Qstring和String的区别

QString qTest;
std::string sTest = qTest.toStdString();
qTest = QString::fromStdString(sTest);

//进入两个函数源码
inline std::string QString::toStdString() const
{ return toUtf8().toStdString(); }//string是UTF8

inline QString QString::fromStdString(const std::string &s)
{ return fromUtf8(s.data(), int(s.size())); }