来看看,我想了好几天了怎么解决呢

catac 2003-08-20 11:41:05
我想做个发消息的东西,可有一个问题,如果一个IP是空的要等很长时间,能不能在发之前先看一下这个IP可不可以连通呢,用什么方法呀,
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雨后阳光2000 2003-08-20
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这是一个完整的Delphi单元,将它加入到你的工程中,你可以调用:


EnumInterfaces(var s string): Boolean;


来返回所有IP地址、网络掩码、广播地址和连接状态。

--------------------------------------------------------------------


unit USock;


interface


uses Windows, Winsock;


{


此函数列举出所有的TCP/IP连接,并返回一个由回车换行(CRLF)符分隔的字符串,包含以下信息:


IP, NetMask, BroadCast-Address, Up/Down status,

Broadcast support, Loopback


如果你将这个字符串赋给TMemo(它的Memo.Lines.Text属性),你可以看到更清晰的结果。


使用此函数,你需要Win98/ME/2K, 95 OSR 2 或者NT service pack #3,因为程序会使用到WinSock 2(WS2_32.DLL)。


}


function EnumInterfaces(var sInt: string): Boolean;


{ 从Winsock 2.0导入函数WSAIOCtl -- 在Win98/ME/2K and 95 OSR2, NT srv pack #3下才有Winsock 2 }


function WSAIoctl(s: TSocket; cmd: DWORD; lpInBuffer: PCHAR; dwInBufferLen:

DWORD;

lpOutBuffer: PCHAR; dwOutBufferLen: DWORD;

lpdwOutBytesReturned: LPDWORD;

lpOverLapped: POINTER;

lpOverLappedRoutine: POINTER): Integer; stdcall; external 'WS2_32.DLL';


{ Constants taken from C header files }


const SIO_GET_INTERFACE_LIST = $4004747F;

IFF_UP = $00000001;

IFF_BROADCAST = $00000002;

IFF_LOOPBACK = $00000004;

IFF_POINTTOPOINT = $00000008;

IFF_MULTICAST = $00000010;


type sockaddr_gen = packed record

AddressIn: sockaddr_in;

filler: packed array[0..7] of char;

end;


type INTERFACE_INFO = packed record

iiFlags: u_long; // Interface flags

iiAddress: sockaddr_gen; // Interface address

iiBroadcastAddress: sockaddr_gen; // Broadcast address

iiNetmask: sockaddr_gen; // Network mask

end;


implementation


{-------------------------------------------------------------------


1. 打开Winsock

2. 创建一个socket

3. 调用WSAIOCtl获取网络连接

4. 对每个连接,获取它的IP、掩码、广播地址、状态

5. 将信息填充到一个由CDLF分隔的字符串中

6. 结束


--------------------------------------------------------------------}


function EnumInterfaces(var sInt: string): Boolean;

var s: TSocket;

wsaD: WSADATA;

NumInterfaces: Integer;

BytesReturned, SetFlags: u_long;

pAddrInet: SOCKADDR_IN;

pAddrString: PCHAR;

PtrA: pointer;

Buffer: array[0..20] of INTERFACE_INFO;

i: Integer;

begin

result := true; // Initialize

sInt := '';


WSAStartup($0101, wsaD); // Start WinSock

// You should normally check

// for errors here :)


s := Socket(AF_INET, SOCK_STREAM, 0); // Open a socket

if (s = INVALID_SOCKET) then exit;


try // Call WSAIoCtl

PtrA := @bytesReturned;

if (WSAIoCtl(s, SIO_GET_INTERFACE_LIST, nil, 0, @Buffer, 1024, PtrA, nil,

nil)

<> SOCKET_ERROR)

then

begin // If ok, find out how

// many interfaces exist


NumInterfaces := BytesReturned div SizeOf(INTERFACE_INFO);


for i := 0 to NumInterfaces - 1 do // For every interface

begin

pAddrInet := Buffer[i].iiAddress.addressIn; // IP ADDRESS

pAddrString := inet_ntoa(pAddrInet.sin_addr);

sInt := sInt + ' IP=' + pAddrString + ',';

pAddrInet := Buffer[i].iiNetMask.addressIn; // SUBNET MASK

pAddrString := inet_ntoa(pAddrInet.sin_addr);

sInt := sInt + ' Mask=' + pAddrString + ',';

pAddrInet := Buffer[i].iiBroadCastAddress.addressIn; // Broadcast addr

pAddrString := inet_ntoa(pAddrInet.sin_addr);

sInt := sInt + ' Broadcast=' + pAddrString + ',';


SetFlags := Buffer[i].iiFlags;

if (SetFlags and IFF_UP) = IFF_UP then

sInt := sInt + ' Interface UP,' // Interface up/down

else

sInt := sInt + ' Interface DOWN,';


if (SetFlags and IFF_BROADCAST) = IFF_BROADCAST then // Broadcasts

sInt := sInt + ' Broadcasts supported,' // supported or

else // not supported

sInt := sInt + ' Broadcasts NOT supported,';


if (SetFlags and IFF_LOOPBACK) = IFF_LOOPBACK then // Loopback or

sInt := sInt + ' Loopback interface'

else

sInt := sInt + ' Network interface'; // normal


sInt := sInt + #13#10; // CRLF between

// each interface

end;

end;

except

end;

//

// Close sockets

//

CloseSocket(s);

WSACleanUp;

result := false;

end;


end.
zjqyb 2003-08-20
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adoquery8 2003-08-20
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如果采用的是c/s,在服务器上转发吧.

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