Use of QProgressBar in Thread

[merry]

Hi All

Working on Qt4.4.3, using my intel mac machine. What I am trying to do is,
I am selecting a file/folder using QFileDialog, and open that file in read write mode and writing that file with some other text, For this process I am using thread, I am selecting file in one class, and after selection i called thread , Using thread , I called some other class for writing on that selected file . For writing on the file, i want to run progressBar, till the writing completes, but its not working, i dont know why,

void ClassWrite::fnWriteFile(FILE *fp, int nFillWith)
{
       unsigned long value = 0;
	int iProgressCounter = 0;
	long long llSizeRead = 0;
	unsigned long SizetoRead =0;
	long long SizeRead = 0;
	QFileInfo filename(m_FileName);
	llSizeRead = filename.size();
	QString strMessage = "";
	unsigned char *pBuffer = NULL;
	unsigned long dwBufferValue = 4*1024*1024;
	pBuffer = (unsigned char *)calloc(dwBufferValue,sizeof(unsigned char));
     if(pBuffer == NULL)
	 return;
 
	 strMessage = "WritingFile " + m_FileName;
	 emit ProgressMaximumValue(100);
	 qApp->processEvents(); 
 
	while(llSizeRead>0)
	{
	  if(bStopFlag)
		break;
 
 
	 if(llSizeRead>dwBufferValue)
	 {
	    SizetoRead = dwBufferValue;
		value = ((SizetoRead/llSizeRead)*100);
		if(iProgressCounter == 0 || iProgressCounter == 100)
		{
	               emit SetProgressValue(strMessage,value);
		       qApp->processEvents();
		       memset(pBuffer,nFillWith,SizetoRead);
			fseek(fp, 0+SizeRead, SEEK_CUR);
			fwrite((void*)pBuffer,SizetoRead,1,fp);
			llSizeRead-=SizetoRead;
			SizeRead = SizetoRead;
			iProgressCounter = 0;
		 }
		iProgressCounter++;
	 }
	  else
	  {
		SizetoRead = llSizeRead;
		value = ((SizetoRead/llSizeRead)*100);
	    if(iProgressCounter == 0 || iProgressCounter == 100)
	    {
		    emit SetProgressValue(strMessage,value);
		    qApp->processEvents();
		    memset(pBuffer,nFillWith,SizetoRead);
		    fseek(fp, 0+SizeRead, SEEK_CUR);
		    fwrite((void*)pBuffer,SizetoRead,1,fp);
		    llSizeRead-=SizetoRead;
	            SizeRead = SizetoRead;
		    iProgressCounter = 0;
	    }
		 iProgressCounter++;
	  }
 
 
	}
 
	    fflush(fp);
		if(pBuffer)
		{
		  free(pBuffer);
		  pBuffer = NULL; 
		}
}

void ClassWrite::fnWriteFile(FILE *fp, int nFillWith)
{
       unsigned long value = 0;
	int iProgressCounter = 0;
	long long llSizeRead = 0;
	unsigned long SizetoRead =0;
	long long SizeRead = 0;
	QFileInfo filename(m_FileName);
	llSizeRead = filename.size();
	QString strMessage = "";
	unsigned char *pBuffer = NULL;
	unsigned long dwBufferValue = 4*1024*1024;
	pBuffer = (unsigned char *)calloc(dwBufferValue,sizeof(unsigned char));
     if(pBuffer == NULL)
	 return;
	 
	 strMessage = "WritingFile " + m_FileName;
	 emit ProgressMaximumValue(100);
	 qApp->processEvents(); 
	
	while(llSizeRead>0)
	{
	  if(bStopFlag)
		break;
		
	
	 if(llSizeRead>dwBufferValue)
	 {
	    SizetoRead = dwBufferValue;
		value = ((SizetoRead/llSizeRead)*100);
		if(iProgressCounter == 0 || iProgressCounter == 100)
		{
	               emit SetProgressValue(strMessage,value);
		       qApp->processEvents();
		       memset(pBuffer,nFillWith,SizetoRead);
			fseek(fp, 0+SizeRead, SEEK_CUR);
			fwrite((void*)pBuffer,SizetoRead,1,fp);
			llSizeRead-=SizetoRead;
			SizeRead = SizetoRead;
			iProgressCounter = 0;
		 }
		iProgressCounter++;
	 }
	  else
	  {
		SizetoRead = llSizeRead;
		value = ((SizetoRead/llSizeRead)*100);
	    if(iProgressCounter == 0 || iProgressCounter == 100)
	    {
		    emit SetProgressValue(strMessage,value);
		    qApp->processEvents();
		    memset(pBuffer,nFillWith,SizetoRead);
		    fseek(fp, 0+SizeRead, SEEK_CUR);
		    fwrite((void*)pBuffer,SizetoRead,1,fp);
		    llSizeRead-=SizetoRead;
	            SizeRead = SizetoRead;
		    iProgressCounter = 0;
	    }
		 iProgressCounter++;
	  }

	  
	}
	
	    fflush(fp);
		if(pBuffer)
		{
		  free(pBuffer);
		  pBuffer = NULL; 
		}
}

To copy to clipboard, switch view to plain text mode 

Pls suggest me something

[spirit]

try something like this

class AnotherThread: public QThread
{
    Q_OBJECT
 
signals:
    void valueChanged(int);
 
public:
    AnotherThread(QObject *parent, int val)
        : QThread(parent),
        m_currentVal(val)
    {
    }
 
protected:
    virtual void run() {  
        for (int i = 0; i < m_currentVal; ++i)
            emit valueChanged(i); 
    }
 
private:
    int m_currentVal;
};
 
class MainWindow:public QMainWindow
{
    Q_OBJECT
 
public:
    MainWindow::MainWindow(QWidget *parent = 0) 
        : QMainWindow(parent)
    {
        QHBoxLayout *mainLayout = new QHBoxLayout();
 
        m_pbProgress = new QProgressBar();
        m_pbProgress->setMinimum(0);
        m_pbProgress->setMaximum(100);
 
        m_at = new AnotherThread(this, m_pbProgress->maximum());
        connect(m_at, SIGNAL(valueChanged(int)), m_pbProgress, SLOT(setValue(int)));
 
        QPushButton *pbRun = new QPushButton("Run");
        connect(pbRun, SIGNAL(clicked()), m_at, SLOT(start()));
 
        mainLayout->addWidget(m_pbProgress);
        mainLayout->addWidget(pbRun);
 
        QWidget *central = new QWidget();
        central->setLayout(mainLayout);
        setCentralWidget(central);
    }
 
private:
    QProgressBar *m_pbProgress;
    AnotherThread *m_at;
};

class AnotherThread: public QThread
{
    Q_OBJECT

signals:
    void valueChanged(int);

public:
    AnotherThread(QObject *parent, int val)
        : QThread(parent),
        m_currentVal(val)
    {
    }

protected:
    virtual void run() {  
        for (int i = 0; i < m_currentVal; ++i)
            emit valueChanged(i); 
    }

private:
    int m_currentVal;
};

class MainWindow:public QMainWindow
{
    Q_OBJECT

public:
    MainWindow::MainWindow(QWidget *parent = 0) 
        : QMainWindow(parent)
    {
        QHBoxLayout *mainLayout = new QHBoxLayout();

        m_pbProgress = new QProgressBar();
        m_pbProgress->setMinimum(0);
        m_pbProgress->setMaximum(100);

        m_at = new AnotherThread(this, m_pbProgress->maximum());
        connect(m_at, SIGNAL(valueChanged(int)), m_pbProgress, SLOT(setValue(int)));

        QPushButton *pbRun = new QPushButton("Run");
        connect(pbRun, SIGNAL(clicked()), m_at, SLOT(start()));

        mainLayout->addWidget(m_pbProgress);
        mainLayout->addWidget(pbRun);

        QWidget *central = new QWidget();
        central->setLayout(mainLayout);
        setCentralWidget(central);
    }

private:
    QProgressBar *m_pbProgress;
    AnotherThread *m_at;
};

To copy to clipboard, switch view to plain text mode 

[wysota]

Wow... what a C-ish code What do you use threads for? You don't need them if all you want to do is copy some data.