iOS实现WIFI传书

• 问题

  业务场景上存在需要将手机里的文件、图片传递给其他的设备，

  不仅仅局限于传书、资料啥的都有可能传递

• 方案

  最base的方法：设备之间加个云，设备上传资料到云，云同步资料到各个设备，适用于多设备之间，这个没讲的必要

  如果是两设备之间，忽略服务器，怎么搞？联想到图书App中的WiFi传书，貌似没云端概念的，怎么做到的？

• 上菜

  • 采用框架GCDWebServer，通过CocoaPods引入

  pod "GCDWebServer", "~> 3.0"
  

  • 设置本地接收目录，初始化Server并启动

  override func viewWillAppear(_ animated: Bool) {
      super.viewWillAppear(animated)
      
      if let filepath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first as NSString? {
          let path = filepath.appendingPathComponent("transfer")
          if !FileManager.default.fileExists(atPath: path) {
              do {
                  try FileManager.default.createDirectory(atPath: path, withIntermediateDirectories: false, attributes: nil)
              } catch {
                  print(error)
              }
          }
          
          webServer = GCDWebUploader(uploadDirectory: path)
          webServer?.delegate = self
          webServer?.allowHiddenItems = true
          webServer?.allowedFileExtensions = ["doc", "docx", "xls", "xlsx", "txt", "pdf", "jpeg", "jpg"]
          webServer?.title = "善斋工具"
          webServer?.prologue = "欢饮使用善斋工具的WIFI管理平台"
          webServer?.epilogue = "善斋书屋制作"
          
          if webServer?.start() == true, let address = IPHelper.deviceIPAdress(), address.count > 0, let port = webServer?.port {
              ipLb.text = "1.确保设备在同一局域网 \n2.上传时勿关闭该页面 \n3.请网页中输入该地址 \nhttp://\(address):\(port)/"
          } else {
              ipLb.text = "GCDWebServer not running!"
          }
      }
  }
  

  • 局域网内获取本机的ip地址，并设置其他设备访问链接

  #import 
  #import 
  #import 
  
  @implementation IPHelper
  
  + (NSString *)deviceIPAdress {
      NSString *address = @"";
      struct ifaddrs *interfaces = NULL;
      struct ifaddrs *temp_addr = NULL;
      int success = 0;
      success = getifaddrs(&interfaces);
      if (success == 0) { // 0 表示获取成功
          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"]) {
                      // Get NSString from C String
                      address = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)];
                  }
              }
              temp_addr = temp_addr->ifa_next;
          }
      }
      freeifaddrs(interfaces);
      return address;
      
  }
  
  
  #define IOS_CELLULAR    @"pdp_ip0"
  #define IOS_WIFI        @"en0"
  #define IOS_VPN         @"utun0"
  #define IP_ADDR_IPv4    @"ipv4"
  #define IP_ADDR_IPv6    @"ipv6"
  
  #pragma mark - 获取设备当前网络IP地址
  + (NSString *)getIPAddress:(BOOL)preferIPv4 {
      NSArray *searchArray = preferIPv4 ?
      @[ IOS_VPN @"/" IP_ADDR_IPv4, IOS_VPN @"/" IP_ADDR_IPv6, IOS_WIFI @"/" IP_ADDR_IPv4, IOS_WIFI @"/" IP_ADDR_IPv6, IOS_CELLULAR @"/" IP_ADDR_IPv4, IOS_CELLULAR @"/" IP_ADDR_IPv6 ] :
      @[ IOS_VPN @"/" IP_ADDR_IPv6, IOS_VPN @"/" IP_ADDR_IPv4, IOS_WIFI @"/" IP_ADDR_IPv6, IOS_WIFI @"/" IP_ADDR_IPv4, IOS_CELLULAR @"/" IP_ADDR_IPv6, IOS_CELLULAR @"/" IP_ADDR_IPv4 ] ;
      
      NSDictionary *addresses = [self getIPAddresses];
      NSLog(@"addresses: %@", addresses);
      
      __block NSString *address;
      [searchArray enumerateObjectsUsingBlock:^(NSString *key, NSUInteger idx, BOOL *stop)
       {
           address = addresses[key];
           //筛选出IP地址格式
           if([self isValidatIP:address]) *stop = YES;
       } ];
      return address ? address : @"0.0.0.0";
  }
  
  + (BOOL)isValidatIP:(NSString *)ipAddress {
      if (ipAddress.length == 0) {
          return NO;
      }
      NSString *urlRegEx = @"^([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\."
      "([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\."
      "([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\."
      "([01]?\\d\\d?|2[0-4]\\d|25[0-5])$";
      
      NSError *error;
      NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:urlRegEx options:0 error:&error];
      
      if (regex != nil) {
          NSTextCheckingResult *firstMatch=[regex firstMatchInString:ipAddress options:0 range:NSMakeRange(0, [ipAddress length])];
          
          if (firstMatch) {
              NSRange resultRange = [firstMatch rangeAtIndex:0];
              NSString *result=[ipAddress substringWithRange:resultRange];
              //输出结果
              NSLog(@"%@",result);
              return YES;
          }
      }
      return NO;
  }
  
  + (NSDictionary *)getIPAddresses
  {
      NSMutableDictionary *addresses = [NSMutableDictionary dictionaryWithCapacity:8];
      
      // retrieve the current interfaces - returns 0 on success
      struct ifaddrs *interfaces;
      if(!getifaddrs(&interfaces)) {
          // Loop through linked list of interfaces
          struct ifaddrs *interface;
          for(interface=interfaces; interface; interface=interface->ifa_next) {
              if(!(interface->ifa_flags & IFF_UP) /* || (interface->ifa_flags & IFF_LOOPBACK) */ ) {
                  continue; // deeply nested code harder to read
              }
              const struct sockaddr_in *addr = (const struct sockaddr_in*)interface->ifa_addr;
              char addrBuf[ MAX(INET_ADDRSTRLEN, INET6_ADDRSTRLEN) ];
              if(addr && (addr->sin_family==AF_INET || addr->sin_family==AF_INET6)) {
                  NSString *name = [NSString stringWithUTF8String:interface->ifa_name];
                  NSString *type;
                  if(addr->sin_family == AF_INET) {
                      if(inet_ntop(AF_INET, &addr->sin_addr, addrBuf, INET_ADDRSTRLEN)) {
                          type = IP_ADDR_IPv4;
                      }
                  } else {
                      const struct sockaddr_in6 *addr6 = (const struct sockaddr_in6*)interface->ifa_addr;
                      if(inet_ntop(AF_INET6, &addr6->sin6_addr, addrBuf, INET6_ADDRSTRLEN)) {
                          type = IP_ADDR_IPv6;
                      }
                  }
                  if(type) {
                      NSString *key = [NSString stringWithFormat:@"%@/%@", name, type];
                      addresses[key] = [NSString stringWithUTF8String:addrBuf];
                  }
              }
          }
          // Free memory
          freeifaddrs(interfaces);
      }
      return [addresses count] ? addresses : nil;
  }
  
  

  • 在其他设备中访问该地址即可

  let address = IPHelper.deviceIPAdress()
  let port = webServer?.port
  http://\(address):\(port)/
  

  • 备注：
    • 确保设备在同一局域网
    • 上传时勿关闭该页面

• Game Over

  局域网中，设备作为server，其他设备作为client，简单的HTTP方式上传文件到server，初始配置的路径即为server接收后存放文件的路径