CInternetSession::WriteString writes the file and removes directly - visual-c++

Question

I wrote a dll for an application which wil upload some information from the application via ftp to a server. The upload works fine for most of the files I upload.
There is one file which will upload completely but after the upload it is directly removed from the server (this happens not alway, sometimes the file exists on the server after upload). The file is arround 400 kb, all the other files are smaller.
date and type are two CStrings. Data contains the file content and type the first part of the filename.
CInternetSession session(_T("whtsnXt_dll"));
CFtpConnection* pServer = NULL;
CInternetFile* pFile = NULL;
LPCTSTR pszServerName = _T("servername");
CString fileName = type + L".txt";
int curPos = 0;
CString postData = data;
try
{
CString strServerName;
INTERNET_PORT nPort = 21;
pServer = session.GetFtpConnection(pszServerName, _T("username"), _T("password"), nPort, TRUE);
if (pServer->SetCurrentDirectory(L"goes") == 0) {
// MessageBox::Show("De map bestaat niet", "whtsnXt error", MessageBoxButtons::OK, MessageBoxIcon::Error);
}
pFile = pServer->OpenFile((LPCTSTR)fileName, GENERIC_WRITE);
pFile->WriteString(postData);
pFile->Close();
pServer->Close();
delete pFile;
delete pServer;
}
catch (CInternetException* pEx)
{
//catch errors from WinInet
TCHAR pszError[64];
pEx->GetErrorMessage(pszError, 64);
MessageBox::Show(gcnew String(pszError), "whtsnXt error", MessageBoxButtons::OK, MessageBoxIcon::Error);
}
session.Close();
Does someone know a way to upload that file withoud directly removing?

Answer 1

Try to upload the file in smaller pieces:
int i;
for (i = 0; i < postData.Getlength(); i += 1024)
{
pFile->WriteString(postData.Mid(i, min(1024, postData.Getlength() - i));
}
Just to be sure: data is actually a multi-byte or unicode string and holds no binary data? WriteString will only write till it finds a '\0' character. To upload binary data, use pFile->Write.