objective-c - 我在一个线程里起了一个runloop,开启了一个timer,但我发现页面返回时不走dealloc，timer无法停止,求大神帮助

问题描述

#import 'MyViewController.h'@interface MyViewController (){ NSTimer *_timer;}@end@implementation MyViewController- (void)dealloc{ [_timer invalidate];}- (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view._timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(changeCountdownTime) userInfo:nil repeats:YES]; [[NSRunLoop currentRunLoop] addTimer:_timer forMode:NSRunLoopCommonModes];}- (void)changeCountdownTime{ // do something}- (void)back{ [self.navigationController popViewControllerAnimated:YES];}

问题解答

推荐写法是在 viewWillAppear: 中先写 [_timer invalidate]; 然后写 _timer = nil; 之后才会销毁 vc 然后调用 -dealloc 方法。