比如用safari访问钉钉的主页，顶部会出现这样一个banner
这是怎么实现的呢？
其实苹果提供了这么一个接口，可以在浏览器中检测应用是否安装并链接到下载页或直接打开，在你的Html页面头里添加这样一行即可
<meta name="apple-itunes-app" content="app-id=myAppStoreID, affiliate-data=myAffiliateData, app-argument=myURL">
把其中的app-id替换成你的应用在市场上的id即可。
相关参数说明：
app-id: (Required.) Your app's unique identifier. To find your app ID from the iTunes Link Maker, type the name of your app in the Search field, and select the appropriate country and media type. In the results, find your app and select iPhone App Link in the column on the right. Your app ID is the nine-digit number in between id and ?mt.
affiliate-data: (Optional.) Your iTunes affiliate string, if you are an iTunes affiliate. If you are not, find out more about becoming an iTunes affiliate at http://www.apple.com/itunes/affiliates/.
app-argument: (Optional.) A URL that provides context to your native app. If you include this, and the user has your app installed, she can jump from your website to the corresponding position in your iOS app. Typically, it is beneficial to retain navigational context because:
If the user is deep within the navigational hierarchy of your website, you can pass the document’s entire URL, and then parse it in your app to reroute her to the correct location in your app.
If the user performs a search on your website, you can pass the query string so that she can seamlessly continue the search in your app without having to retype her query.
If the user is in the midst of creating content, you can pass the session ID to download the web session state in your app so she can nondestructively resume her work.
You can generate the app-argument of each page dynamically with a server-side script. You can format it however you'd like, as long as it is a valid URL.
