Userform tools > WebView2 for Excel VBA

🚀 VBA WebView2 Integration Project

Overview

This project is a next-generation VBA development framework that aims to directly place and control Microsoft Edge WebView2 on UserForms—without requiring external library installations or setting ActiveX references from Excel VBA.

With the end of support for Internet Explorer (IE), browser control in VBA has reached a major turning point. This repository hacks the WebView2Loader.dll natively embedded in modern Office installations, bypassing standard VBA limitations to provide a modern UI/UX via low-level COM manipulation using DispCallFunc.

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🔥 Project Breakthroughs

Previously, using WebView2 from VBA required building a .NET COM wrapper and registering it in the Windows Registry (which demands Administrator privileges)—an impractical barrier for corporate environments.

However, this project achieves zero-dependency operation based on the following discoveries:

• Leveraging Pre-installed Assets: By directly tapping into the WebView2Loader.dll found inside: C:\Program Files\Microsoft Office\root\Office16\ADDINS\Microsoft Power Query for Excel Integrated\bin using standard Declare statements, we can spin up a WebView2 Environment without altering the host OS environment.
• Pure vTable Hacking: Once the WebView2Environment is captured, every single operation is executed via function pointer calls using DispCallFunc. This achieves a complete Zero-Reference-Setting architecture.

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🛠 Setup & Initialization Flow

The precise, under-the-hood process to capture the WebView2 object is as follows:

1. Create Environment: Call CreateCoreWebView2EnvironmentWithOptions from WebView2Loader.dll.
2. Await Callback: Intercept the completion notification via a standard module.
3. Generate Controller: Execute CreateCoreWebView2Controller to reserve the browser viewport.
4. Capture WebView2: Trap the core ICoreWebView2 instance using the GetWebView2 method.
5. Window Fitting: Use Windows APIs to find the Chrome_WidgetWin_0 class window and fit it pixel-perfect onto the VBA UserForm.

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🌟 The Future We Unlock

By completing this project, VBA developers will unlock:

• Modern GUI Integration: Build rich user interfaces inside UserForms using modern HTML5, CSS3, and JavaScript.
• Moving Away from Legacy ActiveX: Replace notoriously unstable TreeViews and ListViews with high-performance, web-based components.
• Full Control via Event Handlers: Complete mastery over web scraping and automated browser manipulation by self-implementing event handlers (such as NavigationCompleted).

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⚠️ Troubleshooting: Excel Crashes on Form Startup (Memory Address Table Issue)

Problem

When you open the UserForm, Excel might crash immediately with an "Automation error / Exception occurred" or a silent termination.

This happens because the VBA compiler sometimes fails to statically evaluate or initialize the memory address of standard module functions using AddressOf if they are not explicitly called or held elsewhere. If VBA doesn't map these addresses correctly, calling low-level Win32 APIs (like DispCallFunc or CreateCoreWebView2EnvironmentWithOptions) will lead to an access violation (Null/Invalid pointer crash).

Solution

To force the VBA compiler to evaluate AddressOf and keep the vTable memory address valid, add a dummy Sub at the bottom of your standard module:

' Dummy Sub to prevent VBA compiler optimization / address loss
Public Sub RegisterNavigationCompleted_()
    Static vTable As LongPtr
    vTable = GetAddr(AddressOf Handler_QueryInterface)
End Sub

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📚 謝辞

本プロジェクトの着想にあたり、重要な技術的知見を共有してくださった もっくん 様（参考記事）に深く感謝いたします。