If your (iOS 9.0 or later) app calls this method using a scheme you
have not declared,the method returns false,whether or not an
appropriate app for the scheme is installed on the device.
但是我想知道如果没有安装应用程序,或者如果安装了应用程序,Facebook应用程序如何成功地将用户指向应用程序？
Facebook无法列出LSApplicationQueriesSchemes中的所有应用程序！
谢谢
解决方法
Unlike this method,the openURL: method is not constrained by the
UIDefaultLaunchStoryboard requirement: If an app that handles a scheme
is installed on the device,the openURL: method works,whether or
not you have declared the scheme.
所以他们做如下：
1)尝试调用openURL：使用fb兼容的URL,例如fb [app-id]：//授权…直到它返回true(我已经检查过,他们调用了很多url,例如fb [ app-id] lite,fb [app-id] mac,fb [app-id] paid,fb [app-id] green等).如果成功,目标应用程序将打开.
2)如果呼叫openURL没有成功,他们尝试调用canOpenURL：http：//itunes.apple.com/app / … url,然后调用openURL：具有相同的URL.用户被重定向到App Store.
