子线程里调用performSelector须要注意什么

时间 2019-12-13

标签线程调用 performselector 须要注意什么繁體版

原文原文链接

如下代码执行顺序是什么 ?async

- (void)action {oop

NSLog(@"1");spa

dispatch_queue_t queue = dispatch_get_global_queue(0, 0);线程

dispatch_async(queue, ^{orm

NSLog(@"3");get

[self performSelector:@selector(test) withObject:nil afterDelay:0.0f];it

NSLog(@"4");io

});table

NSLog(@"2");form

}

- (void)test {

NSLog(@"5");

}

结果

2019-07-02 09:24:18.492671+0800 ModelTest[12945:510979] 1

2019-07-02 09:24:18.492776+0800 ModelTest[12945:510979] 2

2019-07-02 09:24:18.492807+0800 ModelTest[12945:511386] 3

2019-07-02 09:24:18.493009+0800 ModelTest[12945:511386] 4

test方法没有调用。由于子线程里runloop默认是关闭的。改成一下代码后

- (void)action {

NSLog(@"1");

dispatch_queue_t queue = dispatch_get_global_queue(0, 0);

dispatch_async(queue, ^{

NSLog(@"3");

[self performSelector:@selector(test) withObject:nil afterDelay:0.0f];

[[NSRunLoop currentRunLoop]run];

NSLog(@"4");

});

NSLog(@"2");

}

- (void)test {

NSLog(@"5");

}

结果

2019-07-02 09:38:40.874213+0800 ModelTest[13094:524707] 1

2019-07-02 09:38:40.874530+0800 ModelTest[13094:524707] 2

2019-07-02 09:38:40.874551+0800 ModelTest[13094:524802] 3

2019-07-02 09:38:43.792863+0800 ModelTest[13094:524802] 5

2019-07-02 09:38:43.793109+0800 ModelTest[13094:524802] 4