Collection WeChat public platform QR Code, with WeChat scan to jump to the public platform interface, no use to jump download WeChat interface, this function is how to achieve

The collection sweep the common platform QR Code, uses the sweep to jump to the public platform interface, does not use to jump the download interface, how this function realizes?
Sweep the public platform QR code
Jump to the public platform interface if you have a fit
Jump Download Interface without loading
How is this feature implemented?

I'll check the QR code for the public platform.
The result is a URL, and the content is like this http://weixin.qq.com/r/RHU6NQjE1japhxlWnyBg
Encrypted URLs may have some parameters added to the judgment
is the principle of implementation possible?
Does the sweep use a specific parameter when it is submitted to the server to make certain judgments return a different value?

Trouble cattle people explain the way to achieve the point of pointing my brother ~ ~ ~

Thank you ~
------to solve the idea----------------------
I don't know how to read or play with this stuff, but the way you say it should be there.

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