A literal is a string written in code with "quotes around it". A literal is not a wxString, and (in wxWidgets 2.8) will not be implicitly converted to one. This means that you can never pass in a raw literal into a wxWidget function or method (unless you don't care about your app not building with Unicode-enabled wxWidgets builds)
MessageBox("I'm a mistake!") // WRONG in WxWidgets 2.8 (OK in 2.9)
Instead, wxWidgets (prior to wxWidgets 2.9) requires you to use one of these macros to turn literals into wxString-compatible characters:
_("text that can be translated") wxT("text that won't be translated") _T("same as wxT") char* c = "sometext"; wxT(c) // WRONG, not a literal
Rather than being a nuisance, the _(), wxT(), and _T() macros take care of some unicode issues and help with internationalization.
Note that in wxWidgets 2.9, it just works to pass a char array where a wxString parameter is expected, the conversion will be automatic and implicit, using the current locale encoding. So even in wx 2.9, the snippets presented below still make sense when you don't want to be at the mercy of the current locale encoding.
const char* chars = "Hello world"; // if your string is UTF-8 encoded, this is the shortest path : wxString mystring = wxString::FromUTF8(chars); // You can also convert from many encodings by passing the // appropriate wxConv... parameter to the constructor wxString mystring2(chars, wxConvUTF8);
void my_function(const char* foo) { } ... wxString mystring(wxT("HelloWorld")); // you could give the encoding you want as a parameter to mb_str(), e.g. mb_str(wxConvUTF8) my_function( mystring.mb_str() );
mb_str() returns a temporary pointer; if you need the output for more than one function call (as is the case above), you can store the char buffer for a little while :
wxString s( wxT("some string") ); wxCharBuffer buffer=s.ToUTF8(); foo( buffer.data() ); // data() returns const char * bar( buffer.data(), strlen(buffer.data()) ); // in case you need the length of the data
And if you really need to copy it in to char* (but why would you? ;) :
wxString mystring(wxT("HelloWorld")); char cstring[1024]; // assuming you want UTF-8, change the wxConv* parameter as needed strncpy(cstring, (const char*)mystring.mb_str(wxConvUTF8), 1023);
You can also use ToUTF8(), since which encoding you get is clearer than with mb_str()
From const char* to char*:
Variadic functions (like printf) won't work with mb_str(), but this will work:
Alternatively, use the method recommended in Potential Unicode Pitfalls:
printf("%s", (const char*)mystring.mb_str())
const wchar_t* chars = L"Hello world"; wxString mystring(chars);
See the following methods in the docs :
TCHAR tCharString[255]; wxString myString(_T("Hello World")); const wxChar* myStringChars = myString.c_str(); for (int i = 0; i < myString.Len(); i++) { tCharString[i] = myStringChars [i]; } tCharString[myString.Len()] = _T('\0');
or
wxString mystring; mystring << myint;
or
wxString mystring; mystring << myfloat;
or
std::string stlstring = "Hello world"; // assuming your string is encoded as UTF-8, change the wxConv* parameter as needed wxString mystring(stlstring.c_str(), wxConvUTF8);
Starting from wxWidgets 2.9, you may also use the appropriate constructor
std::string stlstring = "Hello world"; // assuming your string is encoded as the current locale encoding (wxConvLibc) wxString mystring(stlstring);
wxWidgets 2.8 :
Under wxWidgets 2.9, you may use
wxString::ToStdString()
Starting from wxWidgets 2.9, you may use the appropriate constructor
std::sstring stlstring = L"Hello world"; // assuming your string is encoded as the current locale encoding (wxConvLibc) wxString mystring(stlstring);
Under wxWidgets 2.9, you may use
wxString::ToStdWstring()