Conversion of QString unsigned char*

QString-Unsigned char*:
      QString  str = "ABCD";
     int length = Str.length ();
      unsigned char* sequence = NULL;
sequence = (unsigned char*) qstrdup (Str.toascii (). Constdata ());
      Delete[] sequence;
      -Sequence length = 5--[' A '] [' B '] [' C '] [' D '] ['/0 ']
      -Sequence is now ' independant ' from str
      -Sequence have to is deleted with--delete [] sequence
QString-Char:
      Const Qbytearray BA = String.toascii (); Make BA const, because modifying this array might otherwise invalidate the pointer
  Const char* sequence = Ba.constdata (); Now sequence'll remain valid within the current scope.    
  

  
    Char *sequence = String.toascii (). Constdata ();
    Sequence is now a dangling pointer!

http://wxpjiujiang.blog.163.com/blog/static/203994030201292661134137/

Conversion of QString unsigned char*