Solution 1:

You can use this QString constructor for conversion from QByteArray to QString:

QString(const QByteArray &ba)

QByteArray data;
QString DataAsString = QString(data);

Solution 2:

You can use QTextCodec to convert the bytearray to a string:

QString DataAsString = QTextCodec::codecForMib(1015)->toUnicode(Data);

(1015 is UTF-16, 1014 UTF-16LE, 1013 UTF-16BE, 106 UTF-8)

From your example we can see that the string "test" is encoded as "t\0 e\0 s\0 t\0 \0 \0" in your encoding, i.e. every ascii character is followed by a \0-byte, or resp. every ascii character is encoded as 2 bytes. The only unicode encoding in which ascii letters are encoded in this way, are UTF-16 or UCS-2 (which is a restricted version of UTF-16), so in your case the 1015 mib is needed (assuming your local endianess is the same as the input endianess).