A Windows Application With An Encrypted HTML User Interface: Part 1

Introduction
Main Program
Internet Explorer
Microsoft Edge
Summary
Author: Steve, 17th November 2021

Microsoft Edge

To embed Microsoft Edge into our container window we use the WebView2 control. Unfortunately, embedding Edge will not work out-of-the-box so we have to do a little preliminary work. We'll put our Edge implementation code in a CWebBrowser derived class called CEdge and define the four pure virtual functions to make the class concrete.

As a side note, I must say that I found it difficult to find good documentation from Microsoft about the steps that needed to be taken to get this to work and, as a result, this was a process with more pain than was reasonable given the small amount of code involved.

Prerequisites

To build and run the example, the following must be installed:

Visual Studio

Creating the Browser Control

The browser control is created asynchronously by first creating a WebView2 environment and then creating a WebView2 controller, from which a WebView2 window can be obtained.

The method to create the environment, CreateCoreWebView2EnvironmentWithOptions, is the most fraught with danger. It is this function which attempts to find the Edge WebView2 runtime and if it fails, it will return ERROR_FILE_NOT_FOUND. I just check whether it succeeded or not, but you may want to check for that specific return value.

Assuming all went well, the CEdge::OnCreateEnvironmentCompleted callback will be invoked, which takes the environment instance and calls CreateCoreWebView2Controller, passing another function to be called on success. That callback is where we get the WebView2 window to allow us to implement the Navigate and Refresh functions.

Navigation

Navigation in the CEdge class has to work slightly differently to the way it works in the Internet Explorer implementation. The issue is that the message loop must be running before we can get the WebView2 window, which implements the Navigate function. The main program calls CWebBrowser::Navigate to set the URL before we enter the message loop. To solve this, CEdge::Navigate checks whether the WebView2 window is available and, if not, it assumes that OnCreateCoreWebView2ControllerCompleted has not been called and stores the URL for later use in that function. If the WebView2 window has been created, then we call its Navigate function immediately.

Refresh and RunMessageLoop Functions

The Refresh and RunMessageLoop functions are trivially implemented. Refresh is simply a wrapper for the WebView2 window Reload function and RunMessageLoop implements textbook Windows message loop code without the need for any in-place active object.

If everything works, you should see something like this.

Embedded Edge