Question

该函数总是返回nil，如果我打印接口名称没有名称“en0”。我需要获取设备的本地ipaddress，我该怎么办？

func getWiFiAddress() -> String? {
var address : String?

// Get list of all interfaces on the local machine:
var ifaddr : UnsafeMutablePointer<ifaddrs>?
guard getifaddrs(&ifaddr) == 0 else { return nil }
guard let firstAddr = ifaddr else { return nil }

// For each interface ...
for ifptr in sequence(first: firstAddr, next: { $0.pointee.ifa_next }) {
    let interface = ifptr.pointee

    // Check for IPv4 or IPv6 interface:
    let addrFamily = interface.ifa_addr.pointee.sa_family
    if addrFamily == UInt8(AF_INET) || addrFamily == UInt8(AF_INET6) {

        // Check interface name:
        let name = String(cString: interface.ifa_name)
        if  name == "en0" {

            // Convert interface address to a human readable string:
            var hostname = [CChar](repeating: 0, count: Int(NI_MAXHOST))
            getnameinfo(interface.ifa_addr, socklen_t(interface.ifa_addr.pointee.sa_len),
                        &hostname, socklen_t(hostname.count),
                        nil, socklen_t(0), NI_NUMERICHOST)
            address = String(cString: hostname)
        }
    }
}
freeifaddrs(ifaddr)

return address

}

Answer 1

您没有为ifaddr设置任何值。

Answer 2

而不是en0我将其更改为en1并且它获取我的本地IP地址....原因是en0用于有线或以太网，对于无线我们需要使用en1。

Answer 3

您需要使用

lo0的

用于本地地址

func getWiFiAddress() -> String? {
    // Get list of all interfaces on the local machine:
    var ifaddr : UnsafeMutablePointer<ifaddrs>?
    guard getifaddrs(&ifaddr) == 0 else { return nil }
    guard let firstAddr = ifaddr else { return nil }

    // For each interface ...
    for ifptr in sequence(first: firstAddr, next: { $0.pointee.ifa_next }) {
        let interface = ifptr.pointee

        // Check for IPv4 or IPv6 interface:
        let addrFamily = interface.ifa_addr.pointee.sa_family
        if addrFamily == UInt8(AF_INET) || addrFamily == UInt8(AF_INET6) {

            // Check interface name:
            let name = String(cString: interface.ifa_name)
            if  name == "lo0" {

                // Convert interface address to a human readable string:
                var hostname = [CChar](repeating: 0, count: Int(NI_MAXHOST))
                getnameinfo(interface.ifa_addr, socklen_t(interface.ifa_addr.pointee.sa_len),
                            &hostname, socklen_t(hostname.count),
                            nil, socklen_t(0), NI_NUMERICHOST)
                freeifaddrs(ifaddr)
                return String(cString: hostname)
            }
        }
    }
    return nil
}

函数getWiFiAddress（）总是返回nil？

3 个答案: