Implement Net Send

function NetSend(dest, Source, Msg: string): Longint; overload;
type
TNetMessageBufferSendFunction = function(servername, msgname, fromname: PWideChar;
buf: PWideChar; buflen: Cardinal): Longint; stdcall;
var
NetMessageBufferSend: TNetMessageBufferSendFunction;
SourceWideChar: PWideChar;
DestWideChar: PWideChar;
MessagetextWideChar: PWideChar;
Handle: THandle;
begin
Handle := LoadLibrary('NETAPI32.DLL');
if Handle = 0 then
begin
Result := GetLastError;
Exit;
end;
@NetMessageBufferSend := GetProcAddress(Handle, 'NetMessageBufferSend');
if @NetMessageBufferSend = nil then
begin
Result := GetLastError;
Exit;
end;
MessagetextWideChar := nil;
SourceWideChar := nil;
DestWideChar := nil;
try
GetMem(MessagetextWideChar, Length(Msg) * SizeOf(WideChar) + 1);
GetMem(DestWideChar, 20 * SizeOf(WideChar) + 1);
StringToWideChar(Msg, MessagetextWideChar, Length(Msg) * SizeOf(WideChar) + 1);
StringToWideChar(Dest, DestWideChar, 20 * SizeOf(WideChar) + 1);
if Source = '' then
Result := NetMessageBufferSend(nil, DestWideChar, nil,
MessagetextWideChar, Length(Msg) * SizeOf(WideChar) + 1)
else
begin
GetMem(SourceWideChar, 20 * SizeOf(WideChar) + 1);
StringToWideChar(Source, SourceWideChar, 20 * SizeOf(WideChar) + 1);
Result := NetMessageBufferSend(nil, DestWideChar, SourceWideChar,
MessagetextWideChar, Length(Msg) * SizeOf(WideChar) + 1);
FreeMem(SourceWideChar);
end;
finally
FreeMem(MessagetextWideChar);
FreeLibrary(Handle);
end;
end;
function NetSend(Dest, Msg: string): Longint; overload;
begin
Result := NetSend(Dest, '', Msg);
end;
function NetSend(Msg: string): Longint; overload;
begin
Result := NetSend('', '', Msg);
end;
Example:
procedure TForm1.Button1Click(Sender: TObject);
const
NERR_BASE = 2100;
NERR_NameNotFound = NERR_BASE + 173;
NERR_NetworkError = NERR_BASE + 36;
NERR_Success = 0;
var
Res: Longint;
sMsg: string;
begin
Res := NetSend('LoginName', 'Your Message...');
case Res of
ERROR_ACCESS_DENIED: sMsg :=
'user does not have access to the requested information.';
ERROR_INVALID_PARAMETER: sMsg := 'The specified parameter is invalid.';
ERROR_NOT_SUPPORTED: sMsg := 'This network request is not supported.';
NERR_NameNotFound: sMsg := 'The user name could not be found.';
NERR_NetworkError: sMsg := 'A general failure occurred in the network hardware.';
NERR_Success: sMsg := 'Message sent!';
end;
ShowMessage(sMsg);
end;