得到本机子网掩码的函数，苯办法 ( 积分: 0 )

function GetNetMask: string;
var
i:integer;
SA: TSecurityAttributes;
SI: TStartupInfo;
PI: TProcessInformation;
StdOutPipeRead, StdOutPipeWrite: THandle;
WasOK: Boolean;
Buffer: array[0..255] of Char;
BytesRead: Cardinal;
WorkDir, Line,CommandLine,mystr: string;
begin
Application.ProcessMessages;
CommandLine:=GetEnvironmentVariable('systemroot')+'/system32/ipconfig.exe';
with SA do
begin
nLength := SizeOf(SA);
bInheritHandle := True;
lpSecurityDescriptor := nil;
end;
// create pipe for standard output redirection
CreatePipe(StdOutPipeRead, // read handle
StdOutPipeWrite, // write handle
@SA, // security attributes
0 // number of bytes reserved for pipe - 0 default
);
try
// Make child process use StdOutPipeWrite as standard out,
// and make sure it does not show on screen.
with SI do
begin
FillChar(SI, SizeOf(SI), 0);
cb := SizeOf(SI);
dwFlags := STARTF_USESHOWWINDOW or STARTF_USESTDHANDLES;
wShowWindow := SW_HIDE;
hStdInput := GetStdHandle(STD_INPUT_HANDLE); // don't redirect std input
hStdOutput := StdOutPipeWrite;
hStdError := StdOutPipeWrite;
end;
// launch the command line compiler
WorkDir := ExtractFilePath(CommandLine);
WasOK := CreateProcess(nil, PChar(CommandLine), nil, nil, True, 0, nil,
PChar(WorkDir), SI, PI);

// Now that the handle has been inherited, close write to be safe.
// We don't want to read or write to it accidentally.
CloseHandle(StdOutPipeWrite);
// if process could be created then handle its output
if not WasOK then
begin
result:='';
exit;
end
else
try
// get all output until dos app finishes
Line := '';
repeat
// read block of characters (might contain carriage returns and line feeds)
WasOK := ReadFile(StdOutPipeRead, Buffer, 255, BytesRead, nil);
// has anything been read?
if BytesRead > 0 then
begin
// finish buffer to PChar
Buffer[BytesRead] := #0;
// combine the buffer with the rest of the last run
Line := Line + Buffer;
end;
until not WasOK or (BytesRead = 0);
// wait for console app to finish (should be already at this point)
WaitForSingleObject(PI.hProcess, INFINITE);
finally
// Close all remaining handles
CloseHandle(PI.hThread);
CloseHandle(PI.hProcess);
end;
finally
mystr:=lowercase(Line);
i:=pos('subnet',mystr)+12;
mystr:=copy(mystr,i,49);
i:=pos(':',mystr);
result:=trim(copy(mystr,i+1,20));
CloseHandle(StdOutPipeRead);
end;
end;