ios多线程的几种创建方式

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];         //创建线程的第一种方式    NSThread *thread = [[NSThread alloc] initWithTarget:self selector:@selector(run:) object:@"universe"];    [thread start];    [thread release];              //创建线程的第二种方式，NSThread类方法    [NSThread detachNewThreadSelector:@selector(run:) toTarget:self withObject:@"yuzhou"];              //创建线程的第三种方法  NSObject方法    [self performSelectorInBackground:@selector(run:) withObject:@"nsobject thread"];         //创建线程的第四种方式    NSOperationQueue *oprationQueue = [[NSOperationQueue alloc] init];    [oprationQueue addOperationWithBlock:^{        //这个block语句块在子线程中执行        NSLog(@"oprationQueue");    }];    [oprationQueue release];         //第五种创建线程的方式    NSOperationQueue *oprationQueue1 = [[NSOperationQueue alloc] init];    oprationQueue1.maxConcurrentOperationCount = 1;//指定池子的并发数         //NSOperation 相当于java中的runnable接口，继承自它的就相当一个任务    NSInvocationOperation *invation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(run:) object:@"invation"];    [oprationQueue1 addOperation:invation];//将任务添加到池子里面，可以给池子添加多个任务，并且指定它的并发数    [invation release];         //第二个任务    NSInvocationOperation *invation2 = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(run2:) object:@"invocation2"];    invation2.queuePriority = NSOperationQueuePriorityHigh;//设置线程优先级    [oprationQueue1 addOperation:invation2];    [invation2 release];         [oprationQueue1 release];         //调用主线程，用来子线程和主线程交互,最后面的那个boolean参数，如果为yes就是等这个方法执行完了在执行后面的代码；如果为no的话，就是不管这个方法执行完了没有，接着往下走    [self performSelectorOnMainThread:@selector(onMain) withObject:self waitUntilDone:YES];         //---------------------GCD----------------------支持多核，高效率的多线程技术    //创建多线程第六种方式    dispatch_queue_t queue = dispatch_queue_create("name", NULL);    //创建一个子线程    dispatch_async(queue, ^{        // 子线程code... ..        NSLog(@"GCD多线程");                 //回到主线程        dispatch_sync(dispatch_get_main_queue(), ^{//其实这个也是在子线程中执行的，只是把它放到了主线程的队列中            Boolean isMain = [NSThread isMainThread];            if (isMain) {                NSLog(@"GCD主线程");            }        });    });              self.window.backgroundColor = [UIColor whiteColor];    [self.window makeKeyAndVisible];    return YES;} - (void)onMain{    Boolean b = [NSThread isMainThread];    if (b) {        NSLog(@"onMain;;%d",b);    }}  - (void) run:(NSString*)str{    NSLog(@"多线程运行:::%@",str);}- (void) run2:(NSString*)str{    NSLog(@"多线程运行:::%@",str);}