im using QTextStreamer to read a QFile using
if(file.open(QIODevice::ReadOnly | QIODevice::Text))
{
QTextStream stream(&file);
line = stream.readLine();
//...
but in my requirement i need only to read particular set of lines only from my file. ex: if the file contains 1034 lines. user can select only from line 107 to 300 line to be read and display in a textBox.
how can i adjust the position of the qtextStream reader to point on the particular line of the file.
right now im implementing as
int count = 4;
while(count > 0)
{
line = stream.readLine();
count--;
}
line = stream.readLine();
QTextStream is a stream, not array. That because you can't get some line without read it.
Some way is (just a simplest example):
QFile file("file_name");
QTextStream stream(&file);
QStringList list;
int line = 0;
if(file.open(QIODevice::ReadOnly))
while(!stream.atEnd()) {
if(line == 4 || line == 5 || line == 6)
list << stream.readLine();
else
stream.readLine();
line++;
}
The harder way:
if(file.open(QIODevice::ReadOnly)) {
QByteArray ar = file.readAll();
QByteArray str;
for(int i = 0; i < ar.size(); i++) {
if(line == 4 || line == 5 || line == 6) {
if(ar.at(i) == '\n') {
list << QString::fromUtf8(str.replace("\r", ""));
str.clear();
}
else
str += ar.at(i);
}
if(ar.at(i) == '\n')
line++;
}
}