飞屏，用手机播放电脑端视频的功能，一般常见于主打VR资源的影音类App。
大体思路：基于UDP协议的广播机制
电脑端不断发送udp广播，广播内容可精简为：端口号；
App用udpSocket扫描，得到对应端口号信息，解析出IP地址，拼接数据，请求数据。
移动端的实现：
1.导入第三方库：CocoaAsyncSocket，引用文件
#import <GCDAsyncUdpSocket.h>
2.遵守协议：
<GCDAsyncUdpSocketDelegate>```
######3.初始化对象，启动监听：
_clientSocket = [[GCDAsyncUdpSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_main_queue()];
NSError * error = nil;
[_clientSocket setIPv6Enabled:NO]; //�每次扫描，你会收到两条信息，IPv4和IPv6的，根据需求做取舍。
[_clientSocket bindToPort:8080error:&error];// 8080,与电脑端统一的端口号
if (error) {
PVRLog(@"clientSocket_error:%@",error);
} else {
[_clientSocket beginReceiving:&error];
PVRLog(@"监听成功开始接收信息");
}
#####4.代理回调
pragma mark - GCDAsyncUdpSocket delegate
-
(void)udpSocket:(GCDAsyncUdpSocket *)sock didReceiveData:(NSData *)data fromAddress:(NSData *)address withFilterContext:(id)filterContext {
NSString *sendMessage = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
NSString *ip = [GCDAsyncUdpSocket hostFromAddress:address];
uint16_t port = [GCDAsyncUdpSocket portFromAddress:address];
PVRLog(@"接收到%@的消息,\n解析到的数据[%@:%d]",sendMessage,ip,port);
}
- (void)udpSocketDidClose:(GCDAsyncUdpSocket *)sock withError:(NSError *)error {
PVRLog(@"udpSocket关闭withError = %@", error);
}
####关于如何使用封装好的工具类，请参考代码
#####GitHub:https://github.com/YZQ-Nine/FlyScreenDemo