相关疑难解决方法(0)

我正试图在iPhone的后台运行一个长时间的任务.我开始吧performSelectorInBackground.我还在NSTimer主线程上创建一个只是为了检查是否有效.我期望计时器会在另一个线程运行时运行:

- (void)viewDidLoad
{
    [super viewDidLoad];

    [NSTimer scheduledTimerWithTimeInterval:0.1 target:self
                   selector:@selector(onTimerEvent:)
                   userInfo:nil repeats:YES];   

   [self performSelectorInBackground:@selector(lengthyMethod) withObject:nil];

    NSLog(@"Here we go!");
}

- (void)onTimerEvent:(NSTimer *)timer
{
    NSLog(@"timer!");
}

该lenghtyMethod执行的东西很多,包括使用URL下载ASIHTTPRequest等.

输出NSLog如下所示:

2011-03-11 15:17:07.470 MyApp[6613:207] Here we go!    
2011-03-11 15:17:07.570 MyApp[6613:207] timer!
2011-03-11 15:17:07.670 MyApp[6613:207] timer!

// ... several seconds of output from lenghtyMethod omitted ...

2011-03-11 15:17:11.075 MyApp[6613:207] timer!
2011-03-11 15:17:11.170 MyApp[6613:207] timer!
// ... etc ... timer runs as expected when the call …