How to load a map in QT GUI application using text file

[SixDegrees]

Why isn't the std::ifstream approach working? Post your code and an explanation of the problem.

[jerkymotion]

I tried this on my GUI application ....Actually it should load the content of input.txt file in textedit when I clicked the button....but result does not come.ie the the text file is not loaded...and no errors are observed

void MainWindow::on_pushButton_clicked()
{
 
    QFile file("input.txt");
    file.open(QIODevice::ReadOnly);
    QTextStream in(&file);
    QString line;
 
       while (!in.atEnd())
    {
            line = in.readAll();
 
 
        ui->textEdit->setPlainText(line);
       }
      file.close();
 
}

void MainWindow::on_pushButton_clicked()
{
   
    QFile file("input.txt");
    file.open(QIODevice::ReadOnly);
    QTextStream in(&file);
    QString line;

       while (!in.atEnd())
    {
            line = in.readAll();

       
        ui->textEdit->setPlainText(line);
       }
      file.close();
 
}

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[wysota]

Why don't you check that the file actually gets opened?

[jerkymotion]

I again tried to display my text file in ...but now in textbrowser...this time my program ran succcessfully and I and i browsed to my text file and it did displayed the content of my textfile but..ERROR:nly single line is diplayed....please suggest me ...to improve my code

void MainWindow::on_pushButton_clicked()
{
    QString filename = QFileDialog::getOpenFileName(this, tr("wew"),"",tr("allfiles(*.txt)"));
    QFile file(filename);
    if(file.open(QIODevice::ReadOnly | QIODevice::Text));
    {
    QTextStream in(&file);
    QString line;
 
       while (!in.atEnd())
    {
            line = in.readLine();
 
        ui->textBrowser->setText(line);
        //ui->textEdit->setPlainText(line);
       }
 
      file.close();
  }
 
}

void MainWindow::on_pushButton_clicked()
{
    QString filename = QFileDialog::getOpenFileName(this, tr("wew"),"",tr("allfiles(*.txt)"));
    QFile file(filename);
    if(file.open(QIODevice::ReadOnly | QIODevice::Text));
    {
    QTextStream in(&file);
    QString line;

       while (!in.atEnd())
    {
            line = in.readLine();

        ui->textBrowser->setText(line);
        //ui->textEdit->setPlainText(line);
       }

      file.close();
  }

}

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[FelixB]

can you explain (in own words!) what happens in this snippet?

while (!in.atEnd())
{
  line = in.readLine();
  ui->textBrowser->setText(line);
}

while (!in.atEnd())
{
  line = in.readLine();
  ui->textBrowser->setText(line);
}

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[jerkymotion]

Ok I got it correct!!!
U don't know how to load a map using text file in qt creator

[wysota]

can anybody please help me to load map in qt creator

Sure. Launch QtCreator, from the "File" menu choose "Open file or project" and then browse until you see the file containing your map, select it and click on "Open". Your map should be opened in Qt Creator now.

[jerkymotion]

that's funny
actually I was asking about how to load a map using text file in qt creator????

[pan]

wysota might explode soon

jerkymotion, if you mean qt creator then he is right. If you mean Qt, then look at what felixB asked you and think about what you are doing there! It is the reason you are getting your result.

[FelixB]

why do you want to load such a map in Qt Creator?

[wysota]

that's funny
actually I was asking about how to load a map using text file in qt creator????

Is this your school project, a daily job project or a free-time project?

[jerkymotion]

Ok it's my school project
I wanted load a map for navigation purpose....so that if i clicked in the map it gives the co-ordinate value of that position and I want to send those value to my serial port...that's it
so I had an idea about loading a map via text file but I am finding it difficult in qt because I am newbie to Qt creator

[wysota]

Ok it's my school project

We have a rule on this forum that we can't give full solutions to school projects. We can only help you go in the right direction.

so I had an idea about loading a map via text file but I am finding it difficult in qt because I am newbie to Qt creator

Your approach with QFile looked correct but you dropped it for some reason. Maybe try going back to it and expand it. Think about an algorithm for reading the map. If necessary, take a piece of paper and a pencil and "emulate" the process or reading a file.