NSTimer提供的timerWithTimeInterval:target:selector，该方法中target会对self进行强引用
self.timer = [NSTimer timerWithTimeInterval:1 target:weakSelf selector:@selector(fireHome) userInfo:nil repeats:YES];
[[NSRunLoop currentRunLoop] addTimer:self.timer forMode:NSRunLoopCommonModes];
解决方式1
self.timer =[NSTimer scheduledTimerWithTimeInterval:3 repeats:YES block:^(NSTimer * _Nonnull timer) {
}];
解决方法二：
使用VC中的didMoveToParentViewController释放timer
- (void)didMoveToParentViewController:(UIViewController *)parent{
// 无论push 进来 还是 pop 出去 正常跑
// 就算继续push 到下一层 pop 回去还是继续
if (parent == nil) {
[self.timer invalidate];
self.timer = nil;
NSLog(@"timer 走了");
}
}
解决方法三：
虚基类NSProxy
@interface LGProxy : NSProxy
+ (instancetype)proxyWithTransformObject:(id)object;
@end
#import "LGProxy.h"
@interface LGProxy()
@property (nonatomic, weak) id object;
@end
@implementation LGProxy
+ (instancetype)proxyWithTransformObject:(id)object{
LGProxy *proxy = [LGProxy alloc];
proxy.object = object;
return proxy;
}
// 通过消息转发机制，让实际的响应target还是外部self，这一步至关重要，主要涉及到runtime的消息机制。
// 转移
// 强引用 -> 消息转发
-(id)forwardingTargetForSelector:(SEL)aSelector {
return self.object;
}
@end
使用
-(void)viewDidLoad{
[super viewDidLoad];
self.proxy = [LGProxy proxyWithTransformObject:self];
self.timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self.proxy selector:@selector(fireHome) userInfo:nil repeats:YES];
}
- (void)dealloc{
// VC -> proxy <- runloop
[self.timer invalidate];
self.timer = nil;
NSLog(@"%s",__func__);
}
