interface ICoreWebView2DevToolsProtocolEventReceiver

Article
04/10/2023

Note

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

interface ICoreWebView2DevToolsProtocolEventReceiver
  : public IUnknown

A Receiver is created for a particular DevTools Protocol event and allows you to subscribe and unsubscribe from that event.

Summary

Members	Descriptions
add_DevToolsProtocolEventReceived	Subscribe to a `DevToolsProtocol` event.
remove_DevToolsProtocolEventReceived	Remove an event handler previously added with `add_DevToolsProtocolEventReceived`.

Obtained from the WebView object using GetDevToolsProtocolEventReceiver.

Applies to

Product	Introduced
WebView2 Win32	0.9.430
WebView2 Win32 Prerelease	0.9.488

Members

add_DevToolsProtocolEventReceived

Subscribe to a DevToolsProtocol event.

public HRESULT add_DevToolsProtocolEventReceived(ICoreWebView2DevToolsProtocolEventReceivedEventHandler * handler, EventRegistrationToken * token)

The Invoke method of the handler runs whenever the corresponding DevToolsProtocol event runs. Invoke runs with an event args object containing the parameter object of the DevTools Protocol event as a JSON string.

// Prompt the user to name a CDP event, and then subscribe to that event.
void ScriptComponent::SubscribeToCdpEvent()
{
    TextInputDialog dialog(
        m_appWindow->GetMainWindow(),
        L"Subscribe to CDP Event",
        L"CDP event name:",
        L"Enter the name of the CDP event to subscribe to.\r\n"
            L"You may also have to call the \"enable\" method of the\r\n"
            L"event's domain to receive events (for example \"Log.enable\").\r\n",
        L"Log.entryAdded");
    if (dialog.confirmed)
    {
        std::wstring eventName = dialog.input;
        wil::com_ptr<ICoreWebView2DevToolsProtocolEventReceiver> receiver;
        CHECK_FAILURE(
            m_webView->GetDevToolsProtocolEventReceiver(eventName.c_str(), &receiver));

        // If we are already subscribed to this event, unsubscribe first.
        auto preexistingToken = m_devToolsProtocolEventReceivedTokenMap.find(eventName);
        if (preexistingToken != m_devToolsProtocolEventReceivedTokenMap.end())
        {
            CHECK_FAILURE(receiver->remove_DevToolsProtocolEventReceived(
                preexistingToken->second));
        }

        CHECK_FAILURE(receiver->add_DevToolsProtocolEventReceived(
            Callback<ICoreWebView2DevToolsProtocolEventReceivedEventHandler>(
                [this, eventName](
                    ICoreWebView2* sender,
                    ICoreWebView2DevToolsProtocolEventReceivedEventArgs* args) -> HRESULT 
                {
                    wil::unique_cotaskmem_string parameterObjectAsJson;
                    CHECK_FAILURE(args->get_ParameterObjectAsJson(&parameterObjectAsJson));
                    std::wstring title = eventName;
                    std::wstring details = parameterObjectAsJson.get();
                    wil::com_ptr<ICoreWebView2DevToolsProtocolEventReceivedEventArgs2> args2;
                    if (SUCCEEDED(args->QueryInterface(IID_PPV_ARGS(&args2))))
                    {
                        wil::unique_cotaskmem_string sessionId;
                        CHECK_FAILURE(args2->get_SessionId(&sessionId));
                        if (sessionId.get() && *sessionId.get())
                        {
                            title = eventName + L" (session:" + sessionId.get() + L")";
                            std::wstring targetId = m_devToolsSessionMap[sessionId.get()];
                            std::wstring targetLabel = m_devToolsTargetLabelMap[targetId];
                            details = L"From " + targetLabel + L" (session:" + sessionId.get() +
                                      L")\r\n" + details;
                        }
                    }
                    m_appWindow->AsyncMessageBox(details, L"CDP Event Fired: " + title);
                    return S_OK;
                })
                .Get(),
            &m_devToolsProtocolEventReceivedTokenMap[eventName]));
    }
}

remove_DevToolsProtocolEventReceived

Remove an event handler previously added with add_DevToolsProtocolEventReceived.

public HRESULT remove_DevToolsProtocolEventReceived(EventRegistrationToken token)

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