PHP + Ajax real-time automatic detection of networking

PHP + Ajax real-time automatic detection of networking

This article describes how to automatically detect the connection of PHP and Ajax in real time. Share it with you for your reference. The specific implementation method is as follows:

Some html code:

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<! DOCTYPE html PUBLIC "-// W3C // dtd xhtml 1.0 Transitional // EN" Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd> <Html xmlns = "http://www.w3.org/1999/xhtml"> <Head> <Title> PHP + Ajax real-time automatic detection of networking </title> <Meta http-equiv = "Content-Type" content = "text/html; charset = UTF-8"> <Script type = "text/javascript"> <! -- Var xmlHttp; Function createXMLHttpRequest (){ If (window. ActiveXObject ){ XmlHttp = new ActiveXObject ("Microsoft. XMLHTTP "); } Else if (window. XMLHttpRequest ){ XmlHttp = new XMLHttpRequest (); } } Function start (){ CreateXMLHttpRequest (); Var url = "getNetLink "; XmlHttp. open ("GET", url, true ); XmlHttp. onreadystatechange = callback; XmlHttp. send (null ); } Function callback (){ If (xmlHttp. readyState = 4 ){ If (xmlHttp. status = 200 ){ Document. getElementById ("shownetlink"). innerHTML = xmlHttp. responseText; SetTimeout ("start ()", 8000 ); } } } // --> </Script> </Head> <Body onload = "start ();"> <H1> PHP + Ajax real-time automatic detection of networking <P> current network status: <span id = "shownetlink"> </span> </p> </Body> </Html>

Php code:

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Public function getNetLink (){ Header ("cache-control: no-cache, must-revalidate "); Header ("Content-Type: text/html; charset = UTF-8 "); $ File = fopen ("http://www.baidu.com/", "r "); If (! $ File ){ $ Shownetlink = "<font color = \" red \ "> network connection failed </font> "; } Else { $ Shownetlink = "<font color = \" # 06C \ "> normal network connection </font> "; } Echo $ shownetlink; }

I hope this article will help you with php programming.