QTextCodec::setCodecForCStrings('UTF-8') can then be used to make Qt interpret all the char* pointers correctly as UTF-8.Įven though QTextCodec::setCodecForCStrings() is a nice convenience, it is recommended to use only ASCII characters in source files. Such source files are saved as UTF-8 and the exec charset of the compiler is set to UTF-8. A common case this occurs is when source files contain non-ASCII characters. The only reason to use QTextCodec::setCodecForCStrings is when the exec charset is not ASCII. Calling this function makes QString::fromAscii() decode C-style strings using the new charset (in other words, it doesn't decode ASCII anymore). QTextCodec::setCodecForCStrings(exec-charset) can be used to change the encoding that Qt uses to decode C-style strings. It is thus possible to get away with placing Latin-1 characters in C-strings. QString::fromAscii(), in turn, attempts to decode the characters as Latin-1 (since Ascii and Latin-1 are compatible). Internally, this conversion uses the same code path as QString::fromAscii(). By default, Qt assumes that this is ASCII. At run time, QString gets a pointer to this memory location and needs to interpret and convert the bytes to unicode.įor converting the C-style string to Unicode, QString needs to know the exec charset. The compiler generates code that puts the C-style string 'Qt' in memory with possibly some other encoding called the exec charset. The above code is saved in some file with encoding called the the input charset.

One main reason to use UTF-16 as the internal representation is that it makes it fast to use them with native unicode APIs' on the Mac OS X and Windows (which expect UTF-16).įor processing a C-style char-pointer or an array of bytes, QByteArray should be used instead of QString. Each of the 2 bytes of UTF-16 is represented using a QChar. Internally, QString stores the string using the UTF-16 encoding. All user-visible strings in Qt are stored in QString. A QString can be rendered on the screen or to a printer, provided there is a font to display the characters that the QString holds. This is in contrast to a C-style string (char*) that has no knowledge of encoding by itself. By definition, since QString stores unicode, a QString knows what characters it's contents represent. The fundamentals of encoding are covered in Basics of String Encoding. Written by Girish Ramakrishnan, ForwardBias Technologies En Ar Bg De El Es Fa Fi Fr Hi Hu It Ja Kn Ko Ms Nl Pl Pt Ru Sq Th Tr Uk Zh

Qstring startswith ida