< meta HTTP-EQUIV = "x-ua-compatible" content = Role of "ie=edge,chrome=1"/>

< meta HTTP-EQUIV = "x-ua-compatible" content = "ie=edge,chrome=1"/>

Introduced:
This is a special tag for IE8, used to specify IE8 browser to simulate the rendering of a particular version of IE (such as people annoying IE6), to solve some of the compatibility problems, such as the specific way to simulate IE7 as follows:

< = "x-ua-compatible" = "Ie=emulateie7"/>

But what makes me curious is that there is a value like chrome behind this tag, ie can also simulate chrome?
A quick search, only to understand that the original is not Microsoft enhanced IE, but Google did a plug-in: Google Chrome frame (google embedded browser framework GCF). This plugin can make the user's IE browser unchanged, but the user in the Web browsing, actually using the Google Chrome browser kernel, and support IE6, 7, 8 and other versions of IE browser, Google this corner digging real force! The meta tag mentioned above is used to specify that the page is rendered using the chrome kernel after the GCF is installed. gcf:http://code.google.com/intl/zh-cn/chrome/chromeframe/
Once the installation is complete, if you want to render a page using GCF, just precede the address of the page with GCF: Yes, for example: gcf:http://cooleep.com
But what if you want to specify the page default to use GCF for rendering at development time, and if the GCF is not installed and then rendered using the IE kernel?
is to use this tag.

Tag usage:
Read the next Chrome development document (http://www.chromium.org/developers/how-tos/chrome-frame-getting-started, need to FQ), below to briefly explain the syntax of this tag.

1. Most basic usage: add to the head of the page

< = "x-ua-compatible" = "chrome=1" >

to declare that the current page is rendered with the chrome kernel, What's more complicated is the usage that I saw at the beginning of this article:

<= "x-ua-compatible"= "ie=edge,chrome=1"/ >

The effect of this writing is that if the GCF is installed, a GCF is used to render the page, and if the GCF is installed, the highest version of the IE kernel is used for rendering.

2. Modify the HTTP header file method to enable the specified page to render using the GCF kernel:

In the HTTP header file, add the following information:

X-ua-compatible:chrome=1

In the Apache server, make sure that the mod_headers and mod_setenvif files are available, and then add the following configuration information to the httpd.conf:

<mod_setenvif.c><mod_headers.c>  browsermatch chromeframe gcfheader append x-ua-compatible "chrome=1" ENV=GCF  </ > </  >

on IIS7 or later servers, you only need to modify the Web. config file to add the following information:

<Configuration><system. WebServer><Httpprotocol><customheaders><Addname= "X-ua-compatible"value= "Chrome=1" /></customheaders></Httpprotocol></system.webserver></Configuration>

< meta HTTP-EQUIV = "x-ua-compatible" content = Role of "ie=edge,chrome=1"/>