UIAlertController不使用Swift 3.0

6 回答

• 27

  像这样在Swift 3中更改了 presentViewController .

  present(alert, animated: true)
  

  有关详细信息，请查看Apple Documentation .

  从Swift 3 completion 是可选的，所以如果你不想处理完成块，则不需要为此编写 nil ，如果你想处理完成块，那么这样写 .

  self.present(alert, animated: true) { 
  
  }
  

  Note: 您的notifyUser方法是使用 static 声明的，因此您不能使用 self ，因此请删除它以删除更正此错误后得到的下一个错误 .

  回复于 2024-05-02T23:04:03+08:00
• 11

  let actionSheetController: UIAlertController = UIAlertController(title: "Action Sheet", message: "Swiftly Now! Choose an option!", preferredStyle: .alert)
   let cancelAction: UIAlertAction = UIAlertAction(title: "Cancel", style: .cancel) { action -> Void in
              //Just dismiss the action sheet
          }
   actionSheetController.addAction(cancelAction)
   self.present(actionSheetController, animated: true, completion: nil)
  

  回复于 2024-05-02T23:04:03+08:00
• 4

  斯威夫特3

  let alertView = UIAlertController(title: "", message: "your message", preferredStyle: .alert)
  let action = UIAlertAction(title: "OK", style: .default, handler: { (alert) in
  
  })
  alertView.addAction(action)
  self.present(alertView, animated: true, completion: nil)
  

  回复于 2024-05-02T23:04:03+08:00
• 2

  您试图在静态方法中使用self，而self应该是该类的当前实例，但static不能使用self .

  Without Action Handler For Alert Button

  In Obj-C

  +(void) notifyUser:(NSString *)title withMessage:(NSString *)message onViewController:(UIViewController *)vc {
      UIAlertController *alert = [UIAlertController alertControllerWithTitle:title message:message preferredStyle:UIAlertControllerStyleAlert];
      UIAlertAction *action = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleCancel handler:nil];
      [alert addAction:action];
      //vc will be the view controller on which you will present your alert as you cannot use self because this method is static.
      [vc presentViewController:alert animated:true completion:nil];
  }
  

  In Swift 3.0

  static func notifyUser(_ title: String, message: String, vc: UIViewController) -> Void
      {
          let alert = UIAlertController(title: title,
                                        message: message,
                                        preferredStyle: UIAlertControllerStyle.alert)
  
          let cancelAction = UIAlertAction(title: "OK",
                                           style: .cancel, handler: nil)
  
          alert.addAction(cancelAction)
          //vc will be the view controller on which you will present your alert as you cannot use self because this method is static.
          vc.present(alert, animated: true, completion: nil)
      }
  

  With Action Handler For Alert Button

  In Obj-C

  +(void) notifyUser:(NSString *)title withMessage:(NSString *)message withButtonTitles:(NSArray<NSString *> *)buttonTitles andButtonStyles:(NSArray *)styles onViewController:(UIViewController *)vc onCompletion:(void (^)(NSInteger))completion  {
      UIAlertController *alert = [UIAlertController alertControllerWithTitle:title message:message preferredStyle:UIAlertControllerStyleAlert];
  
      for (NSString *title in buttonTitles) {
          UIAlertActionStyle style = [[styles objectAtIndex:[buttonTitles indexOfObject:title]] intValue];
  
          UIAlertAction *actionObj = [UIAlertAction actionWithTitle:title style:style handler:^(UIAlertAction *action){
              NSInteger index = [buttonTitles indexOfObject:action.title];
              completion(index);
          }];
          [alert addAction:actionObj];
      }
      //vc will be the view controller on which you will present your alert as you cannot use self because this method is static.
      [vc presentViewController:alert animated:true completion:nil];
  }
  

  像这样调用上面的实例方法 .

  [ClassName notifyUser:@"Title For Alert" withMessage:@"Message for Alert" withButtonTitles:@[@"Camera",@"Library",@"Dismiss"] andButtonStyles:@[@(UIAlertActionStyleDefault),@(UIAlertActionStyleDefault),@(UIAlertActionStyleCancel)] onViewController:yourViewController onCompletion:^(NSInteger indexOfTappedButton){
                      //Note the index of the button will have the same order as you have provide the titles array in this method
      }];
  

  此处，yourViewController是您将在其上显示此警报的控制器

  In Swift 3.0

  extension UIAlertController {
      static func notifyUser(_ title: String, message: String, alertButtonTitles: [String], alertButtonStyles: [UIAlertActionStyle], vc: UIViewController, completion: @escaping (Int)->Void) -> Void
      {
          let alert = UIAlertController(title: title,
                                        message: message,
                                        preferredStyle: UIAlertControllerStyle.alert)
  
          for title in alertButtonTitles {
              let actionObj = UIAlertAction(title: title,
                                            style: alertButtonStyles[alertButtonTitles.index(of: title)!], handler: { action in
                                              completion(alertButtonTitles.index(of: action.title!)!)
              })
  
              alert.addAction(actionObj)
          }
  
  
          //vc will be the view controller on which you will present your alert as you cannot use self because this method is static.
          vc.present(alert, animated: true, completion: nil)
      }
  }
  

  像这样调用上面的静态方法 .

  UIAlertController.notifyUser("Title for Alert", message: "Message show in Alert", alertButtonTitles: ["Camera", "Library","Dismiss"], alertButtonStyles: [.default,.default,.cancel], vc: yourViewController, completion: { indexOfTappedButton in
              //Note the index of the button will have the same order as you have provide the titles array in this method
          })
  

  此处，yourViewController是您将在其上显示此警报的控制器

  回复于 2024-05-02T23:04:03+08:00
• 27

  Swift 3 尝试 Custom 操作取消

  let uiAlertController = UIAlertController(// create new instance alert  controller
            title: "You TITLE text",
            message: "You Message text", 
            preferredStyle:.alert)
  
      uiAlertController.addAction(// add Custom action on Event is Cancel
      UIAlertAction.init(title: "Cancel", style: .default, handler: { (UIAlertAction) in
         //TO DO code
         uiAlertController.dismiss(animated: true, completion: nil)//dismiss show You alert, on click is Cancel
      }))
      //show You alert
      self.present(uiAlertController, animated: true, completion: nil)
  

  回复于 2024-05-02T23:04:03+08:00
• 0

  let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertControllerStyle.alert)
  if action {
      alert.addAction(UIAlertAction(title: "Ok", style: .default, handler: {
          (action : UIAlertAction!) in self.navigationController?.popViewController(animated: true)
      }))
  } else {
      alert.addAction(UIAlertAction(title: "Ok", style: .default, handler: nil))
  }
  self.present(alert, animated: true, completion: nil)
  

  回复于 2024-05-02T23:04:03+08:00