interface ICoreWebView2ExperimentalEnvironment16

Note

This an experimental API that is shipped with our prerelease SDK. See WebView2 release notes.

interface ICoreWebView2ExperimentalEnvironment16
  : public IUnknown

This is the ICoreWebView2Environment Experimental interface for creating a diagnostic monitor.

Summary

Members	Descriptions
CreateDiagnosticMonitor	Creates a new diagnostic monitor.

Applies to

Product	Introduced
WebView2 Win32	N/A
WebView2 Win32 Prerelease	1.0.4181

Members

CreateDiagnosticMonitor

Creates a new diagnostic monitor.

public HRESULT CreateDiagnosticMonitor(ICoreWebView2ExperimentalDiagnosticMonitor ** value)

The monitor receives diagnostic signals from all layers - WebView, Profile, and Environment - that match its filters.

Multiple monitors can coexist, each with its own filters and event handlers. This enables independent consumers such as a telemetry pipeline and a debug panel to operate without interfering with each other.

The monitor is active immediately, but no events fire until a filter is set via SetDiagnosticFilter.

Release the monitor to stop receiving events and free resources.

    // Create the monitor.
    wil::com_ptr<ICoreWebView2ExperimentalDiagnosticMonitor> monitor;
    HRESULT hr = m_environment16->CreateDiagnosticMonitor(&monitor);
    if (FAILED(hr))
    {
        std::wstringstream ss;
        ss << L"CreateDiagnosticMonitor failed: 0x" << std::hex << hr;
        MessageBox(
            m_appWindow->GetMainWindow(), ss.str().c_str(), L"Diagnostic Monitor",
            MB_OK | MB_ICONERROR);
        return;
    }

    // Set filter for NETWORK_REQUEST category.
    hr = monitor->SetDiagnosticFilter(
        COREWEBVIEW2_DIAGNOSTIC_CATEGORY_NETWORK_REQUEST,
        jsonFilter.empty() ? L"" : jsonFilter.c_str());
    if (FAILED(hr))
    {
        std::wstringstream ss;
        ss << L"SetDiagnosticFilter failed: 0x" << std::hex << hr;
        MessageBox(
            m_appWindow->GetMainWindow(), ss.str().c_str(), L"Diagnostic Monitor",
            MB_OK | MB_ICONERROR);
        return;
    }

    // Register the event handler. Capture the monitor name for logging.
    std::wstring capturedName = monitorName;
    EventRegistrationToken token;
    CHECK_FAILURE(monitor->add_DiagnosticReceived(
        Callback<ICoreWebView2ExperimentalDiagnosticReceivedEventHandler>(
            [this, capturedName](
                ICoreWebView2ExperimentalDiagnosticMonitor* sender,
                ICoreWebView2ExperimentalDiagnosticReceivedEventArgs* args) -> HRESULT
            {
                COREWEBVIEW2_DIAGNOSTIC_CATEGORY category;
                CHECK_FAILURE(args->get_Category(&category));

                COREWEBVIEW2_DIAGNOSTIC_SCOPE scope;
                CHECK_FAILURE(args->get_Scope(&scope));

                INT64 timestamp = 0;
                CHECK_FAILURE(args->get_Timestamp(&timestamp));

                wil::unique_cotaskmem_string detailsJson;
                CHECK_FAILURE(args->get_DetailsAsJson(&detailsJson));

                m_totalEventCount++;

                // Pretty-print the JSON details for readability.
                std::wstring json = detailsJson.get();
                std::wstringstream pretty;
                int indent = 0;
                bool inString = false;
                wchar_t prevCh = 0;
                for (wchar_t ch : json)
                {
                    if (ch == L'"' && prevCh != L'\\')
                        inString = !inString;
                    if (inString)
                    {
                        pretty << ch;
                        prevCh = ch;
                        continue;
                    }
                    if (ch == L'{' || ch == L'[')
                    {
                        pretty << ch << L"\r\n";
                        indent += 2;
                        for (int i = 0; i < indent; ++i)
                            pretty << L' ';
                    }
                    else if (ch == L'}' || ch == L']')
                    {
                        pretty << L"\r\n";
                        indent -= 2;
                        for (int i = 0; i < indent; ++i)
                            pretty << L' ';
                        pretty << ch;
                    }
                    else if (ch == L',')
                    {
                        pretty << ch << L"\r\n";
                        for (int i = 0; i < indent; ++i)
                            pretty << L' ';
                    }
                    else
                    {
                        pretty << ch;
                    }
                    prevCh = ch;
                }

                std::wstringstream ss;
                ss << L"Event #" << m_totalEventCount << L"\r\n"
                   << L"Category: " << static_cast<int>(category) << L"  Scope: "
                   << static_cast<int>(scope) << L"  Timestamp (ms since UNIX epoch): "
                   << timestamp << L"\r\n\r\n"
                   << L"Details:\r\n"
                   << pretty.str();

                MessageBox(
                    m_appWindow->GetMainWindow(), ss.str().c_str(), capturedName.c_str(),
                    MB_OK | MB_ICONINFORMATION);

                return S_OK;
            })
            .Get(),
        &token));