CODEWITHSUNDEEP
c++qtline
Anastazja Frontczak
Anastazja Frontczak

Reputation: 11

How do I read specific lines from a txt file- Qt?

I am making a program that reads a txt file. I want to read some specific lines from a file and add them to ComboBox. (in my case would be line number: 1,6,11,16...)

I have only this that reads all the lines.

 if(file.open (QIODevice::ReadOnly | QIODevice::Text))
{
    while(!stream.atEnd())
    {
        line = stream.readLine ();
        if(!line.isNull ())
        {
            ui->ServersNames->addItem (line);
        }
     }
 }
    stream.flush ();
    file.close ();

Upvotes: 0

Views: 1348

Answers (1)

Fareanor
Fareanor

Reputation: 6805

According to me, you cannot go to a specific line without knowing the line(s) size(s) since seek() can only move the cursor into a specific position value.

The only solution I can see is the one suggested by @Botje.

Based on your code, you could write:

if(file.open(QIODevice::ReadOnly | QIODevice::Text))
{
    int nb_line(0);
    while(!stream.atEnd())
    {
        line = stream.readLine();
        if((nb_line % 5) == 1)
            ui->ServersNames->addItem(line);
        ++nb_line;
    }
    file.close();
}

Of course, it assumes that you want to read one in five lines from the first line until the end of the file.

Upvotes: 2

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