How to use a file to setup a QProgressDialog, Thanks

[HelloDan]

Hi, all.
I want to read a plaintext file in my program, and show a QProgressDialog during reading. But i don't know how to detect the size of my file to set it up.

It must be a very simple question. But i have not idea about it. Could anyone help?
Thanks for any help!

[talk2amulya]

use size() of QFile..next, depending upon the number of bytes read compared to total size, call setValue()

[HelloDan]

use size() of QFile..next, depending upon the number of bytes read compared to total size, call setValue()

Thanks! I will try.

[HelloDan]

use size() of QFile..next, depending upon the number of bytes read compared to total size, call setValue()

That's a problem, is that any way to try my thinking in a console window? I want to try QProgressDialog in a console window.

Thanks

[talk2amulya]

why would u want a QProgressDialog in a console window?

[HelloDan]

Try to test if my code works.

Do you have any good ways to test?

[HelloDan]

why would u want a QProgressDialog in a console window?

Is it OK? I wrote it in this way, just for try

QFile file("in.txt");
  QTextStream in(&file);
 
     QProgressDialog progressDialog();
     progressDialog.setCancelButtonText(tr("&Cancel"));
     progressDialog.setRange(0, file.size());
     progressDialog.setWindowTitle(tr("Loading..."));
     QString line;
     while(file.pos()<file.size())
     {
        progressDialog.setValue(file.pos());
         progressDialog.setLabelText(tr("Searching file number %1 of %2...")
                                     .arg(file.pos()).arg(file.size()));
         qApp->processEvents();
 
         if (progressDialog.wasCanceled())
             break;
        line=in.readLine();
 
     }

QFile file("in.txt");
  QTextStream in(&file);
  
     QProgressDialog progressDialog();
     progressDialog.setCancelButtonText(tr("&Cancel"));
     progressDialog.setRange(0, file.size());
     progressDialog.setWindowTitle(tr("Loading..."));
     QString line;
     while(file.pos()<file.size())
     {
        progressDialog.setValue(file.pos());
         progressDialog.setLabelText(tr("Searching file number %1 of %2...")
                                     .arg(file.pos()).arg(file.size()));
         qApp->processEvents();

         if (progressDialog.wasCanceled())
             break;
        line=in.readLine();
	
     }

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[talk2amulya]

looks good..isnt it working?

[HelloDan]

looks good..isnt it working?

Thanks. I have try the code in my app. That segment of my code may be OK.
But that is still some problems.

1 I use QFileDialog::getOpenFileName to get a file. But i doesn't reveal immediately in the QComboBox, but it does in the comboBox which I can use my mouse to select it from the drop down list. I post my code in the following. Why?

void DataConvertor::inputFileNameBrowse()
{
    QString initialName=inputFileNameComboBox->currentText(); 
    if(initialName.isEmpty())
    	initialName=QDir::homePath();	 
    QString inputFileName=QFileDialog::getOpenFileName(this,
                                tr("Open file"), initialName);
    inputFileName=QDir::toNativeSeparators(inputFileName);
 
 
    if(!inputFileName.isEmpty())
    {
    	inputFileNameComboBox->addItem(inputFileName);
    	//when it's empty, the index is 0.
    	inputFileNameComboBox->setCurrentIndex(inputFileNameComboBox->currentIndex() + 1);
    	//inputFileNameComboBox->activated(inputFileNameComboBox->currentIndex());
 
    // set output file the same location with the inputFile if it is empty.
    if(outputFileDirectoryComboBox->currentText().isEmpty())
    	{
    	  	outputFileDirectoryComboBox->addItem(QDir::toNativeSeparators(QFileInfo(inputFileName).path()));
          outputFileDirectoryComboBox->setCurrentIndex(outputFileDirectoryComboBox->currentIndex() + 1); 
          //outputFileDirectoryComboBox->activated(outputFileDirectoryComboBox->currentIndex()); 
    	}
 
    	okButton->setEnabled(true);  // enable the ok button    	
    }    	
}

void DataConvertor::inputFileNameBrowse()
{
    QString initialName=inputFileNameComboBox->currentText(); 
    if(initialName.isEmpty())
    	initialName=QDir::homePath();	 
    QString inputFileName=QFileDialog::getOpenFileName(this,
                                tr("Open file"), initialName);
    inputFileName=QDir::toNativeSeparators(inputFileName);
    
     	
    if(!inputFileName.isEmpty())
    {
    	inputFileNameComboBox->addItem(inputFileName);
    	//when it's empty, the index is 0.
    	inputFileNameComboBox->setCurrentIndex(inputFileNameComboBox->currentIndex() + 1);
    	//inputFileNameComboBox->activated(inputFileNameComboBox->currentIndex());
    	
    // set output file the same location with the inputFile if it is empty.
    if(outputFileDirectoryComboBox->currentText().isEmpty())
    	{
    	  	outputFileDirectoryComboBox->addItem(QDir::toNativeSeparators(QFileInfo(inputFileName).path()));
          outputFileDirectoryComboBox->setCurrentIndex(outputFileDirectoryComboBox->currentIndex() + 1); 
          //outputFileDirectoryComboBox->activated(outputFileDirectoryComboBox->currentIndex()); 
    	}
              	
    	okButton->setEnabled(true);  // enable the ok button    	
    }    	
}

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[HelloDan]

looks good..isnt it working?

2 This's problem is about the QProgressDialog. Only When I click the OK button for several times could my program works, it will turn up several QprogressDialogs. Also, That is not output file, I cann't find it.

Thanks!

DataConvertor::DataConvertor(QWidget *parent):QDialog(parent)
{
  setupUi(this);
  okButton->setEnabled(false);  // disable OK button
 
  connect(inputFileBrowseButton,SIGNAL(clicked()),this,SLOT(inputFileNameBrowse()));
  connect(outputFileBrowseButton,SIGNAL(clicked()),this,SLOT(outputFileDirectoryBrowse()));
  connect(aboutButton,SIGNAL(clicked()),this,SLOT(aboutinfo()));
  connect(okButton,SIGNAL(clicked()),this,SLOT(processFile()));
 
}
 
 
void DataConvertor::processFile()
{
  QString fileName=inputFileNameComboBox->currentText();
  if(fileName.isEmpty())
  {
     QMessageBox::information(this,tr("Data Convertor"),tr("Not such a file, Please reselect a file."),QMessageBox::Ok);
  }
  else
  {
    QFile file(fileName);
    //Open read file.
    if(!file.open(QIODevice::ReadOnly))
    {
      QMessageBox::information(this,tr("Data Convertor"),tr("Cann't read file %1:\n%2.").arg(file.fileName()).arg(file.errorString()),QMessageBox::Cancel);
      return;	
    }
    //Open write directory.
    QString outDirName=outputFileDirectoryComboBox->currentText();
    QDir outDir(outDirName);
    ///
    //if the directory is not existed, create one.
    if(!outDir.exists())  
    {
       	outDir.mkpath(outDirName);
    }
 
    QTextStream in(&file);
 
    // form outfile name.       
    QString path=outDirName+QDir::separator()+"abc.txt";
    QFile outFile(path);
    QTextStream out(&outFile);
 
     // setup QProgressDailog
     QProgressDialog progressDialog(this);
     progressDialog.setCancelButtonText(tr("&Cancel"));
     progressDialog.setRange(0, file.size());
     progressDialog.setWindowTitle(tr("Loading..."));
     QString line;
 
    while(file.pos()<file.size())
    {
      	 progressDialog.setValue(file.pos());
         progressDialog.setLabelText(tr("Searching file number %1 of %2...")
                                     .arg(file.pos()).arg(file.size()));
         qApp->processEvents();
 
         if (progressDialog.wasCanceled())
             break;
         line=in.readLine();
         out<<line;
     }      	
  }	
}

DataConvertor::DataConvertor(QWidget *parent):QDialog(parent)
{
  setupUi(this);
  okButton->setEnabled(false);  // disable OK button
  
  connect(inputFileBrowseButton,SIGNAL(clicked()),this,SLOT(inputFileNameBrowse()));
  connect(outputFileBrowseButton,SIGNAL(clicked()),this,SLOT(outputFileDirectoryBrowse()));
  connect(aboutButton,SIGNAL(clicked()),this,SLOT(aboutinfo()));
  connect(okButton,SIGNAL(clicked()),this,SLOT(processFile()));
  
}


void DataConvertor::processFile()
{
  QString fileName=inputFileNameComboBox->currentText();
  if(fileName.isEmpty())
  {
     QMessageBox::information(this,tr("Data Convertor"),tr("Not such a file, Please reselect a file."),QMessageBox::Ok);
  }
  else
  {
    QFile file(fileName);
    //Open read file.
    if(!file.open(QIODevice::ReadOnly))
    {
      QMessageBox::information(this,tr("Data Convertor"),tr("Cann't read file %1:\n%2.").arg(file.fileName()).arg(file.errorString()),QMessageBox::Cancel);
      return;	
    }
    //Open write directory.
    QString outDirName=outputFileDirectoryComboBox->currentText();
    QDir outDir(outDirName);
    ///
    //if the directory is not existed, create one.
    if(!outDir.exists())  
    {
       	outDir.mkpath(outDirName);
    }
    
    QTextStream in(&file);
       
    // form outfile name.       
    QString path=outDirName+QDir::separator()+"abc.txt";
    QFile outFile(path);
    QTextStream out(&outFile);
    
     // setup QProgressDailog
     QProgressDialog progressDialog(this);
     progressDialog.setCancelButtonText(tr("&Cancel"));
     progressDialog.setRange(0, file.size());
     progressDialog.setWindowTitle(tr("Loading..."));
     QString line;

    while(file.pos()<file.size())
    {
      	 progressDialog.setValue(file.pos());
         progressDialog.setLabelText(tr("Searching file number %1 of %2...")
                                     .arg(file.pos()).arg(file.size()));
         qApp->processEvents();
 
         if (progressDialog.wasCanceled())
             break;
         line=in.readLine();
         out<<line;
     }      	
  }	
}

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[talk2amulya]

although i dont understand clearly what ur problem is, but use:

void QComboBox::setEditText ( const QString & text )   [slot]
 
Sets the text in the combobox's text edit.

void QComboBox::setEditText ( const QString & text )   [slot]

Sets the text in the combobox's text edit.

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instead of setCurrentIndex() in both combo boxes..ur problem should solve

[talk2amulya]

dont disable OK button in DataConverter, disable it at the start of processFile() and enable it again at the end of it.

[HelloDan]

dont disable OK button in DataConverter, disable it at the start of processFile() and enable it again at the end of it.

Thanks very much! I had tried. It works.

But the QComboBox drop down list problem is still that.

By the way, how can i start a new line in the file, what about in this way: out<<line<<"\n";
I find the following code doesn't work properly, the data is out of order and miss some

while(file.pos()<file.size())
    {
      	 progressDialog.setValue(file.pos());
         progressDialog.setLabelText(tr("Processing file number %1 of %2...")
                                     .arg(file.pos()).arg(file.size()));
         qApp->processEvents();
 
         if (progressDialog.wasCanceled())
             break;
         line=in.readLine();
         out<<line<<"\n";
     }

while(file.pos()<file.size())
    {
      	 progressDialog.setValue(file.pos());
         progressDialog.setLabelText(tr("Processing file number %1 of %2...")
                                     .arg(file.pos()).arg(file.size()));
         qApp->processEvents();
 
         if (progressDialog.wasCanceled())
             break;
         line=in.readLine();
         out<<line<<"\n";
     }

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[talk2amulya]

could u tell EXACTLY what the problem is..i m still not clear about it

[HelloDan]

could u tell EXACTLY what the problem is..i m still not clear about it

void DataConvertor::inputFileNameBrowse()
{
    QString initialName=inputFileNameComboBox->currentText(); 
    if(initialName.isEmpty())
    	initialName=QDir::homePath();	 
    QString inputFileName=QFileDialog::getOpenFileName(this,
                                tr("Open file"), initialName);
    inputFileName=QDir::toNativeSeparators(inputFileName);
 
 
    if(!inputFileName.isEmpty())
    {
    	inputFileNameComboBox->addItem(inputFileName);
    	//when it's empty, the index is 0.
    	inputFileNameComboBox->setCurrentIndex(inputFileNameComboBox->currentIndex() + 1);
    	//inputFileNameComboBox->activated(inputFileNameComboBox->currentIndex());
 
    // set output file the same location with the inputFile if it is empty.
    if(outputFileDirectoryComboBox->currentText().isEmpty())
    	{
    	  	outputFileDirectoryComboBox->addItem(QDir::toNativeSeparators(QFileInfo(inputFileName).path()));
          outputFileDirectoryComboBox->setCurrentIndex(outputFileDirectoryComboBox->currentIndex() + 1); 
          //outputFileDirectoryComboBox->activated(outputFileDirectoryComboBox->currentIndex()); 
    	}
 
    	okButton->setEnabled(true);  // enable the ok button    	
    }    	
}

void DataConvertor::inputFileNameBrowse()
{
    QString initialName=inputFileNameComboBox->currentText(); 
    if(initialName.isEmpty())
    	initialName=QDir::homePath();	 
    QString inputFileName=QFileDialog::getOpenFileName(this,
                                tr("Open file"), initialName);
    inputFileName=QDir::toNativeSeparators(inputFileName);
    
     	
    if(!inputFileName.isEmpty())
    {
    	inputFileNameComboBox->addItem(inputFileName);
    	//when it's empty, the index is 0.
    	inputFileNameComboBox->setCurrentIndex(inputFileNameComboBox->currentIndex() + 1);
    	//inputFileNameComboBox->activated(inputFileNameComboBox->currentIndex());
    	
    // set output file the same location with the inputFile if it is empty.
    if(outputFileDirectoryComboBox->currentText().isEmpty())
    	{
    	  	outputFileDirectoryComboBox->addItem(QDir::toNativeSeparators(QFileInfo(inputFileName).path()));
          outputFileDirectoryComboBox->setCurrentIndex(outputFileDirectoryComboBox->currentIndex() + 1); 
          //outputFileDirectoryComboBox->activated(outputFileDirectoryComboBox->currentIndex()); 
    	}
              	
    	okButton->setEnabled(true);  // enable the ok button    	
    }    	
}

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In this function, after i use QFileDialog::getOpenFileName to select a file, the combox should contain the file path. But the QComboBox is empty. But I can find the file which i select using the mouse in the drop down list. At the same time, I set the same path to outputFileDirectoryComboBox, it was also hidden in the drop down list. Why?


By the way, how can i start a new line in the file, what about in this way: out<<line<<"\n";
I find the following code doesn't work properly, the data is out of order and miss some


Thanks

[talk2amulya]

ok, regarding combobox problem, use

inputFileNameComboBox->setCurrentIndex(inputFileNameComboBox->count() - 1);
 and
 outputFileDirectoryComboBox->setCurrentIndex(outputFileDirectoryComboBox->count() - 1);

inputFileNameComboBox->setCurrentIndex(inputFileNameComboBox->count() - 1);
 and
 outputFileDirectoryComboBox->setCurrentIndex(outputFileDirectoryComboBox->count() - 1);

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for other problem,try

out<<line<<'\r\n'

out<<line<<'\r\n'

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[HelloDan]

ok, regarding combobox problem, use

inputFileNameComboBox->setCurrentIndex(inputFileNameComboBox->count() - 1);
 and
 outputFileDirectoryComboBox->setCurrentIndex(outputFileDirectoryComboBox->count() - 1);

inputFileNameComboBox->setCurrentIndex(inputFileNameComboBox->count() - 1);
 and
 outputFileDirectoryComboBox->setCurrentIndex(outputFileDirectoryComboBox->count() - 1);

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for other problem,try

out<<line<<'\r\n'

out<<line<<'\r\n'

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Thanks! I had tried.

The drop down list one works well.

The output one in this way : out<<line<<"\r\n"; is more better.
In this way,the order is OK, but still miss the last part of the data.

[talk2amulya]

could you show the written file..i wanna see where it is missing..or u can use qDebug to print all lines that u r reading and showing...then show me the output

[HelloDan]

could you show the written file..i wanna see where it is missing..or u can use qDebug to print all lines that u r reading and showing...then show me the output

Thanks!
for example, the inputfile format is :
20040101 C 0 C 0 C 0 ENE 10 -1 11 0 0 -1 11 0 0
20040102 WSW 10 NW 30 NNW 30 NNW 10 -1 7 0 0 -1 6 0 0
20040103 NNW 20 C 0 SSE 20 SE 30 -1 8 0 0 -1 0 0 0
20040104 C 0 NE 10 S 20 SSW 10 -1 7 6 0 -1 0 0 0
20040105 E 10 C 0 S 20 C 0 -1 9 0 0 -1 0 0 0
20040106 E 10 NNW 20 SW 10 NNW 10 -1 10 6 0 -1 10 0 0


but the output one is only one line when the input data size is small.:
20040101 C 0 C 0 C 0 ENE 10 -1 11 0 0 -1 11 0 0


How to use a qDebug() in a GUI programming? I can make it in a console window, but fail in a GUI one. Maybe it's to fast, how I can make it pause? like system("pause");

Thanks!

[HelloDan]

while(file.pos()<file.size())  //-->
while(in.pos()<file.size())

while(file.pos()<file.size())  //-->
while(in.pos()<file.size())

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Somebody had helped me to solve the problem.


By the way, it's that any way to reuse output file name and QTextStream name? Such as:

if(month!=list.at(0))
{
QFile monthFile(outDirName+QDir::separator()+list.at(0)+".txt");
QTextStream monthOut(&monthFile);
month=list.at(0);
}
 
monthOut<<list.at(0)<<'\t'<<list.at(1)<<'\t'<<list.at(2)<<"\n";

if(month!=list.at(0))
{
QFile monthFile(outDirName+QDir::separator()+list.at(0)+".txt");
QTextStream monthOut(&monthFile);
month=list.at(0);
}

monthOut<<list.at(0)<<'\t'<<list.at(1)<<'\t'<<list.at(2)<<"\n";

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In my previous standard C++ code, I do it in this way:

while(getline(ifile, str))
{
filename = str.substr(0, 6)+".txt";
ofstream ofile(filename.c_str(), ios_base::app);
str.erase(0,10);
ofile << str << endl;
ofile.close();
}

while(getline(ifile, str))
{
filename = str.substr(0, 6)+".txt";
ofstream ofile(filename.c_str(), ios_base::app);
str.erase(0,10);
ofile << str << endl;
ofile.close();
}

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But I do think that reopen and reclose a file in this way is not a wise choice. But i can not work out a better method.

There are lots of problem to learn in practical experiment. Thanks sincerely to all the friends help me.