//显示弹出框列表选择
   UIAlertController* alert = [UIAlertController   alertControllerWithTitle:@"Title"
       message:@"This is an Sheet."
       preferredStyle:UIAlertControllerStyleActionSheet];

   UIAlertAction* cancelAction = [UIAlertAction
                                  actionWithTitle:@"取消"
                                  style:UIAlertActionStyleCancel
                                  handler:^(UIAlertAction * action) {
                                      //响应事件
                                      NSLog(@"action = %@", action);
                                  }];
   UIAlertAction* deleteAction = [UIAlertAction
                                  actionWithTitle:@"删除" style:UIAlertActionStyleDestructive
                                  handler:^(UIAlertAction * action) {
                                      //响应事件
                                      NSLog(@"action = %@", action);
                                  }];
   UIAlertAction* saveAction = [UIAlertAction actionWithTitle:@"保存" style:UIAlertActionStyleDefault
                                                      handler:^(UIAlertAction * action) {
                                                          //响应事件
                                                          NSLog(@"action = %@", action);
                                                      }];
   [alert addAction:saveAction];
   [alert addAction:cancelAction];
   [alert addAction:deleteAction];
   [self presentViewController:alert animated:YES completion:nil];




UIAlertController* alert = [UIAlertController alertControllerWithTitle:@"Title"
                                                                    message:@"This is an alert."
                                                             preferredStyle:UIAlertControllerStyleAlert];

     UIAlertAction* defaultAction = [UIAlertAction
                                     actionWithTitle:@"OK"
                                     style:UIAlertActionStyleDefault
                                     handler:^(UIAlertAction * action) {
                                         //响应事件
                                         NSLog(@"OK");
                                     }];

     UIAlertAction* cancelAction = [UIAlertAction            actionWithTitle:@"Cancel"
          style:UIAlertActionStyleDefault
         handler:^(UIAlertAction * action) {
           //响应事件
      NSLog(@"CANCEL");
     }];

     [alert addAction:defaultAction];
     [alert addAction:cancelAction];
     [self presentViewController:alert animated:YES completion:nil];