swift - 区分 Swift 按钮的更好方法？

Question

@IBAction func followUser(_ sender: Any) {
    if followBtn.titleLabel?.text == "Follow"{
        print("will follow")
    } else if followBtn.titleLabel?.text == "Following"{
    }
}

有更好的方法吗？我有一个在加载时运行的函数，然后检查用户是否被关注并更改按钮的文本。当然，如果按钮说“关注”，它将具有与说“关注”的按钮不同的功能。这是我能做到的唯一方法吗？感觉不对。

func checkFollowing(){

    let url = URL(string: "xxx")

    //request to this file
    var request = URLRequest(url: url!)

    //method to pass data
    request.httpMethod = "POST"

    //body to be appended to url
    let body = "id=\(user?["id"] as! String)&follower_id=\(imageID)"
    request.httpBody = body.data(using: String.Encoding.utf8)   //multi language support

    //launching
    URLSession.shared.dataTask(with: request, completionHandler: { (data:Data?, response:URLResponse?, error:Error?) in


        if error == nil{


            //communicate back to UI
            DispatchQueue.main.async(execute: {

                do{

                    //get json result
                    let json = try JSONSerialization.jsonObject(with: data!, options: JSONSerialization.ReadingOptions .mutableContainers) as?
                    NSDictionary

                    //assign json to a new var parseJSON in guard secured way
                    guard let parseJSON = json else{

                        print("error while parsing")
                        return
                    }


                    if parseJSON["status"] as! String == "1"{
                        self.followBtn.setTitle("Following", for: .normal)
                        self.followBtn.backgroundColor = UIColor(red: 32, green: 113, blue: 165, alpha: 0.5)
                    } else if parseJSON["status"] as! String == "0"{
                        self.followBtn.setTitle("Follow", for: .normal)
                    }


                } catch{

                    print("Caught an error: \(error)")

                }

            })

            //if unable to proceed with request

        } else{

            print("error: \(error)")


        }

        //launch prepared session
    }).resume()
}

Answer 1

通过 Controller 上的变量跟踪其状态将是更好的方法。

var isFollowing: Bool!

// -------------------------------

if parseJSON["status"] as! String == "1"{
    self.followBtn.setTitle("Following", for: .normal)
    self.followBtn.backgroundColor = UIColor(red: 32, green: 113, blue: 165, alpha: 0.5)
    self.isFollowing = true
} else if parseJSON["status"] as! String == "0"{
    self.followBtn.setTitle("Follow", for: .normal)
    self.isFollowing = false
}

// -------------------------------

@IBAction func followUser(_ sender: Any) {
    if self.isFollowing {
        // whatever happens when you're already following
    } else {
        print("will follow")
    }
}

(由您决定是否要将其设为可选、隐式解包可选，或设置默认值，但当然，如果您使用常规可选，则需要在最后一部分解包它)