身處物聯(lián)網(wǎng)崛浪潮中，不懂socket似乎有點(diǎn)說不過去。WiFi設(shè)備建立連接的時(shí)候，基本都是用UDP廣播。本文就來聊聊怎么UDP廣播玩~
其實(shí)socket已經(jīng)非常成熟，github上有不少優(yōu)秀的第三方，其中比較常用的就是 CocoaAsyncSocket 。CocoaAsyncSocket中包含了GCDAsyncSocket和GCDAsyncUdpSocket，本文主要講udp所以只需要把其中的GCDAsyncUdpSocket.h和GCDAsyncUdpSocket.m兩個(gè)文件拖進(jìn)自己工程就可以了~
接下來就來看看寫個(gè)UDP廣播demo到底有多簡(jiǎn)單。我們新建一個(gè)類UDPManage來進(jìn)行管理。首先，當(dāng)然是導(dǎo)入GCDAsyncUdpSocket.h，并遵守GCDAsyncUdpSocketDelegate，然后創(chuàng)建一個(gè)UDPManage的單例來進(jìn)行操作。代碼如下：
#import "UDPManage.h"
#import "GCDAsyncUdpSocket.h"
#define udpPort 9527
@interface UDPManage () <GCDAsyncUdpSocketDelegate>
@property (strong, nonatomic)GCDAsyncUdpSocket * udpSocket;
@end
static UDPManage *myUDPManage = nil;
@implementation UDPManage
+(instancetype)shareUDPManage{
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
myUDPManage = [[UDPManage alloc]init];
[myUDPManage createClientUdpSocket];
});
return myUDPManage;
}
-(void)createClientUdpSocket{
//創(chuàng)建udp socket
self.udpSocket = [[GCDAsyncUdpSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)];
//banding一個(gè)端口(可選),如果不綁定端口,那么就會(huì)隨機(jī)產(chǎn)生一個(gè)隨機(jī)的電腦唯一的端口
NSError * error = nil;
[self.udpSocket bindToPort:udpPort error:&error];
//啟用廣播
[self.udpSocket enableBroadcast:YES error:&error];
if (error) {//監(jiān)聽錯(cuò)誤打印錯(cuò)誤信息
NSLog(@"error:%@",error);
}else {//監(jiān)聽成功則開始接收信息
[self.udpSocket beginReceiving:&error];
}
}
//廣播
-(void)broadcast{
NSString *str = @"大圣遛碼";
NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding];
//此處如果寫成固定的IP就是對(duì)特定的server監(jiān)測(cè)
NSString *host = @"255.255.255.255";
//發(fā)送數(shù)據(jù)（tag: 消息標(biāo)記）
[self.udpSocket sendData:data toHost:host port:udpPort withTimeout:-1 tag:100];
}
這樣就把消息廣播出去了，簡(jiǎn)單吧~還有更簡(jiǎn)單的——因?yàn)槲覀兪窍?code>255.255.255.255發(fā)送廣播，消息會(huì)發(fā)送到同一局域網(wǎng)內(nèi)的每一臺(tái)主機(jī)，也就是說自己也會(huì)收到，所以我們不需要再寫一個(gè)客戶端程序來接收，直接繼續(xù)往下寫,把代理方法實(shí)現(xiàn)就可以了：
#pragma mark GCDAsyncUdpSocketDelegate
//發(fā)送數(shù)據(jù)成功
-(void)udpSocket:(GCDAsyncUdpSocket *)sock didSendDataWithTag:(long)tag{
if (tag == 100) {
NSLog(@"標(biāo)記為100的數(shù)據(jù)發(fā)送完成了");
}
}
//發(fā)送數(shù)據(jù)失敗
-(void)udpSocket:(GCDAsyncUdpSocket *)sock didNotSendDataWithTag:(long)tag dueToError:(NSError *)error{
NSLog(@"標(biāo)記為%ld的數(shù)據(jù)發(fā)送失敗，失敗原因：%@",tag, error);
}
//接收到數(shù)據(jù)
-(void)udpSocket:(GCDAsyncUdpSocket *)sock didReceiveData:(NSData *)data fromAddress:(NSData *)address withFilterContext:(id)filterContext{
NSString *ip = [GCDAsyncUdpSocket hostFromAddress:address];
uint16_t port = [GCDAsyncUdpSocket portFromAddress:address];
NSString *str = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"收到服務(wù)端的響應(yīng) [%@:%d] %@", ip, port, str);
}
簡(jiǎn)單吧，接下來只需要在ViewController里面調(diào)用一下[[UDPManage shareUDPManage] broadcast];，就可以看到下圖結(jié)果了：
