iOS GCDAsyncUdpSocket UDP 建立连接,实现组播

iOS GCDAsyncUdpSocket UDP 建立连接,实现组播

导入框架 #import “GCDAsyncUdpSocket.h”,
接收代理 @interface RootViewController : UIViewController< GCDAsyncUdpSocketDelegate>

- (void)viewDidLoad {
    [super viewDidLoad];
    [self initSendUDPSocket];
    [self initReceiveUDPSocket];
    }

// 初始化发送 UDP socket 
-(void)initSendUDPSocket{
    self.sendUDPSocket = [[GCDAsyncUdpSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)];
    NSErro