Loading QTableWidget using QTimer like batch processing, but application holds

I'm parsing a XML file (size varies between 500K & 90 M) and the output of parse is a QStringList. Each index in the stringlist is split based on a seperator & the data is loaded into the table.
So when I try to load the data into table, the application doesn't respond till the loading is complete. So I decided to do the processing in QTimer. But still the application behaves the same way while the table gets loaded with data. I tried to debug this, but the debugger isn't stopping at the break-point.

This is how I've done -

Code:

---

// cresultstable.h
class CResultsTable : public QTableWidget
{
  Q_OBJECT
public:
  CResultsTable(QString fName, QWidget *parent = 0);
 
private:
  QTimer *batchTimer;
 
  .... // other widgets
 
private slots:
  void batchLoadRecords(string str, int nRow);
 
public slots:
  void loadTable();  // This will be called on signal
};

---

This is how I'm calling timer, timeout() to process data -

Code:

---

// cresultstable.cpp
CResultsTable::CResultsTable(QString fName, QWidget *parent) :
  QTableWidget(parent)
{
  ... // other initializations
  ...
 
  batchTimer = new QTimer(this);
  connect(batchTimer, SIGNAL(timeout()), this, SLOT(batchLoadRecords(string, int)));
};
 
void CResultsTable::loadTable()
{
  XMLParser *xmlParse;
  xmlParse= new XMLParser();
 
  xmlParse->Parse();
  std::vector<std::string> info = xmlParse->GetInfo(); // info contains the data of parsed XML document
 
  int numOfItems = info.size();
  setRowCount(numOfItems);
  batchTimer->start(); // Starting the timer here;
  // Giving timeout of 0 because Qt doc says : "QTimer with a timeout of 0 will time out as soon as all the events 
  //in the window system's event queue have been processed. This can be used to do heavy work while
  //providing a snappy user interface"
 
 
  for(it = info.begin(); it != info.end(); it++)
  {
    std::string str = *it;
    // Here I'm trying to load
    batchLoadRecords(str, nRow);  // Put a break-point here but it's not stopping
    nRow++;
  }
  batchTimer->stop();
  emit sig_LoadComplete();
  delete xmlParse;

---

How do I make the application to behave normally without holding the application event, even while loading data ? Kindly help me with this.
Thank you.

I found a mistake in my code that I was calling batch function again in loop apart from timeout's SLOT. So, I modified my approach, but now the application is crashing.

Code:

---

// cresultstable.h
class CResultsTable : public QTableWidget
{
  Q_OBJECT
public:
  CResultsTable(QString fName, QWidget *parent = 0);
 
private:
  QTimer *batchTimer;
  std::vector<std::string>::iterator it;
  std::vector<std::string>::iterator endOfFile;
  int rowIterator;
 
  .... // other widgets
 
private slots:
  void batchLoadRecords();
 
public slots:
  void loadTable();  // This will be called on signal
};

---

Now I'm not using loop to iterate for each index of the string vector. Instead, I'm calling the batchLoadRecords() in timer's timeout slot only.

Code:

---

// cresultstable.cpp
CResultsTable::CResultsTable(QString fName, QWidget *parent) :
  QTableWidget(parent)
{
  ... // other initializations
  ...
 
  batchTimer = new QTimer(this);
  connect(batchTimer, SIGNAL(timeout()), this, SLOT(batchLoadRecords()));
};
 
void CResultsTable::loadTable()
{
  XMLParser *xmlParse;
  xmlParse= new XMLParser();
 
  xmlParse->Parse();
  std::vector<std::string> info = xmlParse->GetInfo(); // info contains the data of parsed XML document
 
  int numOfItems = info.size();
  setRowCount(numOfItems);
 
  rowIterator = 0;
  it = info.begin();
  endOfFile = info.end();
 
  batchTimer->start(); // Starting the timer here;
 
  delete resultParse;
  resultParse = NULL;
}
 
void CResultsTable::batchLoadRecords()
{
    int temp = 0;
    QStringList txt;
    QString s;
 
    if(it == endOfFile)
    {
        batchTimer->stop();
        emit loadComplete();
        return;
    }
    std::string str = *it;  // Break-point here
 
	// ---------   vv
	// Adding the data into table rows here
	// ---------   ^^
 
    it++;
    rowNumber++;
}

---

I put break-point, but the application crashes and shows some dissembler code.
The stack points at 0

Code:

---

0	RaiseException	KERNELBASE		0x75a1812f	
1	CxxThrowException	MSVCR100		0x6ee8872d	
2	fcloseall	MSVCR100		0x6ee9f30f	
3	com_ximpleware::VTDNav::getXPathStringVal	MyApp		0xfb1c88	
4	com_ximpleware::VTDNav::getXPathStringVal	MyApp		0xfb1f7e	
5	com_ximpleware::VTDNav::getXPathStringVal	MyApp		0xfc3e6a

---

It's solved. I had to make my std::vector<std::string> info as member variable, so that the data in that is not lost after the traverse of the function.
Thank you.