为什么我的后台线程不运行？

Question

doBackgroundWork方法不会从startDoingWork方法中调用。

threading.h 
    ------------ 
    #import <Foundation/Foundation.h> 

    @interface threading : NSObject { 

     NSConditionLock* theConditionLock; 
     NSMutableArray* workItems; 

    } 
    -(void)startDoingWork; 
    -(void)doBackgroundWork; 
    -(void)notifyBackgroundThreadAboutNewWork; 
    @end 


    threading.m 
    ------------- 

    #import "threading.h" 

    enum{ 
     workToDoNow = 1, 
     workNotToDoNow = 0 
    }; 

    @implementation threading 

    -(id)init{ 
     if (self = [super init]) { 
      theConditionLock = [[NSConditionLock alloc]initWithCondition:workNotToDoNow]; 
      workItems = [[NSMutableArray alloc]init]; 
     } 
     return self; 
    } 
    -(void)startDoingWork{ 
     [NSThread detachNewThreadSelector:@selector(doBackgroundWork) toTarget:self withObject:nil]; 
    } 
    -(void)doBackgroundWork{ 
     while (YES) { 
      NSAutoreleasePool* pool = [[NSAutoreleasePool alloc]init]; 
      NSArray* items = nil; 
      NSLog(@"Going to lock!!"); 
      [theConditionLock lockWhenCondition:workToDoNow]; 
      items = [NSArray arrayWithArray:workItems]; 
      [workItems removeAllObjects]; 
      [theConditionLock unlockWithCondition:workNotToDoNow]; 
      NSLog(@"Finished the work!!"); 
      [pool drain]; 
     } 
    } 
    -(void)notifyBackgroundThreadAboutNewWork{ 
     NSLog(@"Into the Background new work!!"); 
     [theConditionLock lock]; 
     [workItems addObject:@"Hello"]; 
     [theConditionLock unlockWithCondition:workToDoNow]; 
     NSLog(@"Finished and came out!!"); 
    } 
    @end 

    main.m 
    ------ 
    #import <Foundation/Foundation.h> 
    #import "threading.h" 

    int main (int argc, const char * argv[]) { 
     NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; 
     threading* threads = [[threading alloc]init]; 
     [threads notifyBackgroundThreadAboutNewWork]; 
     [threads startDoingWork]; 
     [pool drain]; 
     return 0; 
    } 

detachNewThread：selector：toTarget：withObject方法在调试时不会被调用。

Answer 1

是不是你的主要目的快，后台线程没有机会开始？你知道，即使在运行时间管理设置和启动新线程之前，应用程序已经完成，所有的线程被杀死/关闭/不管。您可以让主线程休眠一秒，以查看后台线程是否开始运行。

Answer 2

我相信你的工作线程选择器应该只有一个参数。