Question

我有3条通知：

NotificationCenter.default.post(name:NSNotification.Name("Notification1"), object: nil)
NotificationCenter.default.post(name:NSNotification.Name("Notification2"), object: nil)
NotificationCenter.default.post(name:NSNotification.Name("Notification3"), object: nil)

对于每个帖子，我在视图控制器中有一个不同的观察者

第一：NotificationCenter.default.addObserver(forName:NSNotification.Name("Notification1"), object: nil, queue: nil, using: updateUx)

第二：NotificationCenter.default.addObserver(forName:NSNotification.Name("Notification2"), object: nil, queue: nil, using: updateUx)

第三：NotificationCenter.default.addObserver(forName:NSNotification.Name("Notification3"), object: nil, queue: nil, using: updateUx)

updateUx func仅包含通知打印。

我只得到了我的第一个通知，我无法抓住另外两个，我不知道为什么。

Answer 1

添加您的观察者，如下所示：

NotificationCenter.default.addObserver(self, selector: #selector(updateUx), name: NSNotification.Name("Notification1"), object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(updateUx), name: NSNotification.Name("Notification2"), object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(updateUx), name: NSNotification.Name("Notification3"), object: nil)

你很高兴。

编辑：完整的源代码（此项目在视图中有UIButton，@IBAction在故事板中与它相连。点击该按钮后，所有3个通知都会这个日志应该在控制台中打印三次

class ViewController: UIViewController {

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        NotificationCenter.default.addObserver(self, selector: #selector(updateUx), name: NSNotification.Name("Notification1"), object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(updateUx), name: NSNotification.Name("Notification2"), object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(updateUx), name: NSNotification.Name("Notification3"), object: nil)
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        NotificationCenter.default.removeObserver(self)
    }

    @IBAction func abc (_ sender: UIButton) {
        NotificationCenter.default.post(name:NSNotification.Name("Notification1"), object: nil)
        NotificationCenter.default.post(name:NSNotification.Name("Notification2"), object: nil)
        NotificationCenter.default.post(name:NSNotification.Name("Notification3"), object: nil)
    }

    func updateUx(){
        print("received...")
    }
}

NotificationCenter swift3无法观察帖子

1 个答案: