Using a QProgressbar in a For Loop

[kiboi]

Hi! I want to use a Qprogressbar using a For Loop. Every time the value inside the for loop changes, it sets the value of the progress bar. A sample code will be helpful.


Thanks!

[wysota]

for(int i=0;i<100;++i) { progressBar->setValue(i); qApp->processEvents(); }

for(int i=0;i<100;++i) { progressBar->setValue(i); qApp->processEvents(); }

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[kiboi]

thanks wysota. regarding process events, i tried it now, but it seems the process becomes slow. is there a way to adjust the process time? the process im doing is transferring of files.
Thanks!

[wysota]

thanks wysota. regarding process events, i tried it now, but it seems the process becomes slow.

Obviously as your application has much more to do.

is there a way to adjust the process time? the process im doing is transferring of files.

e.g.

for(int i=0;i<100;++i) { progressBar->setValue(i); if(i % 100 == 0) qApp->processEvents(); }

for(int i=0;i<100;++i) { progressBar->setValue(i); if(i % 100 == 0) qApp->processEvents(); }

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[kiboi]

my concern is that i want to prevent the application to get into "not responding" status if seen at the task manager while doing the for loop. i'll try your suggestion.thanks!

[wysota]

You can always copy files in a secondary thread, e.g. something like this might work:

struct FileStruct {
  QString sourcePath;
  QString destPath;
  FileStruct(s, d) : sourcePath(s), destPath(d) {}
};
 
bool copyFile(FileStruct s) {
  QFile::copy(s.sourcePath, s.destPath);
  return true;
}
 
QList<FileStruct> filesToCopy;
filesToCopy << FileStruct(...,...) << FileStruct(...,...) << FileStruct(...,...);
 
QFuture<bool> result = QtConcurrent::mapped(filesToCopy, copyFile);

struct FileStruct {
  QString sourcePath;
  QString destPath;
  FileStruct(s, d) : sourcePath(s), destPath(d) {}
};

bool copyFile(FileStruct s) {
  QFile::copy(s.sourcePath, s.destPath);
  return true;
}

QList<FileStruct> filesToCopy;
filesToCopy << FileStruct(...,...) << FileStruct(...,...) << FileStruct(...,...);

QFuture<bool> result = QtConcurrent::mapped(filesToCopy, copyFile);

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but it will probably be slower than copying one file at a time (unless you have a SSD disk).