Delphi 7 Indy Komponent

[mrmarman]

Size bir kolaylık. 

* Indy kullanmadan SSL desteği : ( örnekte dolar kuru okunur ve ekrana mesaj olarak gösterilir )
* Parse örnek için el yordamıyla yapıldı. XML node name/value olarak okumak daha sağlıklı olur.

Uses WinInet;

function GetUrlSource( aUrl : String; aStream: TStringStream ): Boolean;
var
  hService      : HINTERNET;
  hSession      : HINTERNET;
  lpBuffer      : array[0..1023] of Byte;
  dwBytesRead   : DWORD;
  dwBytesAvail  : DWORD;
  dwTimeOut     : DWORD;
  Sessionname   : String;
begin
  Result        := False;
  if NOT Assigned(aStream) then exit;

  Sessionname   := 'TCMB_Session_' + DateTimeToStr(now);
  hSession      := InternetOpen( PChar(Sessionname), INTERNET_OPEN_TYPE_PRECONFIG, nil, nil, 0 );
  if not Assigned(hSession) then Exit;
  try
    hService := InternetOpenUrl(hSession, PChar(aUrl), nil, 0, INTERNET_FLAG_RELOAD, 0);
    if hService = nil then
      Exit;
    try
      dwTimeOut := 60000; // a minute
      InternetSetOption(hService, INTERNET_OPTION_RECEIVE_TIMEOUT, @dwTimeOut, SizeOf(dwTimeOut));
      if InternetQueryDataAvailable(hService, dwBytesAvail, 0, 0) then
        while ( InternetReadFile(hService, @lpBuffer[0], SizeOf(lpBuffer), dwBytesRead) )
          and ( dwBytesRead <> 0 )
            do aStream.WriteBuffer(lpBuffer[0], dwBytesRead);

      aStream.Position := 0; // ready to use
      Result := aStream.Size > 0;
    finally
      InternetCloseHandle(hService);
    end;
  finally
    InternetCloseHandle(hSession);
  end;
end;

Kullanımı :

procedure TForm1.Button1Click(Sender: TObject);
Const
  LUrl = 'https://www.tcmb.gov.tr/kurlar/today.xml';
var
  LContent  : String;
  LSS       : TStringStream;
  LSrc,
  LBanknoteBuying,
  LBanknoteSelling : String;
begin
  LSS := TStringStream.Create('');
  try
    GetUrlSource( LUrl, LSS );
    LContent := LSS.DataString;
    LSrc := 'CurrencyCode="USD">';
    if Pos(LSrc, LContent) > 0 then
    begin
      Delete(LContent, 1, Pos(LSrc, LContent) + Length(LSrc)-1);
      LContent := Copy( LContent, 1, Pos('</Currency>', LContent)-1);

      LSrc := '<BanknoteBuying>';
      if Pos(LSrc, LContent) > 0 then
      begin
        Delete(LContent, 1, Pos(LSrc, LContent) + Length(LSrc)-1);
        LBanknoteBuying := Copy(LContent, 1, Pos('<', LContent)-1 );
      end;

      LSrc := '<BanknoteSelling>';
      if Pos(LSrc, LContent) > 0 then
      begin
        Delete(LContent, 1, Pos(LSrc, LContent) + Length(LSrc)-1);
        LBanknoteSelling := Copy(LContent, 1, Pos('<', LContent)-1 );
      end;
      ShowmessageFmt('USD Alış : %s  Satış : %s', [ LBanknoteBuying, LBanknoteSelling ]);
    end;
  finally
    FreeAndNil(LSS);
  end;
end;