如何让 node-red 检测到 dashboard UI 页面已被访问，即有人正在查看该页面。
我这么说是因为我会比没有人访问时更频繁地向仪表板发送更新。我知道我可以实现 Websockets，但这将是我创建的页面，而不是仪表板 UI
I have looked everywhere, and in forums, no solutions offered besides create a custom webpage
最佳答案
发生这种情况时，ui_control 节点可用于发出消息。
从 ui_control 节点的信息侧边栏:
When any browser client connects or loses connection, or changes tab, this node will emit a
msgcontaining:
payload- connect, lost, or change.socketid- the ID of the socket (this will change every time the browser reloads the page).socketip- the ip address from where the connection originated.tab- the number of the tab. (Only for 'change' event).name- the name of the tab. (Only for 'change' event).
关于user-interface - Node-Red 检测仪表板页面访问，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/55690004/