iOS弹窗UIAlertAction用法

 UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"确认" message:@"确认删除吗？" preferredStyle:UIAlertControllerStyleAlert];

     UIAlertAction *action1 = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleDestructive handler:^(UIAlertAction * _Nonnull action) {
         //取消处理
     }];

     UIAlertAction *action2 = [UIAlertAction actionWithTitle:@"确认" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
         //确认处理
     }];

     [alert addAction:action1];
     [alert addAction:action2];
     [self.navigationController presentViewController:alert animated:YES completion:nil];