1.Ping域名亦歉、Ping某IP
有時(shí)候可能會(huì)遇到ping 某個(gè)域名或者ip通不通脯燃，再做下一步操作嵌牺。這里的ping與傳統(tǒng)的做get或者post請(qǐng)求還是有很大區(qū)別的帮辟。比如我們連接了某個(gè)WiFi速址，測(cè)試ping www.baidu.com，如果能ping 通由驹，基本可以斷定可以上網(wǎng)了芍锚，但是如果我們做了一個(gè)get 請(qǐng)求（url 是www.baidu.com）,路由器可能重定向這個(gè)WiFi內(nèi)的某網(wǎng)頁(yè)了，依然沒(méi)有錯(cuò)誤返回蔓榄，就會(huì)誤認(rèn)為可以正常上網(wǎng)并炮。
這里有關(guān)于ping命令的詳細(xì)解釋：百度百科Ping
iOS中想要ping域名或者ip，蘋果提供了一個(gè)官方例子SimplePing
在例子中甥郑，有一個(gè)蘋果已經(jīng)封裝過(guò)的類【SimplePing.h】和【SimplePing.m】
使用起來(lái)也相當(dāng)?shù)暮?jiǎn)單：
首先創(chuàng)建一個(gè)Ping對(duì)象：

SimplePing *pinger = [[SimplePing alloc] initWithHostName:self.hostName];
 self.pinger = pinger;
 pinger.delegate = self;
 pinger.addressStyle = SimplePingAddressStyleICMPv4;
 [pinger start];

然后在start成功的代理方法中逃魄，發(fā)送數(shù)據(jù)報(bào)文：

/**
 *  start成功，也就是準(zhǔn)備工作做完后的回調(diào)
 */
- (void)simplePing:(SimplePing *)pinger didStartWithAddress:(NSData *)address
{
    // 發(fā)送測(cè)試報(bào)文數(shù)據(jù)
    [self.pinger sendPingWithData:nil];
}
- (void)simplePing:(SimplePing *)pinger didFailWithError:(NSError *)error
{
    NSLog(@"didFailWithError");
    [self.pinger stop];
}

其他幾個(gè)代理方法也非常簡(jiǎn)單澜搅，就簡(jiǎn)單記錄一下：

// 發(fā)送測(cè)試報(bào)文成功的回調(diào)方法
- (void)simplePing:(SimplePing *)pinger didSendPacket:(NSData *)packet sequenceNumber:(uint16_t)sequenceNumber
{
    NSLog(@"#%u sent", sequenceNumber);
}
//發(fā)送測(cè)試報(bào)文失敗的回調(diào)方法
- (void)simplePing:(SimplePing *)pinger didFailToSendPacket:(NSData *)packet sequenceNumber:(uint16_t)sequenceNumber error:(NSError *)error
{
    NSLog(@"#%u send failed: %@", sequenceNumber, error);
}
// 接收到ping的地址所返回的數(shù)據(jù)報(bào)文回調(diào)方法
- (void)simplePing:(SimplePing *)pinger didReceivePingResponsePacket:(NSData *)packet sequenceNumber:(uint16_t)sequenceNumber
{
    NSLog(@"#%u received, size=%zu", sequenceNumber, packet.length);
}
- (void)simplePing:(SimplePing *)pinger didReceiveUnexpectedPacket:(NSData *)packet
{
    NSLog(@"#%s",__func__);
}

注意點(diǎn)：
iOS 中 ping失敗后（即發(fā)送測(cè)試報(bào)文成功后伍俘，一直沒(méi)后收到響應(yīng)的報(bào)文）,不會(huì)有任何回調(diào)方法告知我們。而一般ping 一次的結(jié)果也不太準(zhǔn)確勉躺，ping 花費(fèi)的時(shí)間也非常短癌瘾，所以我們一般會(huì)ping多次，發(fā)送一次ping 測(cè)試報(bào)文0.5s后檢測(cè)一下這一次ping是否已經(jīng)收到響應(yīng)饵溅。0.5s后檢測(cè)時(shí)妨退，如果已經(jīng)收到響應(yīng)，則可以ping 通蜕企；如果沒(méi)有收到響應(yīng)咬荷，則視為超時(shí)。
做法也有很多種糖赔，可以用NSTimer或者 {- (void)performSelector: withObject:afterDelay:}
這里有一個(gè)別人寫的工程：https://github.com/lovesunstar/STPingTest

2.獲取WiFi信息
以前物聯(lián)網(wǎng)剛火的時(shí)候萍丐，出現(xiàn)過(guò)很多一體式無(wú)線路由，所以App里難免會(huì)遇到要判斷當(dāng)前所連接的WiFi放典，以及獲取WiFi信息的功能逝变。
需要添加SystemConfiguration.framework 并在當(dāng)前類中添加代碼#import

//獲取WiFi 信息，返回的字典中包含了WiFi的名稱奋构、路由器的Mac地址壳影、還有一個(gè)Data(轉(zhuǎn)換成字符串打印出來(lái)是wifi名稱)
- (NSDictionary *)fetchSSIDInfo {
    NSArray *ifs = (__bridge_transfer NSArray *)CNCopySupportedInterfaces();
    if (!ifs) {
        return nil;
    }
    NSDictionary *info = nil;
    for (NSString *ifnam in ifs) {
        info = (__bridge_transfer NSDictionary *)CNCopyCurrentNetworkInfo((__bridge CFStringRef)ifnam);
        if (info && [info count]) { break; }
    }
    return info;
}
//打印出來(lái)的結(jié)果：
2016-05-12 15:28:51.674 SimplePing[18883:6790207] WIFI_INFO:{
    BSSID = "a4:2b:8c:c:7f:bd";
    SSID = bdmy06;
    SSIDDATA = ;
}

3.獲取WiFi名稱
有了上一步，獲取WiFi名稱就非常簡(jiǎn)單了弥臼。

NSString *WiFiName = info[@"SSID"];

完整的：

- (NSString *)fetchWiFiName {
    NSArray *ifs = (__bridge_transfer NSArray *)CNCopySupportedInterfaces();
    if (!ifs) {
        return nil;
    }
    NSString *WiFiName = nil;
    for (NSString *ifnam in ifs) {
        NSDictionary *info = (__bridge_transfer NSDictionary *)CNCopyCurrentNetworkInfo((__bridge CFStringRef)ifnam);
        if (info && [info count]) {
            // 這里其實(shí)對(duì)應(yīng)的有三個(gè)key:kCNNetworkInfoKeySSID宴咧、kCNNetworkInfoKeyBSSID、kCNNetworkInfoKeySSIDData径缅，
            // 不過(guò)它們都是CFStringRef類型的
            WiFiName = [info objectForKey:(__bridge NSString *)kCNNetworkInfoKeySSID];
//            WiFiName = [info objectForKey:@"SSID"];
            break;
        }
    }
    return WiFiName;
}

4.獲取當(dāng)前所連接WiFi的網(wǎng)關(guān)地址
例如自己家的路由器一般默認(rèn)的網(wǎng)關(guān)地址是192.168.1.1掺栅，獲取的就是這個(gè)192.168.1.1烙肺。
因?yàn)橐恍┥虉?chǎng)或者有多個(gè)路由器的網(wǎng)關(guān)地址是不一樣的，比如之前有個(gè)公司的網(wǎng)關(guān)是192.168.89.1氧卧。
需要導(dǎo)入的庫(kù)：

#import #import #import    //此處由于時(shí)間原因有所遺忘桃笙，后期會(huì)給予更改

獲取網(wǎng)關(guān)的方法

- (NSString *)getGatewayIpForCurrentWiFi {
    NSString *address = @"error";
    struct ifaddrs *interfaces = NULL;
    struct ifaddrs *temp_addr = NULL;
    int success = 0;
    // retrieve the current interfaces - returns 0 on success
    success = getifaddrs(&interfaces);
    if (success == 0) {
        // Loop through linked list of interfaces
        temp_addr = interfaces;
        //*/
        while(temp_addr != NULL) {
        /*/
         int i=255;
         while((i--)>0)
         //*/
            if(temp_addr->ifa_addr->sa_family == AF_INET) {
                // Check if interface is en0 which is the wifi connection on the iPhone
                if([[NSString stringWithUTF8String:temp_addr->ifa_name] isEqualToString:@"en0"])
                {
                    // Get NSString from C String //ifa_addr
                    //ifa->ifa_dstaddr is the broadcast address, which explains the "255's"
                    //                    address = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_dstaddr)->sin_addr)];
                    address = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)];
                    //routerIP----192.168.1.255 廣播地址
                    NSLog(@"broadcast address--%@",[NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_dstaddr)->sin_addr)]);
                    //--192.168.1.106 本機(jī)地址
                    NSLog(@"local device ip--%@",[NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)]);
                    //--255.255.255.0 子網(wǎng)掩碼地址
                    NSLog(@"netmask--%@",[NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_netmask)->sin_addr)]);
                    //--en0 端口地址
                    NSLog(@"interface--%@",[NSString stringWithUTF8String:temp_addr->ifa_name]);
                }
            }
            temp_addr = temp_addr->ifa_next;
        }
    }
    // Free memory
    freeifaddrs(interfaces);
    in_addr_t i = inet_addr([address cStringUsingEncoding:NSUTF8StringEncoding]);
    in_addr_t* x = &i;
    unsigned char *s = getdefaultgateway(x);
    NSString *ip=[NSString stringWithFormat:@"%d.%d.%d.%d",s[0],s[1],s[2],s[3]];
    free(s);
    return ip;
}

其中 getdefaultgateway 是一個(gè)C語(yǔ)言文件中的方法，在工程里可以找到沙绝。
5.獲取本機(jī)在WiFi環(huán)境下的IP地址
獲取本機(jī)在WiFi環(huán)境下的ip地址搏明，在上一節(jié)中其實(shí)已經(jīng)寫過(guò)，這里將其提取出來(lái)即可：

- (NSString *)getLocalIPAddressForCurrentWiFi
{
    NSString *address = nil;
    struct ifaddrs *interfaces = NULL;
    struct ifaddrs *temp_addr = NULL;
    int success = 0;
    // retrieve the current interfaces - returns 0 on success
    success = getifaddrs(&interfaces);
    if (success == 0) {
        // Loop through linked list of interfaces
        temp_addr = interfaces;
        while(temp_addr != NULL) {
            if(temp_addr->ifa_addr->sa_family == AF_INET) {
                // Check if interface is en0 which is the wifi connection on the iPhone
                if([[NSString stringWithUTF8String:temp_addr->ifa_name] isEqualToString:@"en0"]) {
                    address = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)];
                    return address;
                }
            }
            temp_addr = temp_addr->ifa_next;
        }
        freeifaddrs(interfaces);
    }
    return nil;
}

同樣的方式也可以獲取廣播地址闪檬、子網(wǎng)掩碼星著、端口等，組裝成一個(gè)字典粗悯。

- (NSMutableDictionary *)getLocalInfoForCurrentWiFi {
    NSMutableDictionary *dict = [NSMutableDictionary dictionary];
    struct ifaddrs *interfaces = NULL;
    struct ifaddrs *temp_addr = NULL;
    int success = 0;
    // retrieve the current interfaces - returns 0 on success
    success = getifaddrs(&interfaces);
    if (success == 0) {
        // Loop through linked list of interfaces
        temp_addr = interfaces;
        //*/
        while(temp_addr != NULL) {
            if(temp_addr->ifa_addr->sa_family == AF_INET) {
                // Check if interface is en0 which is the wifi connection on the iPhone
                if([[NSString stringWithUTF8String:temp_addr->ifa_name] isEqualToString:@"en0"]) {
                    //----192.168.1.255 廣播地址
                    NSString *broadcast = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_dstaddr)->sin_addr)];
                    if (broadcast) {
                        [dict setObject:broadcast forKey:@"broadcast"];
                    }
                    NSLog(@"broadcast address--%@",broadcast);
                    //--192.168.1.106 本機(jī)地址
                    NSString *localIp = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)];
                    if (localIp) {
                        [dict setObject:localIp forKey:@"localIp"];
                    }
                    NSLog(@"local device ip--%@",localIp);
                    //--255.255.255.0 子網(wǎng)掩碼地址
                    NSString *netmask = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_netmask)->sin_addr)];
                    if (netmask) {
                        [dict setObject:netmask forKey:@"netmask"];
                    }
                    NSLog(@"netmask--%@",netmask);
                    //--en0 端口地址
                    NSString *interface = [NSString stringWithUTF8String:temp_addr->ifa_name];
                    if (interface) {
                        [dict setObject:interface forKey:@"interface"];
                    }
                    NSLog(@"interface--%@",interface);
                    return dict;
                }
            }
            temp_addr = temp_addr->ifa_next;
        }
    }
    // Free memory
    freeifaddrs(interfaces);
    return dict;
}