NSTimer为了保证参数的生命周期，NSTimer会对target对象retain一次强引用。这样即便target销毁了，定时器还能正常调用timeEvent。因为定时器要加到RunLoop中，所以RunLoop强引用着NSTimer，一般情况下你的target就是当前的控制器，如果你想让控制器如你所愿的销毁了，首先得销毁NSTimer。不然NSTimer强引用着self，self就无法销毁，从而导致内存泄漏。
GCDTimer
#import
@interface JX_GCDTimerManager : NSObject
+ (JX_GCDTimerManager *)sharedInstance;
/**
启动一个timer，默认精度为0.01秒。
@param timerName timer的名称，作为唯一标识。
@param interval 执行的时间间隔。
@param queue timer将被放入的队列，也就是最终action执行的队列。传入nil将自动放到一个子线程队列中。
@param repeats timer是否循环调用。
@param fireInstantly timer的第一次执行是否立刻触发，否则会等待interval的时长才会第一次执行。
@param action 时间间隔到点时执行的block。
*/
- (void)scheduledDispatchTimerWithName:(NSString *)timerName
timeInterval:(double)interval
queue:(dispatch_queue_t)queue
repeats:(BOOL)repeats
fireInstantly:(BOOL)fireInstantly
action:(dispatch_block_t)dispatchBlock;
/**
撤销某个timer。
@param timerName timer的名称，作为唯一标识。
*/
- (void)cancelTimerWithName:(NSString *)timerName;
/**
* 是否存在某个名称标识的timer。
*
* @param timerName timer的唯一名称标识。
* @param 查询结束回调。doExist==YES表示存在，反之。
*/
- (void)checkExistTimer:(NSString *)timerName
completion:(void (^)(BOOL doExist))completion;
@end
#import "JX_GCDTimerManager.h"
@interface JX_GCDTimerManager()
@property (nonatomic, strong) NSMutableDictionary *timerContainer;
@property (nonatomic, strong) dispatch_queue_t queue;
@end
@implementation JX_GCDTimerManager
#pragma mark - Public Method
+ (JX_GCDTimerManager *)sharedInstance {
static JX_GCDTimerManager *_gcdTimerManager = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken,^{
_gcdTimerManager = [[JX_GCDTimerManager alloc] init];
});
return _gcdTimerManager;
}
- (instancetype)init {
self = [super init];
if (self) {
dispatch_queue_attr_t attr = dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_CONCURRENT, QOS_CLASS_USER_INITIATED, 0);
dispatch_queue_t queue = dispatch_queue_create("com.JX_GCDTimerManager.queue", attr);
_queue = queue;
_timerContainer = [NSMutableDictionary new];
}
return self;
}
- (void)scheduledDispatchTimerWithName:(NSString *)timerName
timeInterval:(double)interval
queue:(dispatch_queue_t)queue
repeats:(BOOL)repeats
fireInstantly:(BOOL)fireInstantly
action:(dispatch_block_t)dispatchBlock {
if (!timerName || timerName.length == 0 || !dispatchBlock) return;
if (nil == queue)
queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_barrier_async(self.queue, ^{
dispatch_source_t timer = [self.timerContainer objectForKey:timerName];
if (!timer) {
timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, queue);
[self.timerContainer setObject:timer forKey:timerName];
dispatch_resume(timer);
}
if (repeats && fireInstantly) {
dispatch_async(queue, dispatchBlock);
}
dispatch_source_set_timer(timer, dispatch_time(DISPATCH_TIME_NOW, interval * NSEC_PER_SEC), interval * NSEC_PER_SEC, 0.01 * NSEC_PER_SEC);
dispatch_source_set_event_handler(timer, ^{
if (!repeats) {
[self.timerContainer removeObjectForKey:timerName];
dispatch_source_cancel(timer);
}
dispatchBlock();
});
});
}
- (void)cancelTimerWithName:(NSString *)timerName {
dispatch_barrier_async(self.queue, ^{
dispatch_source_t timer = [self.timerContainer objectForKey:timerName];
if (!timer) {
return;
}
[self.timerContainer removeObjectForKey:timerName];
dispatch_source_cancel(timer);
});
}
- (void)checkExistTimer:(NSString *)timerName completion:(void (^)(BOOL))completion {
dispatch_async(self.queue, ^{
if ([self.timerContainer objectForKey:timerName]) {
completion(YES);
} else {
completion(NO);
}
});
}
#import
@interface NSTimer (Secure)
/// 默认 repeats
+ (instancetype _Nullable)seScheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id _Nonnull)aTarget selector:(SEL _Nonnull)aSelector;
+ (instancetype _Nullable)seScheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id _Nonnull)aTarget selector:(SEL _Nonnull)aSelector repeats:(BOOL)yesOrNo;
/// 默认 repeats
+ (instancetype _Nullable)seScheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id _Nonnull)aTarget block:(void (^_Nonnull)(void))block;
+ (instancetype _Nullable)seScheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id _Nonnull)aTarget repeats:(BOOL)yesOrNo block:(void (^_Nonnull)(void))block;
@end
#import "NSTimer+Secure.h"
@interface SeTimerTarget: NSObject
@property (nonatomic, weak) id target;
@property (nonatomic, assign) SEL selector;
@property (nonatomic, weak) NSTimer *timer;
@property (nonatomic, copy) void(^block)(void);
@end
@implementation SeTimerTarget
- (void)seTimerTargetAction:(NSTimer *)timer {
if (self.target) {
IMP imp = [self.target methodForSelector:self.selector];
void (*func)(id, SEL, NSTimer*) = (void *)imp;
func(self.target, self.selector, timer);
}
else {
[self.timer invalidate];
self.timer = nil;
}
}
- (void)seTimerBlockAction:(NSTimer *)timer {
if (self.target && self.block) {
self.block();
}
else {
[self.timer invalidate];
self.timer = nil;
}
}
- (void)dealloc {
NSLog(@"==== timer dealloc ====");
}
@end
@implementation NSTimer (Secure)
+ (instancetype)seScheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id)aTarget selector:(SEL)aSelector {
return [self seScheduledTimerWithTimeInterval:ti target:aTarget selector:aSelector repeats:YES];
}
+ (instancetype)seScheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id)aTarget selector:(SEL)aSelector repeats:(BOOL)yesOrNo {
SeTimerTarget *timerTarget = [[SeTimerTarget alloc] init];
NSTimer *timer = [NSTimer timerWithTimeInterval:ti target:timerTarget selector:@selector(seTimerTargetAction:) userInfo:nil repeats:yesOrNo];
timerTarget.target = aTarget;
timerTarget.selector = aSelector;
timerTarget.timer = timer;
[[NSRunLoop mainRunLoop] addTimer:timerTarget.timer forMode:NSRunLoopCommonModes];
return timerTarget.timer;
}
+ (instancetype)seScheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id)aTarget block:(void (^)(void))block {
return [self seScheduledTimerWithTimeInterval:ti target:aTarget repeats:YES block:block];
}
+ (instancetype)seScheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id)aTarget repeats:(BOOL)yesOrNo block:(void (^)(void))block {
SeTimerTarget *timerTarget = [[SeTimerTarget alloc] init];
timerTarget.block = block;
timerTarget.target = aTarget;
NSTimer *timer = [NSTimer timerWithTimeInterval:ti target:timerTarget selector:@selector(seTimerBlockAction:) userInfo:nil repeats:yesOrNo];
timerTarget.timer = timer;
[[NSRunLoop mainRunLoop] addTimer:timerTarget.timer forMode:NSRunLoopCommonModes];
return timerTarget.timer;
}
@end
下面代码作者是winter找不到GitHub上的链接
这是我错误瞎使用来着 先记录下来