为什么我的后台线程不运行？

如何解决为什么我的后台线程不运行？

| 不会从startDoingWork方法中调用doBackgroundWork方法。

 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;
    }

调试时不会调用detachNewThread：selector：toTarget：withObject方法。     

解决方法

        是不是您的主程序结束得如此之快，以至于后台线程没有启动的机会？您知道，即使在运行时设法建立和启动新线程之前，应用程序也已完成，并且所有线程都被杀死/关闭/无论如何。您可以使主线程休眠一秒钟，以查看后台线程是否开始运行。     ,        我相信您的工作线程选择器应该只接受一个参数。