Converting everything to and from wxString
This question seems common so I thought I'd write an article. Note that sometimes there may be more than one possible solutions, so don't forget to check the docs.
Note that it is recommended to use wxString as much as possible. Do no use char* or std::string unless you use a third-party library that requires you to do so.
Literals
A literal is a string written in code with "quotes around it". A literal is not a wxString, and will not be implicitly converted to one. This means that you can never pass in a raw literal into a wxWidget function or method.
MessageBox("I'm a mistake!") // WRONG
Instead, Unicode builds (prior to wxWidgets 2.9) require you to use one of these macros to turn literals into wxString-compatible characters:
_("text that can be translated")
wxT("text that can'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.
char* to wxString
char* chars = "Hello world";
wxString mystring(chars, wxConvUTF8);
wxString to char*
void my_function(const char* foo)
{
}
...
wxString mystring(wxT("HelloWorld"));
my_function( mystring.mb_str() );
mb_str() returns a temporary pointer. If you need to store it in a char* :
wxString mystring(wxT("HelloWorld"));
char cstring[1024];
strcpy(cstring, (const char*)mystring.mb_str(wxConvUTF8));
You can also use ToUTF8(), since which encoding you get is clearer than with mb_str()
wxString to TCHAR
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');
int to wxString
wxString mystring = wxString::Format(wxT("%i"),myint);
or
wxString mystring;
mystring << myint;
float to wxString
wxString mystring = wxString::Format(wxT("%f"), myfloat);
or
wxString mystring;
mystring << myfloat;
wxString to integer number
wxString number(wxT("145"));
long value;
if(!number.ToLong(&value)) { /* error! */ }
or
wxString str = _T("123");
int num;
num = wxAtoi(str);
wxString to floating-point number
wxString number(wxT("3.14159"));
double value;
if(!number.ToDouble(&value)){ /* error! */ }
std::string to wxString
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);
wxString to std::string
wxString mystring(wxT("HelloWorld"));
std::string stlstring = std::string(mystring.mb_str());