RunLoop如何开一条常驻线程(面试题)

• 在开发中如何使用RunLoop?什么应用场景

  • 在子线程中进行一些长期监控

  • 在子线程中开启一个定时器

#import "ViewController.h"

@interface ViewController ()
@property (nonatomic, strong) NSThread *thread;
@end

@implementation ViewController
- (IBAction)creatThread:(id)sender
{
    self.thread = [[NSThread alloc]initWithTarget:self selector:@selector(task1) object:nil];
    [self.thread start];
}
- (IBAction)continueThread:(id)sender
{
    [self performSelector:@selector(task2) onThread:self.thread withObject:nil waitUntilDone:YES];
}
-(void)task1
{
    NSLog(@"task1----%@",[NSThread currentThread]);
    //1.创建RunLoop
    NSRunLoop *loop = [NSRunLoop currentRunLoop];
    //2.保证RunLoop不退出
    [loop addPort:[NSPort port] forMode:NSDefaultRunLoopMode];
//    [loop runUntilDate:[NSDate dateWithTimeIntervalSinceNow:10]]; 10秒钟之后runloop退出,该方法在主线程中设置无效。
    //3.开启RunLoop，默认不开启
    [loop run];
    
    NSLog(@"----end------");
}
-(void)task2
{
    NSLog(@"task2----%@",[NSThread currentThread]);
}
@end