我使用 3G 无线网卡已经有一段时间了，每次连接时，我的防病毒软件都会启动更新。
我想知道我可以使用哪些 Win32 API 函数集来获得通知或查询有关 Internet 连接即将到来的事件？
是否已经有一组用于 Delphi 的移植标头？
【问题讨论】：
标签： delphi winapi wininet internet-connection
查看 WinINet 中的 InternetGetConnectedState。
某些应用程序还可能轮询已知服务器，并且在获得有效连接之前不执行任何操作。
【讨论】：
uses WinInet;
function IsConnected: boolean;
const
// local system uses a modem to connect to the Internet.
INTERNET_CONNECTION_MODEM = 1;
// local system uses a local area network to connect to the Internet.
INTERNET_CONNECTION_LAN = 2;
// local system uses a proxy server to connect to the Internet.
INTERNET_CONNECTION_PROXY = 4;
// local system's modem is busy with a non-Internet connection.
INTERNET_CONNECTION_MODEM_BUSY = 8;
var
dwConnectionTypes : DWORD;
begin
dwConnectionTypes := INTERNET_CONNECTION_MODEM +
INTERNET_CONNECTION_LAN +
INTERNET_CONNECTION_PROXY;
Result := InternetGetConnectedState(@dwConnectionTypes,0);
end;
【讨论】：
我参与了一个项目，只要用户通过 VPN 连接我们的网络，就可以运行他们的登录脚本。为此，我编写了一个辅助单元来检索适配器信息并将其存储到一个简单的记录中。
然后我设置了一个注册表通知，see here for how to do that in Delphi
注册通知在HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces。每次 Windows 获得新的 IP 地址或对适配器连接信息进行任何类型的更改时，都会触发此通知事件。当此事件触发时，我调用了该函数（在下面的代码中）以检索有关适配器的更新信息。我将这个新信息与我之前记录的信息进行了比较...这意味着我必须保存之前的适配器信息查询才能知道是否发生了变化。
总之，这是我的辅助单元：
unit uAdapterInfo;
interface
uses
Classes,
SysUtils;
const
MAX_INTERFACE_NAME_LEN = $100;
ERROR_SUCCESS = 0;
MAXLEN_IFDESCR = $100;
MAXLEN_PHYSADDR = 8;
MIB_IF_OPER_STATUS_NON_OPERATIONAL = 0;
MIB_IF_OPER_STATUS_UNREACHABLE = 1;
MIB_IF_OPER_STATUS_DISCONNECTED = 2;
MIB_IF_OPER_STATUS_CONNECTING = 3;
MIB_IF_OPER_STATUS_CONNECTED = 4;
MIB_IF_OPER_STATUS_OPERATIONAL = 5;
MIB_IF_TYPE_OTHER = 1;
MIB_IF_TYPE_ETHERNET = 6;
MIB_IF_TYPE_TOKENRING = 9;
MIB_IF_TYPE_FDDI = 15;
MIB_IF_TYPE_PPP = 23;
MIB_IF_TYPE_LOOPBACK = 24;
MIB_IF_TYPE_SLIP = 28;
MIB_IF_ADMIN_STATUS_UP = 1;
MIB_IF_ADMIN_STATUS_DOWN = 2;
MIB_IF_ADMIN_STATUS_TESTING = 3;
_MAX_ROWS_ = 20;
ANY_SIZE = 1;
type
MIB_IFROW = record
wszName: array[0 .. (MAX_INTERFACE_NAME_LEN * 2 - 1)] of ansichar;
dwIndex: longint;
dwType: longint;
dwMtu: longint;
dwSpeed: longint;
dwPhysAddrLen: longint;
bPhysAddr: array[0 .. (MAXLEN_PHYSADDR - 1)] of byte;
dwAdminStatus: longint;
dwOperStatus: longint;
dwLastChange: longint;
dwInOctets: longint;
dwInUcastPkts: longint;
dwInNUcastPkts: longint;
dwInDiscards: longint;
dwInErrors: longint;
dwInUnknownProtos: longint;
dwOutOctets: longint;
dwOutUcastPkts: longint;
dwOutNUcastPkts: longint;
dwOutDiscards: longint;
dwOutErrors: longint;
dwOutQLen: longint;
dwDescrLen: longint;
bDescr: array[0 .. (MAXLEN_IFDESCR - 1)] of ansichar;
end;
type
MIB_IPADDRROW = record
dwAddr: longint;
dwIndex: longint;
dwMask: longint;
dwBCastAddr: longint;
dwReasmSize: longint;
unused1: word;
unused2: word;
end;
type
_IfTable = record
nRows: longint;
ifRow: array[1.._MAX_ROWS_] of MIB_IFROW;
end;
type
_IpAddrTable = record
dwNumEntries: longint;
table: array[1..ANY_SIZE] of MIB_IPADDRROW;
end;
function GetIfTable(pIfTable: Pointer; var pdwSize: longint; bOrder: longint): longint;
stdcall;
function GetIpAddrTable(pIpAddrTable: Pointer; var pdwSize: longint;
bOrder: longint): longint; stdcall;
function Get_if_type(iType: integer): string;
function Get_if_admin_status(iStatus: integer): string;
function Get_if_oper_status(iStatus: integer): string;
implementation
function GetIfTable; stdcall; external 'IPHLPAPI.DLL';
function GetIpAddrTable; stdcall; external 'IPHLPAPI.DLL';
function Get_if_type(iType: integer): string;
var
sResult: string;
begin
sResult := 'UNKNOWN';
case iType of
1: sResult := 'Other';
6: sResult := 'Ethernet';
9: sResult := 'Tokenring';
15: sResult := 'FDDI';
23: sResult := 'PPP';
24: sResult := 'Local loopback';
28: sResult := 'SLIP';
37: sResult := 'ATM';
71: sResult := 'IEEE 802.11';
131: sResult := 'Tunnel';
144: sResult := 'IEEE 1394 (Firewire)';
end;
Result := sResult;
end;
function Get_if_admin_status(iStatus: integer): string;
var
sResult: string;
begin
sResult := 'UNKNOWN';
case iStatus of
1: sResult := 'UP';
2: sResult := 'DOWN';
3: sResult := 'TESTING';
end;
Result := sResult;
end;
function Get_if_oper_status(iStatus: integer): string;
var
sResult: string;
begin
sResult := 'UNKNOWN';
case iStatus of
0: sResult := 'NON_OPERATIONAL';
1: sResult := 'UNREACHABLE';
2: sResult := 'DISCONNECTED';
3: sResult := 'CONNECTING';
4: sResult := 'CONNECTED';
5: sResult := 'OPERATIONAL';
end;
Result := sResult;
end;
end.
为了在另一个单元中使用这个单元，我创建了以下函数，它填充了一个名为 TAdapterInfo 的自定义类型（在我的主单元中声明）：
type
TAdapterInfo = array of record
dwIndex: longint;
dwType: longint;
dwMtu: longint;
dwSpeed: extended;
dwPhysAddrLen: longint;
bPhysAddr: string;
dwAdminStatus: longint;
dwOperStatus: longint;
dwLastChange: longint;
dwInOctets: longint;
dwInUcastPkts: longint;
dwInNUcastPkts: longint;
dwInDiscards: longint;
dwInErrors: longint;
dwInUnknownProtos: longint;
dwOutOctets: longint;
dwOutUcastPkts: longint;
dwOutNUcastPkts: longint;
dwOutDiscards: longint;
dwOutErrors: longint;
dwOutQLen: longint;
dwDescrLen: longint;
bDescr: string;
sIpAddress: string;
sIpMask: string;
end;
//////////
function Get_EthernetAdapterDetail(var AdapterDataFound: TAdapterInfo): boolean;
var
pIfTable: ^_IfTable;
pIpTable: ^_IpAddrTable;
ifTableSize, ipTableSize: longint;
tmp: string;
i, j, k, m: integer;
ErrCode: longint;
sAddr, sMask: in_addr;
IPAddresses, IPMasks: TStringList;
sIPAddressLine, sIPMaskLine: string;
bResult: boolean;
begin
bResult := True; //default return value
pIfTable := nil;
pIpTable := nil;
IPAddresses := TStringList.Create;
IPMasks := TStringList.Create;
try
// First: just get the buffer size.
// TableSize returns the size needed.
ifTableSize := 0; // Set to zero so the GetIfTabel function
// won't try to fill the buffer yet,
// but only return the actual size it needs.
GetIfTable(pIfTable, ifTableSize, 1);
if (ifTableSize < SizeOf(MIB_IFROW) + Sizeof(longint)) then
begin
bResult := False;
Result := bResult;
Exit; // less than 1 table entry?!
end;
ipTableSize := 0;
GetIpAddrTable(pIpTable, ipTableSize, 1);
if (ipTableSize < SizeOf(MIB_IPADDRROW) + Sizeof(longint)) then
begin
bResult := False;
Result := bResult;
Exit; // less than 1 table entry?!
end;
// Second:
// allocate memory for the buffer and retrieve the
// entire table.
GetMem(pIfTable, ifTableSize);
ErrCode := GetIfTable(pIfTable, ifTableSize, 1);
if ErrCode <> ERROR_SUCCESS then
begin
bResult := False;
Result := bResult;
Exit; // OK, that did not work.
// Not enough memory i guess.
end;
GetMem(pIpTable, ipTableSize);
ErrCode := GetIpAddrTable(pIpTable, ipTableSize, 1);
if ErrCode <> ERROR_SUCCESS then
begin
bResult := False;
Result := bResult;
Exit;
end;
for k := 1 to pIpTable^.dwNumEntries do
begin
sAddr.S_addr := pIpTable^.table[k].dwAddr;
sMask.S_addr := pIpTable^.table[k].dwMask;
sIPAddressLine := Format('0x%8.8x', [(pIpTable^.table[k].dwIndex)]) +
'=' + Format('%s', [inet_ntoa(sAddr)]);
sIPMaskLine := Format('0x%8.8x', [(pIpTable^.table[k].dwIndex)]) +
'=' + Format('%s', [inet_ntoa(sMask)]);
IPAddresses.Add(sIPAddressLine);
IPMasks.Add(sIPMaskLine);
end;
SetLength(AdapterDataFound, pIfTable^.nRows); //initialize the array or records
for i := 1 to pIfTable^.nRows do
try
//if pIfTable^.ifRow[i].dwType=MIB_IF_TYPE_ETHERNET then
//begin
m := i - 1;
AdapterDataFound[m].dwIndex := 4;//(pIfTable^.ifRow[i].dwIndex);
AdapterDataFound[m].dwType := (pIfTable^.ifRow[i].dwType);
AdapterDataFound[m].dwIndex := (pIfTable^.ifRow[i].dwIndex);
AdapterDataFound[m].sIpAddress :=
IPAddresses.Values[Format('0x%8.8x', [(pIfTable^.ifRow[i].dwIndex)])];
AdapterDataFound[m].sIpMask :=
IPMasks.Values[Format('0x%8.8x', [(pIfTable^.ifRow[i].dwIndex)])];
AdapterDataFound[m].dwMtu := (pIfTable^.ifRow[i].dwMtu);
AdapterDataFound[m].dwSpeed := (pIfTable^.ifRow[i].dwSpeed);
AdapterDataFound[m].dwAdminStatus := (pIfTable^.ifRow[i].dwAdminStatus);
AdapterDataFound[m].dwOperStatus := (pIfTable^.ifRow[i].dwOperStatus);
AdapterDataFound[m].dwInUcastPkts := (pIfTable^.ifRow[i].dwInUcastPkts);
AdapterDataFound[m].dwInNUcastPkts := (pIfTable^.ifRow[i].dwInNUcastPkts);
AdapterDataFound[m].dwInDiscards := (pIfTable^.ifRow[i].dwInDiscards);
AdapterDataFound[m].dwInErrors := (pIfTable^.ifRow[i].dwInErrors);
AdapterDataFound[m].dwInUnknownProtos := (pIfTable^.ifRow[i].dwInUnknownProtos);
AdapterDataFound[m].dwOutNUcastPkts := (pIfTable^.ifRow[i].dwOutNUcastPkts);
AdapterDataFound[m].dwOutUcastPkts := (pIfTable^.ifRow[i].dwOutUcastPkts);
AdapterDataFound[m].dwOutDiscards := (pIfTable^.ifRow[i].dwOutDiscards);
AdapterDataFound[m].dwOutErrors := (pIfTable^.ifRow[i].dwOutErrors);
AdapterDataFound[m].dwOutQLen := (pIfTable^.ifRow[i].dwOutQLen);
AdapterDataFound[m].bDescr := (pIfTable^.ifRow[i].bDescr);
tmp := '';
for j := 0 to pIfTable^.ifRow[i].dwPhysAddrLen - 1 do
begin
if Length(tmp) > 0 then
tmp := tmp + '-' + format('%.2x', [pIfTable^.ifRow[i].bPhysAddr[j]])
else
tmp := tmp + format('%.2x', [pIfTable^.ifRow[i].bPhysAddr[j]]);
end;
if Length(tmp) > 0 then
begin
AdapterDataFound[m].bPhysAddr := tmp;
end;
except
bResult := False;
Result := bResult;
Exit;
end;
finally
if Assigned(pIfTable) then
begin
FreeMem(pIfTable, ifTableSize);
end;
FreeAndNil(IPMasks);
FreeAndNil(IPAddresses);
end;
Result := bResult;
end;
顺便说一句，我还使用这个单元和几乎完全相同的代码来创建ifconfig -a 的副本，其中can be found on github。我这样做主要是为了自学如何完成这项任务。
【讨论】：
这是一个如何使用辅助单元的工作示例。它来自我为模拟“ifconfig -a”而编写的一个小项目。这是一个控制台应用程序项目。
program ifconfig;
{$APPTYPE CONSOLE}
uses
SysUtils,
Classes,
Winsock,
uAdapterInfo in 'uAdapterInfo.pas';
type
TAdapterInfo = array of record
dwIndex: longint;
dwType: longint;
dwMtu: longint;
dwSpeed: extended;
dwPhysAddrLen: longint;
bPhysAddr: string;
dwAdminStatus: longint;
dwOperStatus: longint;
dwLastChange: longint;
dwInOctets: longint;
dwInUcastPkts: longint;
dwInNUcastPkts: longint;
dwInDiscards: longint;
dwInErrors: longint;
dwInUnknownProtos: longint;
dwOutOctets: longint;
dwOutUcastPkts: longint;
dwOutNUcastPkts: longint;
dwOutDiscards: longint;
dwOutErrors: longint;
dwOutQLen: longint;
dwDescrLen: longint;
bDescr: string;
sIpAddress: string;
sIpMask: string;
end;
function Get_EthernetAdapterDetail(var AdapterDataFound: TAdapterInfo): boolean;
var
pIfTable: ^_IfTable;
pIpTable: ^_IpAddrTable;
ifTableSize, ipTableSize: longint;
tmp: string;
i, j, k, m: integer;
ErrCode: longint;
sAddr, sMask: in_addr;
IPAddresses, IPMasks: TStringList;
sIPAddressLine, sIPMaskLine: string;
bResult: boolean;
begin
bResult := True; //default return value
pIfTable := nil;
pIpTable := nil;
IPAddresses := TStringList.Create;
IPMasks := TStringList.Create;
try
// First: just get the buffer size.
// TableSize returns the size needed.
ifTableSize := 0; // Set to zero so the GetIfTabel function
// won't try to fill the buffer yet,
// but only return the actual size it needs.
GetIfTable(pIfTable, ifTableSize, 1);
if (ifTableSize < SizeOf(MIB_IFROW) + Sizeof(longint)) then
begin
bResult := False;
Result := bResult;
Exit; // less than 1 table entry?!
end;
ipTableSize := 0;
GetIpAddrTable(pIpTable, ipTableSize, 1);
if (ipTableSize < SizeOf(MIB_IPADDRROW) + Sizeof(longint)) then
begin
bResult := False;
Result := bResult;
Exit; // less than 1 table entry?!
end;
// Second:
// allocate memory for the buffer and retrieve the
// entire table.
GetMem(pIfTable, ifTableSize);
ErrCode := GetIfTable(pIfTable, ifTableSize, 1);
if ErrCode <> ERROR_SUCCESS then
begin
bResult := False;
Result := bResult;
Exit; // OK, that did not work.
// Not enough memory i guess.
end;
GetMem(pIpTable, ipTableSize);
ErrCode := GetIpAddrTable(pIpTable, ipTableSize, 1);
if ErrCode <> ERROR_SUCCESS then
begin
bResult := False;
Result := bResult;
Exit;
end;
for k := 1 to pIpTable^.dwNumEntries do
begin
sAddr.S_addr := pIpTable^.table[k].dwAddr;
sMask.S_addr := pIpTable^.table[k].dwMask;
sIPAddressLine := Format('0x%8.8x', [(pIpTable^.table[k].dwIndex)]) +
'=' + Format('%s', [inet_ntoa(sAddr)]);
sIPMaskLine := Format('0x%8.8x', [(pIpTable^.table[k].dwIndex)]) +
'=' + Format('%s', [inet_ntoa(sMask)]);
IPAddresses.Add(sIPAddressLine);
IPMasks.Add(sIPMaskLine);
end;
SetLength(AdapterDataFound, pIfTable^.nRows); //initialize the array or records
for i := 1 to pIfTable^.nRows do
try
//if pIfTable^.ifRow[i].dwType=MIB_IF_TYPE_ETHERNET then
//begin
m := i - 1;
AdapterDataFound[m].dwIndex := 4;//(pIfTable^.ifRow[i].dwIndex);
AdapterDataFound[m].dwType := (pIfTable^.ifRow[i].dwType);
AdapterDataFound[m].dwIndex := (pIfTable^.ifRow[i].dwIndex);
AdapterDataFound[m].sIpAddress :=
IPAddresses.Values[Format('0x%8.8x', [(pIfTable^.ifRow[i].dwIndex)])];
AdapterDataFound[m].sIpMask :=
IPMasks.Values[Format('0x%8.8x', [(pIfTable^.ifRow[i].dwIndex)])];
AdapterDataFound[m].dwMtu := (pIfTable^.ifRow[i].dwMtu);
AdapterDataFound[m].dwSpeed := (pIfTable^.ifRow[i].dwSpeed);
AdapterDataFound[m].dwAdminStatus := (pIfTable^.ifRow[i].dwAdminStatus);
AdapterDataFound[m].dwOperStatus := (pIfTable^.ifRow[i].dwOperStatus);
AdapterDataFound[m].dwInUcastPkts := (pIfTable^.ifRow[i].dwInUcastPkts);
AdapterDataFound[m].dwInNUcastPkts := (pIfTable^.ifRow[i].dwInNUcastPkts);
AdapterDataFound[m].dwInDiscards := (pIfTable^.ifRow[i].dwInDiscards);
AdapterDataFound[m].dwInErrors := (pIfTable^.ifRow[i].dwInErrors);
AdapterDataFound[m].dwInUnknownProtos := (pIfTable^.ifRow[i].dwInUnknownProtos);
AdapterDataFound[m].dwOutNUcastPkts := (pIfTable^.ifRow[i].dwOutNUcastPkts);
AdapterDataFound[m].dwOutUcastPkts := (pIfTable^.ifRow[i].dwOutUcastPkts);
AdapterDataFound[m].dwOutDiscards := (pIfTable^.ifRow[i].dwOutDiscards);
AdapterDataFound[m].dwOutErrors := (pIfTable^.ifRow[i].dwOutErrors);
AdapterDataFound[m].dwOutQLen := (pIfTable^.ifRow[i].dwOutQLen);
AdapterDataFound[m].bDescr := (pIfTable^.ifRow[i].bDescr);
tmp := '';
for j := 0 to pIfTable^.ifRow[i].dwPhysAddrLen - 1 do
begin
if Length(tmp) > 0 then
tmp := tmp + '-' + format('%.2x', [pIfTable^.ifRow[i].bPhysAddr[j]])
else
tmp := tmp + format('%.2x', [pIfTable^.ifRow[i].bPhysAddr[j]]);
end;
if Length(tmp) > 0 then
begin
AdapterDataFound[m].bPhysAddr := tmp;
end;
except
bResult := False;
Result := bResult;
Exit;
end;
finally
if Assigned(pIfTable) then
begin
FreeMem(pIfTable, ifTableSize);
end;
FreeAndNil(IPMasks);
FreeAndNil(IPAddresses);
end;
Result := bResult;
end;
var
AdapterData: TAdapterInfo;
i: integer;
begin
try
WriteLn('');
if Get_EthernetAdapterDetail(AdapterData) then
begin
for i := 0 to Length(AdapterData) - 1 do
begin
WriteLn(Format('0x%8.8x', [AdapterData[i].dwIndex]));
WriteLn('"' + AdapterData[i].bDescr + '"');
Write(Format(#9 + 'Link encap: %s ', [Get_if_type(AdapterData[i].dwType)]));
if Length(AdapterData[i].bPhysAddr) > 0 then
Write('HWaddr: ' + AdapterData[i].bPhysAddr);
Write(#13 + #10 + #9 + 'inet addr:' + AdapterData[i].sIpAddress);
WriteLn(' Mask: ' + AdapterData[i].sIpMask);
WriteLn(Format(#9 + 'MTU: %d Speed:%.2f Mbps', [AdapterData[i].dwMtu,
(AdapterData[i].dwSpeed) / 1000 / 1000]));
Write(#9 + 'Admin status:' + Get_if_admin_status(AdapterData[i].dwAdminStatus));
WriteLn(' Oper status:' + Get_if_oper_status(AdapterData[i].dwOperStatus));
WriteLn(#9 + Format('RX packets:%d dropped:%d errors:%d unkown:%d',
[AdapterData[i].dwInUcastPkts + AdapterData[i].dwInNUcastPkts,
AdapterData[i].dwInDiscards, AdapterData[i].dwInErrors,
AdapterData[i].dwInUnknownProtos]));
WriteLn(#9 + Format('TX packets:%d dropped:%d errors:%d txqueuelen:%d',
[AdapterData[i].dwOutUcastPkts + AdapterData[i].dwOutNUcastPkts,
AdapterData[i].dwOutDiscards, AdapterData[i].dwOutErrors,
AdapterData[i].dwOutQLen]));
WriteLn('');
end;
end
else
begin
WriteLn(#13+#10+'*** Error retrieving adapter information');
end;
except
on E: Exception do
Writeln(E.ClassName, ': ', E.Message);
end;
end.
【讨论】：