试试这个。例如，您要打开一个Instagram应用程序：

    var instagramHooks = "instagram://user?username=johndoe"
    var instagramUrl = NSURL(string: instagramHooks)
    if UIApplication.sharedApplication().canOpenURL(instagramUrl!)
    {  
        UIApplication.sharedApplication().openURL(instagramUrl!)

     } else {
        //redirect to safari because the user doesn't have Instagram
        UIApplication.sharedApplication().openURL(NSURL(string: "http://instagram.com/")!)
    }