interface ICoreWebView2ExperimentalEnvironment16

Note

This reference is no longer being maintained. For the latest API reference, see WebView2 API Reference.

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));