Qt没有直接的接口去获取到当前系统用户名，只能够间接的通过现有的接口去获取。（比如下边的例子通过获取home路径）

c++	//Qt4 version
	QString getUserName() 
	{
		QString userName = QDesktopServices::storageLocation(QDesktopServices::HomeLocation);
		userName = userName.section("/", -1, -1); 
		return userName; 
   }
  
  //Qt5 version
  
	QString getUserName()
	{
		QString userPath = QStandardPaths::writableLocation(QStandardPaths::HomeLocation); 
		QString userName = userPath.section("/", -1, -1); 
		return userName; 
	}