如何检测网线被拔下、网卡被禁用？局域网内本机网络是否正常工作？？？？

Question

如何检测网线被拔下、网卡被禁用？局域网内本机网络是否正常工作？？？？

Answer 1

右击“网上邻居”，看本地连接的状态，
如果有个红色的X，表示网线被拔下，如果呈灰色，表示网卡被禁用。
PING其他PC的IP，通则表示LAN是正常工作的

Answer 2

LOL。。好像回答都不合楼主本意 -_-!!!

Answer 3

uses WinInetprocedure TForm1.Button1Click(Sender: TObject);
begin
  if InternetCheckConnection('http://www.csdn.net/', 1, 0) then
    edit1.text:= 'Connected'
  else
    edit1.text:= 'Disconnected';
end;

Answer 4

anbeel(番薯好吃，但不宜多吃):
这种方法我试过了不行的。

Answer 5

//参数：IpAddr:检测的IP地址 192.168.0.1
//功能：检测网络是否正常
Function Tfm_angel.CheckNet(IpAddr: string): Boolean;
type        PIPOptionInformation = ^TIPOptionInformation;
        TIPOptionInformation = packed record
                TTL: Byte; // Time To Live (used for traceroute)
                TOS: Byte; // Type Of Service (usually 0)
                Flags: Byte; // IP header flags (usually 0)
                OptionsSize: Byte; // Size of options data (usually 0, max 40)
                OptionsData: PChar; // Options data buffer
        end;        PIcmpEchoReply = ^TIcmpEchoReply;        TIcmpEchoReply = packed record                Address: DWord; // replying address
                Status: DWord; // IP status value (see below)
                RTT: DWord; // Round Trip Time in milliseconds
                DataSize: Word; // reply data size
                Reserved: Word;
                Data: Pointer; // pointer to reply data buffer
                Options: TIPOptionInformation; // reply options
        end;        TIcmpCreateFile = function: THandle; stdcall;
        TIcmpCloseHandle = function(IcmpHandle: THandle): Boolean; stdcall;
        TIcmpSendEcho = function(IcmpHandle: THandle;DestinationAddress: DWord;RequestData: Pointer;RequestSize: Word;RequestOptions: PIPOptionInformation;ReplyBuffer: Pointer;ReplySize: DWord;Timeout: DWord): DWord; stdcall;const
        Size = 32;
        TimeOut = 500;
var        wsadata: TWSAData;
        Address: DWord; // Address of host to contact
        HostName, HostIP: String; // Name and dotted IP of host to contact
        Phe: PHostEnt; // HostEntry buffer for name lookup
        BufferSize, nPkts: Integer;
        pReqData, pData: Pointer;
        pIPE: PIcmpEchoReply; // ICMP Echo reply buffer
        IPOpt: TIPOptionInformation; // IP Options for packet to send
const
        IcmpDLL = 'icmp.dll';
var        hICMPlib: HModule;
        IcmpCreateFile : TIcmpCreateFile;
        IcmpCloseHandle: TIcmpCloseHandle;
        IcmpSendEcho: TIcmpSendEcho;
        hICMP: THandle; // Handle for the ICMP Calls
begin
        // initialise winsock
        Result:=True;
        if WSAStartup(2,wsadata) <> 0 then
               begin
                 Result:=False;
                 halt;
               end;
        // register the icmp.dll stuff
        hICMPlib := loadlibrary(icmpDLL);
        if hICMPlib <> null then
           begin
                @ICMPCreateFile := GetProcAddress(hICMPlib, 'IcmpCreateFile');
                @IcmpCloseHandle:= GetProcAddress(hICMPlib, 'IcmpCloseHandle');
                @IcmpSendEcho:= GetProcAddress(hICMPlib, 'IcmpSendEcho');
                if (@ICMPCreateFile = Nil) or (@IcmpCloseHandle = Nil) or (@IcmpSendEcho = Nil) then
                    begin
                        Result:=False;
                        halt;
                    end;
                hICMP := IcmpCreateFile;
                if hICMP = INVALID_HANDLE_VALUE then
                    begin
                       Result:=False;
                       halt;
                    end;
           end
        else
           begin
                Result:=False;
                halt;
           end;
// ------------------------------------------------------------        Address := inet_addr(PChar(IpAddr));
        if (Address = INADDR_NONE) then
            begin
                Phe := GetHostByName(PChar(IpAddr));
                if Phe = Nil then
                    Result:=False
                else
                  begin
                        Address := longint(plongint(Phe^.h_addr_list^)^);
                        HostName := Phe^.h_name;
                        HostIP := StrPas(inet_ntoa(TInAddr(Address)));
                  end;
            end
         else
            begin                Phe := GetHostByAddr(@Address, 4, PF_INET);
                if Phe = Nil then Result:=False;
            end;
        if Address = INADDR_NONE then
            begin
                Result:=False;
            end;
        // Get some data buffer space and put something in the packet to send
        BufferSize := SizeOf(TICMPEchoReply) + Size;   //
        GetMem(pReqData, Size);
        GetMem(pData, Size);
        GetMem(pIPE, BufferSize);
        FillChar(pReqData^, Size, $AA);
        pIPE^.Data := pData;
        // Finally Send the packet
        FillChar(IPOpt, SizeOf(IPOpt), 0);
        IPOpt.TTL := 64;
        NPkts := IcmpSendEcho(hICMP, Address, pReqData, Size,
        @IPOpt, pIPE, BufferSize, TimeOut);
        if NPkts = 0 then Result:=False;
        // Free those buffers
        FreeMem(pIPE); FreeMem(pData); FreeMem(pReqData);
        // --------------------------------------------------------------
        IcmpCloseHandle(hICMP);
        FreeLibrary(hICMPlib);
        // free winsock
        if WSACleanup <> 0 then Result:=False;
end;