Question

在我重新加载表之前，我想知道在后台保存的所有任务都已完成保存。在创建新PFQuery之前，我必须完成5个不同的object.saveInBackgroundWithBlock({ (Success: true, error) -> Void in count ++ })函数。我现在的想法是说：

if

然后，一旦计数达到一定数量就可以执行查询。我不想使用while count < 0 { continue } else if count == 5 { self.fetchSecondaryObjects() }，因为如果网络处理保存请求的时间过长。一段时间的陈述会有效吗？如：

var prefab : GameObject;
function Update () {
    if (Input.GetMouseButtonDown(0)) {
        var pos = Input.mousePosition;
        pos.z = transform.position.z - Camera.main.transform.position.z;
        pos = Camera.main.ScreenToWorldPoint(pos);
        var q = Quaternion.FromToRotation(Vector3.up, pos - transform.position);
        var go = Instantiate(prefab, transform.position, q);
        go.rigidbody2D.AddForce(go.transform.up * 20000.0);  
    }
}

理想情况下，我会使用实时数据引擎为我的应用程序供电，但我找不到一个可以使用的功能，因为我只能在Swift中编写。如果存在，你知道它，我很想知道它。

Answer 1

每次增量时都要进行检查。它的开销非常低，只有五个比较。

object.saveInBackgroundWithBlock({ (Success: true, error) -> Void in
  count ++;
  if count == 5 {
    self.fetchSecondaryObjects()
  }
})

除非我错过某些原因，否则你无法做到这一点，这似乎是最简单的解决方案。比运行无限循环更好。

Answer 2

一般情况下，我尝试不要在这种情况下使用，因为如果你的逻辑中存在某种情况，很容易陷入其中。你为什么不用这样的东西：

//
//  ViewController.h
//  CustomNavigationController
//
//  Created by Durul Dalkanat on 11/05/15.
//  Copyright (c) 2015 Durul Dalkanat. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController

- (IBAction)showLandscapeViewButtonClicked:(id)sender;

@end

//
//  ViewController.m
//  CustomNavigationController
//
//  Created by Durul Dalkanat on 11/05/15.
//  Copyright (c) 2015 Durul Dalkanat. All rights reserved.
//

#import "ViewController.h"
#import "LandscapeView.h"
#import "CustomNavigationControllerViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
  [super viewDidLoad];
  // Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning {
  [super didReceiveMemoryWarning];
  // Dispose of any resources that can be recreated.
}


- (IBAction)showLandscapeViewButtonClicked:(id)sender {

  LandscapeView *landscape = [[LandscapeView alloc]initWithNibName:@"LandscapeView" bundle:nil];
  CustomNavigationControllerViewController *nav = [[CustomNavigationControllerViewController alloc]initWithRootViewController:landscape];
  nav.navigationBarHidden = true;
  [self presentViewController:nav animated:YES completion:^{

  }];

}


#pragma mark handeling rotation

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
  return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation{
  return UIInterfaceOrientationPortrait;
}
- (BOOL)shouldAutorotate
{
  return NO;
}
- (NSUInteger)supportedInterfaceOrientations
{
  BOOL atLeastIOS6 = [[[UIDevice currentDevice] systemVersion] floatValue] >= 6.0;
  if(atLeastIOS6)
  {
    return UIInterfaceOrientationMaskPortrait;
  }
  else{
    return UIInterfaceOrientationPortrait;
  }
}


@end

And Insert a New ViewController with Xib. After please change freeform.

//
//  LandscapeView.h
//  CustomNavigationController
//
//  Created by Durul Dalkanat on 11/05/15.
//  Copyright (c) 2015 Durul Dalkanat. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface LandscapeView : UIViewController

@end
//
//  LandscapeView.m
//  CustomNavigationController
//
//  Created by Durul Dalkanat on 11/05/15.
//  Copyright (c) 2015 Durul Dalkanat. All rights reserved.
//

#import "LandscapeView.h"

@interface LandscapeView ()

@end

@implementation LandscapeView

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

/*

#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}
*/

@end

//
//  CustomNavigationControllerViewController.m
//
//
//  Created by Durul Dalkanat
//


#import <UIKit/UIKit.h>

@interface CustomNavigationControllerViewController : UINavigationController

@end

//
//  CustomNavigationControllerViewController.m
//
//
//  Created by Durul Dalkanat
//

#import "CustomNavigationControllerViewController.h"

@interface CustomNavigationControllerViewController ()

@end

@implementation CustomNavigationControllerViewController

- (NSUInteger)supportedInterfaceOrientations
{
    return UIInterfaceOrientationMaskLandscape;

}




@end

怎么说＆＃34;当计数到达这个数字时执行这个功能＆＃34;？

2 个答案: