C # determine whether a user uses a browser and display the actual content or QR code accordingly,
When we look at some webpages, we will find such a feature: some pages can only be accessed in, if accessed on a computer, only the QR code of the current address is displayed. How to implement this using C? Let's take a look at the code.
First, we need to determine which browser the user is using, which requires Request. the UserAgent attribute. The difference is discovered by capturing the UserAgent of a browser and a common browser. Below are the UserAgent of several common browsers:
Browser: Mozilla/5.0 (Linux; U; Android 4.4.2; zh-cn; 2013022 Build/HM2013022) AppleWebKit/533.1 (KHTML, like Gecko) version/4.0 MQQBrowser/5.4 TBS/025438 Mobile Safari/533.1 MicroMessenger/6.2.0.54 _ r00009949.561 NetType/WIFI Language/zh_CN
Firefox: Mozilla/5.0 (Windows NT 6.3; WOW64; rv: 38.0) Gecko/20100101 Firefox/38.0
IE11: Mozilla/5.0 (Windows NT 6.3; WOW64; Trident/7.0; rv: 11.0) like Gecko
Google Chrome: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/43.0.2357.130 Safari/537.36
Compared with the UserAgent of the above four browsers, we can find that the most important thing about the browser's UserAgent is to include the red MicroMessenger above, so we can determine whether the user has used the browser:
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At this point, we can determine whether the user has used a browser. Next, we will start Step 2: generate a QR code when the user does not access the browser.
C # generate a QR code with a very useful plug-in:ThoughtWorks. QRCode. It is very simple to use. We download ThoughtWorks from the official website. QRCode. dll, reference it to our project, and then introduce ThoughtWorks to the page. QRCode. the Codec namespace can be used to generate a QR code:
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There is a div on the page to display the QR code prompt.
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Modify the browser judgment code above:
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Here we are all done. Let's take a look at the different effects of browsing this page in a common browser and a browser:
Effect of accessing on a Common Browser
Scan access results