iOS之創建一個常駐線程

// 當創建一個線程，並且希望它一直存在時，但往往我們創建的線程都是執行完成之后也就停止了，不能再次利用，那么如何創建一個線程可以讓他可以再次工作呢,這個時候就需要使用到RunLoop了。下面的是我寫的一個例子：
#import "LongThreadDemoController.h"

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

@end

@implementation LongThreadDemoController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
    self.title = @"常駐線程Demo";
    
}

- (void)threadRunloopPoint:(id)__unused object{
    NSLog(@"%@",NSStringFromSelector(_cmd));
    @autoreleasepool {
        [[NSThread currentThread] setName:@"changzhuThread"];
        NSRunLoop *runLoop = [NSRunLoop currentRunLoop];
        //// 這里主要是監聽某個 port，目的是讓這個 Thread 不會回收
        [runLoop addPort:[NSMachPort port] forMode:NSDefaultRunLoopMode];
        [runLoop run];
    }
}


- (NSThread *)thread{
    
    if(!_thread){
        _thread = [[NSThread alloc] initWithTarget:self selector:@selector(threadRunloopPoint:) object:nil];
        [_thread start];
    }
    return _thread;
    
}



- (void)test{
    
    NSLog(@"%s",__func__);
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
    
    
    [self performSelector:@selector(test) onThread:self.thread withObject:nil waitUntilDone:NO modes:@[NSDefaultRunLoopMode]];
    
}