How to change string into QString

Question

What is the most basic way to do it

User · Answer

If compiled with STL compatibility  QString has a static method to convert a std  string to a QString   std  string str    abc   QString qstr   QString  fromStdString str

User · Answer

Alternative way   std  string s    This is an STL string   QString qs   QString  fromAscii s data    s size       This has the advantage of not using  c str   which might cause the std  string to copy itself in case there is no place to add the   0  at the end

User · Answer

std  string s    Sambuca   QString q   s c str      Warning  This won t work if the std  string contains  0s

User · Answer

I came across this question because I had a problem when following the answers  so I post my solution here   The above examples all show samples with strings containing only ASCII values  in which case everything works fine  However  when dealing with strings in Windows whcih can also contain other characters  like german umlauts  then these solutions don t work  The only code that gives correct results in such cases is  std  string s      bernahme   QString q   QString  fromLocal8Bit s c str       If you don t have to deal with such strings  then the above answers will work fine

User · Answer

Moreover  to convert whatever you want  you can use the QVariant class   for example    std  string str  hello      qDebug    lt  lt  QVariant str c str    toString    int test   10  double titi   5 42  qDebug    lt  lt  QVariant test  toString    qDebug    lt  lt  QVariant titi  toString    qDebug    lt  lt  QVariant titi  toInt      output   hello     10   5 42  5

User · Answer

Do you mean a C string  as in a char  string  or a C   std  string object   Either way  you use the same constructor  as documented in the QT reference    Qt QString Reference   For a regular C string  just use the main constructor   char name      Stack Overflow   QString qname name     For a std  string  you obtain the char  to the buffer and pass that to the QString constructor   std  string name2  Stack Overflow    QString qname2 name2 c str

User · Answer

If by string you mean std  string you can do it with this method   QString QString  fromStdString const std  string  amp  str   std  string str    Hello world   QString qstr   QString  fromStdString str       If by string you mean Ascii encoded const char   then you can use this method   QString QString  fromAscii const char   str  int size   -1   const char  str    Hello world   QString qstr   QString  fromAscii str       If you have const char   encoded with system encoding that can be read with QTextCodec  codecForLocale   then you should use this method   QString QString  fromLocal8Bit const char   str  int size   -1   const char  str    zaz  lc gesla jazn           latin2 source file and system encoding QString qstr   QString  fromLocal8Bit str       If you have const char   that s UTF8 encoded then you ll need to use this method   QString QString  fromUtf8 const char   str  int size   -1   const char  str   read raw  hello txt       assuming hello txt is UTF8 encoded  and read raw   reads bytes from file into memory and returns pointer to the first byte as const char  QString qstr   QString  fromUtf8 str       There s also method for const ushort   containing UTF16 encoded string   QString QString  fromUtf16 const ushort   unicode  int size   -1   const ushort  str   read raw  hello txt       assuming hello txt is UTF16 encoded  and read raw   reads bytes from file into memory and returns pointer to the first byte as const ushort  QString qstr   QString  fromUtf16 str

[c++] How to change string into QString?

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