在 Swift 中调用 UIAlertController: 0x7ff211650140 时发出警告

Question

我有时会在致电UIAlert 时收到此警告

尝试加载视图控制器的视图 不允许解除分配，并可能导致未定义的行为 ()

code used:

    func alert (dictKey: String){
        print(dictKey)
        let alertController = UIAlertController(title: nil, message: promptsArr[dictKey], preferredStyle: .Alert )
        let OKAction = UIAlertAction(title: "OK", style: .Default) { (action) in

        }
        alertController.addAction(OKAction)
        if self.presentedViewController == nil {
            delay(1.0){
                self.presentViewController(alertController, animated: true, completion: nil)
            }
        } else {
            self.presentedViewController!
        }

Answer 1

1. 删除delay()

2. 把逻辑放在self.presentedViewController里面： （如果存在则无需创建警报）

   func alert (dictKey: String){
       if self.presentedViewController == nil {
           let alertController = UIAlertController(
               title: nil,
               message: promptsArr[dictKey],
               preferredStyle: .Alert )
           let OKAction = UIAlertAction(title: "OK", style: .Default) {
               (action) in
           }
           alertController.addAction(OKAction)
   
           self.presentViewController(
               alertController,
               animated: true,
               completion: nil)
       }
   }