RunLoop开辟常驻线程

runLoop创建一个常驻线程,多次用到子线程去处理事件,避免频繁的创建,销毁线程,每条线程都有一个RunLoop,他只有能获取到RunLoop.主线程也是通过创建(main函数中)才有的RunLoop

- (void)viewDidLoad {

[super viewDidLoad];

[self threadTest];

}

- (void)threadTest{

NSThread *subThread = [[NSThread alloc] initWithTarget:self selector:@selector(subThreadEntryPoint) object:nil];

[subThread setName:@"TestThread"];

[subThread start];

self.subThread = subThread;

}

//子线程启动后，启动runloop

- (void)subThreadEntryPoint{

@autoreleasepool {

NSRunLoop *runLoop = [NSRunLoop currentRunLoop];

//如果注释了下面这一行，子线程中的任务并不能正常执行

//1.开启RunLoop死循环

[runLoop addPort:[NSMachPort port] forMode:NSRunLoopCommonModes];

//2.当前RunLoop,并不是创建新的RunLoop,RunLoop是懒加载的过程,只有第一次是创建,虽然是死循环,但是可以执行该线程外(在此子线程上)的消息

[[NSRunLoop currentRunLoop] run];

//3.通过控制_finished值来中指RunLoop,或者更粗暴的终止线程[NSThread exit];

while(!_finished) {

[[NSRunLoop currentRunLoop]runUntilDate:[NSDatedateWithTimeIntervalSinceNow:0.0001]];

}

NSLog(@"启动RunLoop前--%@",runLoop.currentMode);

[runLoop run];

}

//子线程任务

- (void)subThreadOpetion{

NSLog(@"启动RunLoop后--%@",[NSRunLoop currentRunLoop].currentMode);

NSLog(@"%@----子线程任务开始",[NSThread currentThread]);

[NSThread sleepForTimeInterval:3.0];//模拟事件}

NSLog(@"%@----子线程任务结束",[NSThread currentThread]);

}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{

[self performSelector:@selector(subThreadOpetion) onThread:self.subThread

withObject:nil waitUntilDone:NO];

}

}