I'm not sure if what you wants to do is to hava a button on your view or web page, where on click it opens wechat and allows users to share the content to other people?
If it is an mobile application, you may want to have a look at wechat's offical api document.
You would first need to do some applications to wechat, then they may give you permission to use this function by providing you with an appId, you utilize this appId and implement interfaces they provide to realize sharing functions.
If you have a wechat offical acount, or you wish to show your web application pages within the browser inside the wechat app (this is my understanding), then you would want to take a look here. You would first have to register an offical account, and bind your application domain in the settings page within the account.
If you have a PC website and wish for users to share certain pages to wechat. what you can do is generate a QR code for that link, thus when users scan the code with wechat's scan function, the link would be opened within the browser inside wechat, and allowing users to use all wechat functions such as sharing.