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Qt Code: 
  1. #include <QtCore>
  2. #include <QDebug>
  3.  
  4. int main(int argc, char *argv[]) 
  5. {
  6.     QCoreApplication app(argc, argv);
  7.  
  8.     QFile in("C:/windows/system32/user32.dll");
  9.     QFile out(QDir::tempPath() + "/user32.dll");
  10.     if (in.open(QIODevice::ReadOnly)) {
  11.         if (out.open(QIODevice::WriteOnly)) {
  12.             QByteArray data = in.readAll();
  13.             qint64 written = out.write(data);
  14.             qDebug() << "Read:" << in.size() << "Wrote:" << written;
  15.             out.close();
  16.         }
  17.         else {
  18.             qDebug() << "Cannot open output file" << out.errorString();
  19.         }
  20.     }
  21.     else {
  22.         qDebug() << "Cannot open input file" << in.errorString();
  23.     }
  24.     return 0;
  25. }
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