小编uba*_*aci的帖子

我在UIScrollView中放置了一个UIImageView,基本上这个UIImageView拥有非常大的地图,并在预定义的路径上用"箭头"指向导航方向创建动画.

但是,每当发生uiscrollevents时,我认为MainLoop冻结并且NSTimer没有被触发,并且动画停止了.

在UIScrollView,CAKeyFrameAnimation或NSTimer上是否存在解决此问题的现有属性？

//viewDidLoad
   self.myTimer = [NSTimer scheduledTimerWithTimeInterval:0.05 target:self selector:@selector(drawLines:) userInfo:nil repeats:YES];

- (void)drawLines:(NSTimer *)timer {

   CALayer *arrow = [CALayer layer];
   arrow.bounds = CGRectMake(0, 0, 5, 5);
   arrow.position = CGPointMake(line.x1, line.y1);
   arrow.contents = (id)([UIImage imageNamed:@"arrow.png"].CGImage);

   [self.contentView.layer addSublayer:arrow];

   CAKeyframeAnimation* animation = [CAKeyframeAnimation animation];
   animation.path = path;
   animation.duration = 1.0;
   animation.rotationMode = kCAAnimationRotateAuto; // object auto rotates to follow the path
   animation.repeatCount = 1;
   animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
   animation.fillMode = kCAFillModeForwards;

   [arrow addAnimation:animation forKey:@"position"];
}

关于boost-asio多线程程序,我无法成功.

由于没有任何关于此的好例子或文档,我希望得到你的帮助:)

简单地说,我认为这段代码可以监听,但是当我想要"缓存"缓冲数据时,它不会打印任何内容或者只听一次并停止.

我的代码是:

void Worker::startThread(int clientNumber) {
     cout << "listening: "<< clients[clientNumber]->port << endl;
     boost::asio::io_service io_service;
     tcp::acceptor acc(io_service, tcp::endpoint(tcp::v4(),portNumber[clientNumber]));
     socket_ptr sock(new tcp::socket(io_service));
     acc.accept(*sock);
     try
     {
     for (;;) {
        char data[max_length];
        boost::system::error_code error;
         cout << "message?" << endl;
        size_t length = sock->read_some(boost::asio::buffer(data), error);
         cout << "message :)" << endl;
        cout << data << endl;
        if(error == boost::asio::error::eof)
            break; // Connection closed cleanly by peer.
        else if (error)
            throw boost::system::system_error(error); // Some other error.

     }
     }
     catch (std::exception& e)
     {
         std::cerr …