iOS Developer

RunLoop

2017-02-15  本文已影响29人  45b645c5912e

什么是RunLoop

main函数中的RunLoop

int main(int argc, char * argv[]) {
    @autoreleasepool {
        return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
    }
}

RunLoop对象

RunLoop与线程

获得RunLoop对象

[NSRunLoop currentRunLoop]; // 获得当前线程的RunLoop对象
[NSRunLoop mainRunLoop]; // 获得主线程的RunLoop对象

CFRunLoopGetCurrent(); // 获得当前线程的RunLoop对象
CFRunLoopGetMain(); // 获得主线程的RunLoop对象

RunLoop相关类

RunLoop.png

CFRunLoopModeRef

CFRunLoopSourceRef

CFRunLoopTimerRef

CFRunLoopObserverRef

/* Run Loop Observer Activities */
typedef CF_OPTIONS(CFOptionFlags, CFRunLoopActivity) {
    kCFRunLoopEntry = (1UL << 0),//即将进入Loop
    kCFRunLoopBeforeTimers = (1UL << 1),//即将处理Timer
    kCFRunLoopBeforeSources = (1UL << 2),//即将处理Source
    kCFRunLoopBeforeWaiting = (1UL << 5),//即将进入休眠
    kCFRunLoopAfterWaiting = (1UL << 6),//刚从休眠中唤醒
    kCFRunLoopExit = (1UL << 7),//即将推出Loop
    kCFRunLoopAllActivities = 0x0FFFFFFFU
};

RunLoop处理逻辑-官方版

RunLoop处理逻辑-网友整理版

RunLoop应用

-(void)timer
{
    NSTimer *timer = [NSTimer timerWithTimeInterval:2.0 target:self selector:@selector(run) userInfo:nil repeats:YES];
    // 定时器只运行在NSDefaultRunLoopMode下，一旦RunLoop进入其他模式，这个定时器就不会工作
    //    [[NSRunLoop currentRunLoop] addTimer:timer forMode:NSDefaultRunLoopMode];
    
    // 定时器只运行在UITrackingRunLoopMode下，一旦RunLoop进入其他模式，这个定时器就不会工作
    //    [[NSRunLoop currentRunLoop] addTimer:timer forMode:UITrackingRunLoopMode];
    
    // 定时器会跑在标记为common modes的模式下
    // 标记为common modes的模式：UITrackingRunLoopMode和NSDefaultRunLoopMode
    [[NSRunLoop currentRunLoop] addTimer:timer forMode:NSRunLoopCommonModes];
}

-(void)timer2
{
    // 调用了scheduledTimer返回的定时器，已经自动被添加到当前runLoop中，而且是NSDefaultRunLoopMode
    NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(run) userInfo:nil repeats:YES];
    
    // 修改模式
    [[NSRunLoop currentRunLoop] addTimer:timer forMode:NSRunLoopCommonModes];
}

-(void)viewDidLoad {
    [super viewDidLoad];
    
    self.thread = [[NSThread alloc] initWithTarget:self selector:@selector(execute) object:nil];
    [self.thread start];
}
-(void)execute
{
    [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(test) userInfo:nil repeats:YES];
    
    [[NSRunLoop currentRunLoop] run];
}

/*
    CF的内存管理（Core Foundation）
    1.凡是带有Create、Copy、Retain等字眼的函数，创建出来的对象，都需要在最后做一次release
    * 比如CFRunLoopObserverCreate
    2.release函数：CFRelease(对象);
 */
-(void)observer
{
    // 创建observer
    CFRunLoopObserverRef observer = CFRunLoopObserverCreateWithHandler(CFAllocatorGetDefault(), kCFRunLoopAllActivities, YES, 0, ^(CFRunLoopObserverRef observer, CFRunLoopActivity activity) {
        NSLog(@"----监听到RunLoop状态发生改变---%zd", activity);
    });

    // 添加观察者：监听RunLoop的状态
    CFRunLoopAddObserver(CFRunLoopGetCurrent(), observer, kCFRunLoopDefaultMode);
    
    // 释放Observer
    CFRelease(observer);
}

// 只在NSDefaultRunLoopMode模式下显示图片
    [self.imageView performSelector:@selector(setImage:) withObject:[UIImage imageNamed:@"placeholder"] afterDelay:3.0 inModes:@[NSDefaultRunLoopMode]];

//创建一个线程并开启
-(void)viewDidLoad {
    [super viewDidLoad]; 
    self.thread = [[NSThread alloc] initWithTarget:self selector:@selector(run) object:nil];
    [self.thread start];
}

//线程执行的方法
-(void)run
{
//打印当前线程
    NSLog(@"----------run----%@", [NSThread currentThread]);
//子线程需要手动创建runloop
    [[NSRunLoop currentRunLoop] addPort:[NSPort port] forMode:NSDefaultRunLoopMode];
    [[NSRunLoop currentRunLoop] run];
    NSLog(@"---------");
//    [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];
//    [[NSRunLoop currentRunLoop] runUntilDate:[NSDate distantFuture]];
}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    [self performSelector:@selector(test) onThread:self.thread withObject:nil waitUntilDone:NO];
}
-(void)test
{
    NSLog(@"----------test----%@", [NSThread currentThread]);
}
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