我使用这段代码：

let svcWWW : NSURL = NSURL(string: "https://www.facebook.com/radioNED/")!
let svcFB : NSURL = NSURL(string: "fb://profile/1238133072954301/")!
        
if (UIApplication.shared.canOpenURL(svcFB as URL)) {
            
    UIApplication.shared.open(svcFB as URL, options: convertToUIApplicationOpenExternalURLOptionsKeyDictionary([:]), completionHandler: nil)
            
} else {
            
    UIApplication.shared.open(svcWWW as URL, options: convertToUIApplicationOpenExternalURLOptionsKeyDictionary([:]), completionHandler: nil)
            
}

如果可用，它会打开Facebook应用程序。否则它会打开Safari并加载Facebook网页。
我希望这对你有帮助;）