NSTimer 不调用选择器或按时间间隔重复

NSTimer does not call selector or repeat in time interval

我是 objective-c 的新手,在使用 NSTimer 时遇到了问题。在通过开发游戏学习 objective-c 时,我尝试在 NSTimer 的帮助下使用左右按钮移动精灵。但是,似乎没有调用选择器。我搜索了堆栈溢出并找到了一些解决方案,但我见过的任何解决方案都不起作用。这是我的代码-

#import "GameViewController.h"

@interface GameViewController ()
@property (strong) UIImage *playerImage;
@property (strong) UIImageView *playerView;
@property (strong) NSTimer *moveTimer;
@property CGRect playerRect;
@property int count;
@end

@implementation GameViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.count=0;
    self.playerImage = [UIImage imageNamed:@"ship.png"];
    self.playerView = [[UIImageView alloc] initWithImage: self.
                       playerImage];
    self.playerRect = CGRectMake(50,400, 32,32);
    self.playerView.frame = self.playerRect;
    [self.view addSubview: self.playerView];

//   this timer calls selector
//    self.moveTimer = [NSTimer scheduledTimerWithTimeInterval:.03
//                                             target:self
//                                           selector:@selector(movePlayerRight:)
//                                           userInfo:nil
//                                            repeats:YES];
}

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


- (IBAction)moveLeft:(id)sender {
    [self releaseTouch];
    NSLog(@"Left Move");
//this timer does not call selector
    self.moveTimer = [NSTimer scheduledTimerWithTimeInterval:.03
                                                      target:self
                                           selector:@selector(movePlayerLeft:)
                                                    userInfo:nil
                                                     repeats:YES];
//    [[NSRunLoop mainRunLoop] addTimer:self.moveTimer forMode:NSDefaultRunLoopMode];
//    [[NSRunLoop mainRunLoop] run];
    //[self.moveTimer fire];
}

- (IBAction)moveRight:(id)sender {
    [self releaseTouch];
    NSLog(@"Right Move");
//    if(![NSThread isMainThread])
//        dispatch_async(dispatch_get_main_queue(), ^{
//this timer does not call selector
    self.moveTimer = [NSTimer scheduledTimerWithTimeInterval:.03
                                                      target:self
                                           selector:@selector(movePlayerRight:)
                                                    userInfo:nil
                                                     repeats:YES];

}

- (IBAction)TouchRelease:(id)sender {
    [self releaseTouch];
}

-(void) movePlayerRight:(NSTimer*)timer {
    NSLog(@"Right Move Selector");
    if(self.playerRect.origin.x <= 320){
        self.playerRect = CGRectOffset(self.playerRect, 3, 0);
        self.playerView.frame = self.playerRect;
    }
}
-(void) movePlayerLeft:(NSTimer*)timer {
    NSLog(@"Left Move Selector");
    if(self.playerRect.origin.x >= 10){
        self.playerRect = CGRectOffset(self.playerRect, -3, 0);
        self.playerView.frame = self.playerRect;
    }
}
-(void)releaseTouch{
    if(self.moveTimer != nil){
        [self.moveTimer invalidate];
        self.moveTimer = nil;
    }
}
@end

让我解释一下我的尝试。

  1. 我尝试使用 scheduledTimerWithTimeInterval,如代码所示。但是不行。
  2. 然后我尝试了 timerWithTimeInterval 然后 NSRunloop。没有 NSRunloop [moveTimer fire] 触发但 NSRunLoop 重复,它不会。
  3. 然后,在一个解决方案中,我发现,线程可能正在创建问题;所以,我尝试了-

    if(![NSThread isMainThread])
    dispatch_async(dispatch_get_main_queue(), ^{
    

    但是,线程不是这种情况,因为调试器不会进入“dispatch_async”行。

  4. 为了实际查看 NSTimer 的工作原理,我什至在“viewDidLoad”方法中 运行 并且它有效。

我做错了什么?

**解决方案:** 正如@Danil Valeev 和@aman.sood 所建议的那样,取消选中 Storyboard 自动布局,将 属性 更改为 'nonatomic';现在从计时器调用选择器:)

检查是否调用了 movePlayerRight: 或 movePlayerLeft:。并且视图中没有使用自动布局(我认为这是原因)。您可以在实用程序第一个选项卡的 xib/storyboard 文件中禁用自动布局。

将 [NSRunLoop mainRunLoop] 替换为 [NSRunLoop currentRunLoop] 它应该可以工作