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title WebView2 Control
parent WebView2 Package
nav_order 4

WebView2 Control

WebView2 control is the core component of twinBASIC WebView2 package, providing complete functionality for embedding Microsoft Edge WebView2 controls in Windows applications.

Class Information

Property Value
Class Name WebView2
Base Class ControlAlt
Interface IWindowsControl
COM Creatable Yes
Access Modifier Public
Icon /miscellaneous/ICONS/WebView2_48.png

Overview

WebView2 control is based on Microsoft Edge (Chromium) kernel, providing:

  • 🌐 Modern web content rendering
  • 🔄 Bidirectional communication with JavaScript
  • 📊 Complete encapsulation of WebView2 API
  • 🎯 Simple and easy-to-use event-driven model
  • 🚀 High-performance web application integration

Quick Start

Private Sub Form_Load()
    ' Note: All WebView21 member operations must be done after WebView21_Ready()
    ' WebView21.DocumentURL = "https://www.twinbasic.com"
End Sub

Private Sub WebView21_Ready()
    ' Set initial URL
    WebView21.DocumentURL = "https://www.twinbasic.com"
    Debug.Print "WebView2 is ready!"
End Sub

Private Sub WebView21_NavigationComplete(ByVal IsSuccess As Boolean, ByVal WebErrorStatus As Long)
    If IsSuccess Then
        Debug.Print "Navigation successful: " & WebView21.DocumentURL
    Else
        Debug.Print "Navigation failed: " & WebErrorStatus
    End If
End Sub

Properties Overview

Navigation Related

Property Type Description
DocumentURL String (Read-only) Current document URL
DocumentTitle String (Read-only) Current document title
CanGoBack Boolean (Read-only) Can go back
CanGoForward Boolean (Read-only) Can go forward

Display Related

Property Type Description
ZoomFactor Double Zoom factor (1.5 = 150%)
IsMuted Boolean Whether audio is muted
BackColor OLE_COLOR Background color when loading

Configuration Related

Property Type Description
EnvironmentOptions WebView2EnvironmentOptions Environment options configuration
UseDeferredEvents Boolean Whether to use deferred events
IsScriptEnabled Boolean Whether to enable JavaScript
IsWebMessageEnabled Boolean Whether to enable Web messages
AreDefaultScriptDialogsEnabled Boolean Whether to enable default script dialogs
AreDevToolsEnabled Boolean Whether to allow opening DevTools
AreDefaultContextMenusEnabled Boolean Whether to enable default right-click menu
IsZoomControlEnabled Boolean Whether to allow zooming
UserAgent String UserAgent string

Feature Support Properties

Property Description
SupportsNavigateCustomFeatures Whether custom navigation is supported
SupportsSuspendResumeFeatures Whether suspend/resume is supported
SupportsAudioFeatures Whether audio control is supported
SupportsPdfFeatures Whether PDF export is supported
SupportsTaskManagerFeatures Whether task manager is supported

💡 Tip: For detailed descriptions of all properties, please refer to WebView2 Properties Complete Documentation.

Methods Overview

Navigation Methods

Method Description
Navigate(uri) Navigate to specified URL
NavigateCustom(uri, method, headers, postData) Custom HTTP request navigation
NavigateToString(html) Load HTML string
GoBack() Go back
GoForward() Go forward
Reload() Refresh

JavaScript Interaction

Method Description
ExecuteScript(code) Execute JavaScript code
JsRun(funcName, args()) Synchronously call JS function
JsRunAsync(funcName, args()) Asynchronously call JS function
JsProp(propName) Get JS property value
PostWebMessage(message) Send message to JavaScript
AddObject(name, obj, deferred) Expose COM object to JavaScript
RemoveObject(name) Remove exposed object

Resource Management

Method Description
AddWebResourceRequestedFilter() Add resource request filter
RemoveWebResourceRequestedFilter() Remove filter
AddScriptToExecuteOnDocumentCreated() Add page load script

Advanced Features

Method Description
OpenDevToolsWindow() Open developer tools
CallDevToolsProtocolMethod() Call DevTools protocol method
Suspend() Suspend WebView2
Resume() Resume WebView2
PrintToPdf() Export to PDF
SetVirtualHostNameToFolderMapping() Set virtual host mapping

💡 Tip: For detailed descriptions and examples of all methods, please refer to WebView2 Methods Complete Documentation.

Events

Lifecycle Events

Event Description
Create() Fired before WebView2 control is created, used to configure EnvironmentOptions
Ready() Fired after WebView2 control creation completes and is ready
Error() Fired when an error occurs during initialization

Navigation Events

Event Description
NavigationStarting() Fired before navigation starts, can cancel navigation
NavigationComplete() Fired after navigation completes
SourceChanged() Fired when DocumentURL property is updated
DocumentTitleChanged() Fired when document title is updated
DOMContentLoaded() Fired after DOM document is fully loaded

User Interaction Events

Event Description
PermissionRequested() Fired when web page requests permissions
AcceleratorKeyPressed() Fired when shortcut key is pressed
UserContextMenu() Fired when user right-clicks (requires AreDefaultContextMenusEnabled = False)

Script and Message Events

Event Description
ScriptDialogOpening() Fired when script dialog opens (requires AreDefaultScriptDialogsEnabled = False)
JsAsyncResult() Asynchronous JavaScript call returns result
JsMessage() Fired when JavaScript sends message (via window.chrome.webview.postMessage)

Resource and Download Events

Event Description
WebResourceRequested() Fired when matching Web resource request occurs
DownloadStarting() Fired when download starts, can modify path or cancel

System Events

Event Description
ProcessFailed() Fired when external process fails
NewWindowRequested() Fired when new window is requested
SuspendCompleted() Suspend successful completion
SuspendFailed() Suspend failed
PrintToPdfCompleted() PDF print successful
PrintToPdfFailed() PDF print failed
DevToolsProtocolResponse() DevTools protocol response

💡 Tip: For detailed parameter and usage descriptions of each event, please refer to WebView2 Events Complete Documentation.

Usage Examples

Basic Usage

Private Sub Form_Load()
    ' Note: All WebView21 member operations must be done after WebView21_Ready()
End Sub

Private Sub WebView21_Ready()
    ' Set initial URL
    WebView21.DocumentURL = "https://www.twinbasic.com"
    Debug.Print "WebView2 is ready!"
End Sub

Private Sub WebView21_NavigationComplete(ByVal IsSuccess As Boolean, ByVal WebErrorStatus As Long)
    If IsSuccess Then
        Debug.Print "Navigation successful: " & WebView21.DocumentURL
    Else
        Debug.Print "Navigation failed: " & WebErrorStatus
    End If
End Sub

JavaScript Interaction

' Execute JavaScript code
WebView21.ExecuteScript "alert('Hello from VB6!')"

' Synchronously call JavaScript function
Dim title As String
title = WebView21.JsProp("document.title")
Me.Caption = title

' Asynchronously call JavaScript function
Dim token As LongLong
token = WebView21.JsRunAsync("fetchData", "api/data")

Private Sub WebView21_JsAsyncResult(ByVal Result As Variant, Token As LongLong, ErrString As String)
    If Token = token Then
        Debug.Print "Async return result: " & Result
    End If
End Sub

Receive JavaScript Messages

Private Sub WebView21_JsMessage(ByVal Message As Variant)
    If VarType(Message) = vbObject Then
        Dim msg As Object
        Set msg = Message
        If msg.Exists("type") And msg("type") = "alert" Then
            MsgBox msg("message")
        End If
    End If
End Sub

JavaScript side:

window.chrome.webview.postMessage({
  type: "alert",
  message: "Hello from JavaScript!",
});

Intercept Web Requests

Private Sub WebView21_Ready()
    ' Add resource filter
    WebView21.AddWebResourceRequestedFilter "*.js", wv2WebResourceContext.wv2All
End Sub

Private Sub WebView21_WebResourceRequested(ByVal Request As WebView2Request, _
                                          ByVal Response As WebView2Response)
    ' Block specific script
    If InStr(Request.Uri, "analytics.js") > 0 Then
        Response.StatusCode = 404
        Response.ReasonPhrase = "Not Found"
    End If
End Sub

PDF Export

Private Sub cmdExportPDF_Click()
    If WebView21.SupportsPdfFeatures Then
        WebView21.PrintToPdf "C:\Documents\export.pdf", _
                           wv2PrintOrientation.wv2PrintPortrait, _
                           , , , , , , , True
    Else
        MsgBox "PDF export not supported"
    End If
End Sub

Private Sub WebView21_PrintToPdfCompleted()
    MsgBox "PDF export successful!"
End Sub

Notes

  1. Runtime Requirement: System needs to have WebView2 Runtime (Evergreen) installed
  2. Ready Event: Can only call most methods after Ready event is triggered
  3. Thread Safety: Use UseDeferredEvents to avoid re-entrancy problems
  4. Memory Management: Release COM objects in time to avoid memory leaks
  5. Error Handling: Properly handle initialization failures in Error event

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