问题描述
我正在编写一个简单的Chrome扩展程序，需要使用该行为来检测设备是否已连接到Internet.我目前正在尝试连接到ping服务以检查网络状态，但效率不高.我可以通过Chrome JavaScript API收听任何事件吗?
I'm writing a simple Chrome extension, the behavior is needed to detect if device is connect to the Internet. I'm currently trying to connect to ping service for checking network status and it is not efficient. Is there any event to which I can listen from Chrome JavaScript API?
推荐答案
中没有特定事件Chrome扩展API 旨在用于此目的.
在">如何检测在线/离线事件跨浏览器? "，建议您使用 和事件(来自MDN ):
In "How to detect online/offline event cross-browser?" it is suggested that you can use window.navigator.onLine and the events (from MDN):
window.addEventListener('offline', function(e) { console.log('offline'); });
window.addEventListener('online', function(e) { console.log('online'); });
但是，我在Windows 10 x64上使用Chrome版本56.0.2924.87(64位)进行的测试表明，这些都不是有效的.当物理断开网络电缆的连接时，事件不会在后台脚本或内容脚本中触发.此外，两个脚本中的window.navigator.onLine值均保持为true.重新插入网络电缆时，同样也没有活动.
However, my testing on Windows 10 x64 using Chrome Version 56.0.2924.87 (64-bit) indicated that none of those are valid. When the network cable was physically disconnected, the events did not fire in either the background script, nor a content script In addition, the value of window.navigator.onLine remained true in both. There was a similar lack of activity when the network cable was plugged back in.
但是，当网络电缆断开连接时，会触发 webRequest .特别是以下事件:
However, when the network cable was disconnected a webRequest was fired. Specifically the following events:
webRequest.onBeforeRequest -> arg[0]= Object { frameId: -1, method: "GET", parentFrameId: -1, requestId: "10787", tabId: -1, timeStamp: 1487550094371.293, type: "other", url: "https://www.google.com/searchdomaincheck?format=domain&type=chrome", __proto__: Object }
webRequest.onBeforeSendHeaders-> arg[0]= Object { frameId: -1, method: "GET", parentFrameId: -1, requestHeaders: Array[4], requestId: "10787", tabId: -1, timeStamp: 1487550094371.3901, type: "other", url: "https://www.google.com/searchdomaincheck?format=domain&type=chrome", __proto__: Object }
webRequest.onSendHeaders -> arg[0]= Object { frameId: -1, method: "GET", parentFrameId: -1, requestHeaders: Array[4], requestId: "10787", tabId: -1, timeStamp: 1487550094371.437, type: "other", url: "https://www.google.com/searchdomaincheck?format=domain&type=chrome", __proto__: Object }
webRequest.onErrorOccurred -> arg[0]= Object { error: "net::ERR_NAME_NOT_RESOLVED", frameId: -1, fromCache: false, method: "GET", parentFrameId: -1, requestId: "10787", tabId: -1, timeStamp: 1487550096326.291, type: "other", url: "https://www.google.com/searchdomaincheck?format=domain&type=chrome", __proto__: Object }
重新连接电缆时，将触发以下webRequests序列:
When the cable was reconnected, the following sequence of webRequests were fired:
webRequest.onBeforeRequest -> arg[0]= Object { frameId: -1, method: "GET", parentFrameId: -1, requestId: "10938", tabId: -1, timeStamp: 1487550516485.3562, type: "other", url: "https://www.google.com/searchdomaincheck?format=domain&type=chrome", __proto__: Object }
webRequest.onBeforeSendHeaders-> arg[0]= Object { frameId: -1, method: "GET", parentFrameId: -1, requestHeaders: Array[4], requestId: "10938", tabId: -1, timeStamp: 1487550516485.523, type: "other", url: "https://www.google.com/searchdomaincheck?format=domain&type=chrome", __proto__: Object }
webRequest.onSendHeaders -> arg[0]= Object { frameId: -1, method: "GET", parentFrameId: -1, requestHeaders: Array[4], requestId: "10938", tabId: -1, timeStamp: 1487550516485.565, type: "other", url: "https://www.google.com/searchdomaincheck?format=domain&type=chrome", __proto__: Object }
webRequest.onHeadersReceived -> arg[0]= Object { frameId: -1, method: "GET", parentFrameId: -1, requestId: "10938", responseHeaders: Array[12], statusCode: 200, statusLine: "HTTP/1.1 200"tabId: -1, timeStamp: 1487550518279.5378, type: "other", url: "https://www.google.com/searchdomaincheck?format=domain&type=chrome", __proto__: Object }
webRequest.onResponseStarted -> arg[0]= Object { frameId: -1, fromCache: false, ip: "216.58.193.68", method: "GET", parentFrameId: -1, requestId: "10938", responseHeaders: Array[12], statusCode: 200, statusLine: "HTTP/1.1 200", tabId: -1, timeStamp: 1487550518279.653type: "other"url: "https://www.google.com/searchdomaincheck?format=domain&type=chrome", __proto__: Object }
webRequest.onCompleted -> arg[0]= Object { frameId: -1, fromCache: false, ip: "216.58.193.68", method: "GET", parentFrameId: -1, requestId: "10938", responseHeaders: Array[12], statusCode: 200, statusLine: "HTTP/1.1 200", tabId: -1, timeStamp: 1487550518279.754type: "other"url: "https://www.google.com/searchdomaincheck?format=domain&type=chrome", __proto__: Object }
因此，看来要观看事件的最佳人选是 webRequest.onErrorOccurred 用于离线， webRequest.onCompleted 用于在线，两者都与网址:https://www.google.com/searchdomaincheck?format=domain&type=chrome.
So, it appears that good candidates for events to watch are webRequest.onErrorOccurred for going offline and webRequest.onCompleted for going online, both with the URL: https://www.google.com/searchdomaincheck?format=domain&type=chrome.
这将需要进一步测试.仅在上面提到的配置上进行过测试.
This would need further testing. It was only tested on the configuration mentioned above.
这篇关于如何检测Chrome扩展程序中的网络状态更改的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！