qt qstring-為什麼QT需要封裝QString，而不需要封裝 int double ？？？？ 真心求解

為什麼QT需要封裝QString，而不需要封裝 int double ？？？？ 真心求解

做了一些QT的小項目，自己也寫了 QStingtoStr的一些轉換函數，可是不懂QT為什麼非要把string給封裝了，又不提供轉換的函數。

最佳回答：

下面這些還不夠嗎，還要自己寫轉換方法？
std::string QString::toStdString () const
Returns a std::string object with the data contained in this QString. The Unicode data is converted into 8-bit characters using the toAscii() function.

This operator is mostly useful to pass a QString to a function that accepts a std::string object.

If the QString contains Unicode characters that the QTextCodec::codecForCStrings() codec cannot handle, using this operator can lead to loss of information.

This operator is only available if Qt is configured with STL compatibility enabled.

See also toAscii(), toLatin1(), toUtf8(), and toLocal8Bit().