iOS下的WiFi开发

　　iOS下Wi-Fi开发需要添加依赖库SystemConfiguration.framework，在需要使用Wi-Fi信息的控制器下引入头文件#import <SystemConfiguration/CaptiveNetwork.h>

　　1，Wi-Fi热点获取

+(NSString *) currentWifiSSID
{
#if TARGET_OS_SIMULATOR
    return @"(simulator)";
#else
    NSArray *ifs = (__bridge id)CNCopySupportedInterfaces();

    id info = nil;
    for (NSString *ifnam in ifs) {
        info = (__bridge id)CNCopyCurrentNetworkInfo((__bridge CFStringRef)ifnam);
        if (info && [info count]) {
            break;
        }
    }
    NSDictionary *dctySSID = (NSDictionary *)info;
    NSString *ssid = [dctySSID objectForKey:@"SSID"] ;

    return ssid;
#endif
}

　　2，取得本机Wi-Fi的IP地址

#include <arpa/inet.h>
#include <netdb.h>
#include <net/if.h>
#include <ifaddrs.h>
#import <dlfcn.h>

+(NSString *) localWiFiIPAddress
{
    BOOL success;
    struct ifaddrs * addrs;
    const struct ifaddrs * cursor;

    success = getifaddrs(&addrs) == ;
    if (success) {
        cursor = addrs;
        while (cursor != NULL) {
            // the second test keeps from picking up the loopback address
            if (cursor->ifa_addr->sa_family == AF_INET && (cursor->ifa_flags & IFF_LOOPBACK) == )
            {
                NSString *name = [NSString stringWithUTF8String:cursor->ifa_name];
                if ([name isEqualToString:@"en0"])  // Wi-Fi adapter
                    return [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)cursor->ifa_addr)->sin_addr)];
            }
            cursor = cursor->ifa_next;
        }
        freeifaddrs(addrs);
    }
    return nil;
}

　　3，获取当前Wi-Fi的名称

- (void)GetWifiName{

NSString *wifiName = @"Not Found";

CFArrayRef myArray = CNCopySupportedInterfaces();

if (myArray != nil) {

CFDictionaryRef myDict =CNCopyCurrentNetworkInfo(CFArrayGetValueAtIndex(myArray, ));

if (myDict != nil) {

NSDictionary *dict = (NSDictionary*)CFBridgingRelease(myDict);

wifiName = [dict valueForKey:@"SSID"];

}

NSLog(@"wifiName:%@", wifiName);

}

　　注意：需要真机才能测试！模拟器下返回空。

　　4，打开系统设置

　　从应用跳到系统设置里的WiFi界面有这个需求存在吗？答案是肯定的。

　　在没有网的状态下，你可能想提醒用户去设置界面连接WiFi。如果不能跳到WiFi界面，只能在APP里面做出文字提示。这样很多小白用户可能不会看提示，只会觉得APP没有做好。

+(void)openSystemSetting:(NSString *)settingName{
    //iOS8 才有效
    float version = [[[UIDevice currentDevice] systemVersion] floatValue];

#if __IPHONE_OS_VERSION_MAX_ALLOWED < __IPHONE_8_0
#define SETTING_URL @"app-settings:"
#else
#define SETTING_URL   UIApplicationOpenSettingsURLString
#endif

    //  NSLog(UIApplicationOpenSettingsURLString);
    if (version >= 8.0){
        [[UIApplication sharedApplication] openURL:
         [NSURL URLWithString:SETTING_URL]];
    }
}

UIApplication.sharedApplication().openURL(NSURL(string: "prefs:root=WIFI")!)