direct access to serial (COM) ports, barcode scanners, scales, and other peripherals.

Examples: MSComm (Microsoft), third-party serial OCXs with enhanced buffer control and event handling.
What they provide: read/write serial data, event-driven receive, baud/settings management.
Use cases: point-of-sale, industrial equipment interfaces, device configuration tools.
Tips: modern Windows versions may virtualize devices—ensure correct COM port mapping and user permissions.

9) ActiveX Scripting and Automation Controls

Embedding scripting engines or hosting automation for macros and extensibility.

Examples: Microsoft ScriptControl (MSScript.ocx), custom script hosts.
What they provide: host VBScript/JScript, evaluate expressions, bind to objects for macro engines.
Use cases: user-customizable automation, dynamic business rules.
Tips: be careful about executing untrusted scripts—implement sandboxing or restrict accessible objects.

10) Utility Controls (Zip, Registry, Date/Time Pickers)

Small but widely used helpers to manipulate system resources.

Examples: DateTimePicker (comctl), registry access OCXs, drag-and-drop helpers.
What they provide: standard UI widgets and system access helpers.
Use cases: configuration dialogs, installer utilities.
Tips: prefer native Windows controls where possible to minimize redistribution.

Installation, registration, and distribution best practices

Registering OCXs: use regsvr32.exe (e.g., regsvr32 mycontrol.ocx). For 32-bit VB6 apps on 64-bit Windows, register OCXs using the 32-bit regsvr32 located in SysWOW64.
Redistributables: check license terms for each OCX. Vendor redistributable packages often include installers and merge modules; prefer those to manual registration when building installers.
Versioning: avoid “DLL Hell” by documenting required OCX filenames and version GUIDs. Use side-by-side files in dedicated application folders when possible.
Installer tips: create an installer (Inno Setup, NSIS, or commercial installers) that registers OCXs during install and unregisters on uninstall. Include prerequisites like VB6 runtimes and MS common controls.
Digital signing: sign installers and OCX binaries when possible to reduce Windows SmartScreen and trust prompts.

Troubleshooting common OCX issues

Unregistered control errors: “Component not registered” — fix with regsvr32 and ensure correct bitness.
Missing dependencies: use Dependency Walker / modern alternatives to find missing DLLs.
Version mismatch: controls developed for older comctl versions may behave differently; check for required service packs.
Permissions: COM registration requires administrator rights; runtime access sometimes needs elevated privileges.
64-bit host incompatibility: 32-bit OCXs cannot be loaded by 64-bit processes. Run VB6 apps as 32-bit or use a surrogate process.
Security and TLS: older networking OCXs may not support modern TLS. Replace or wrap with updated components.

When to replace OCX controls vs. keep them

Keep them if: application stability is paramount, the OCX is well-tested, licensing allows redistribution, and functionality isn’t security-critical.
Replace or modernize if: the OCX lacks security updates, doesn’t run on current Windows versions, or blocks necessary features (modern TLS, Unicode support).
Incremental modernization: wrap OCX functionality behind a COM wrapper or write a small .NET interop layer to modernize gradually.

Recommended migration paths

Short term: isolate OCX usage to modules; write wrapper classes to abstract control-specific APIs.
Mid term: replace UI controls with .NET UserControls hosted via COM interop (or migrate forms gradually).
Long term: reimplement core modules in a modern stack (C#, .NET ⁄₇+, web UI) while using interoperability for stable legacy features.

Example: packaging an OCX with an installer (high-level steps)

Identify OCX file(s) and any dependent DLLs.
Include regsvr32 registration commands in your installer script for 32-bit or 64-bit environments accordingly.
Add logic to install VB6 runtime and Microsoft Common Controls prerequisites.
Test installation on clean VMs (both x86 and x64 Windows versions you support).
Provide an uninstall path that unregisters OCXs.

Security considerations

Avoid running untrusted OCXs. Treat ActiveX controls as native code with full system access.
Prefer signed binaries and validate vendor reputation.
Monitor for controls that use deprecated crypto or network protocols.

Quick reference table of popular OCX types and use cases

OCX Type	Typical Examples	Key Use Cases
Grid Controls	MSFlexGrid, True DBGrid	Data entry, tabular displays
Tree/List Controls	TreeView/ListView (comctl)	Hierarchical navigation
Charting	MSChart, TeeChart	Dashboards, reports
Reporting	Crystal Reports OCX, ActiveReports	Invoices, reports
Networking	Inet, Winsock	FTP/HTTP/email
Serial/Hardware	MSComm	POS, device integration
Rich Text/HTML	RichTextBox, WebBrowser	Editors, help viewers
Compression	Zip OCXs	Archiving, backups

Final notes

OCX components remain a practical tool for VB6 maintenance and incremental modernization. Knowing which controls solve which problems, how to deploy them correctly, and when to replace them will help keep legacy apps secure, maintainable, and functional while you plan longer-term migration.

If you want, I can: provide a checklist for packaging an OCX in an installer, create a small wrapper example in VB6 for a specific OCX (specify which), or list current third-party vendors and redistributable links.