Webutil_c_api char error

Question

I'm trying to execute the following C function:
extern "C" PRUEBADLL_API int fnPruebaDLL(char* value);
This function shows a simple Dialog.
Firtsly I executed the function:
extern "C" PRUEBADLL_API int fnPruebaDLL();
And it was ok. But with the param it doesn't work. My PL/SQL code is:
          FUNCTION dll_PruebaDLL(value1 IN OUT CHAR) RETURN PLS_INTEGER IS
               prueba_func webutil_c_api.FunctionHandle;
               prueba_params webutil_c_api.ParameterList;
               prueba_param1 webutil_c_api.ParameterHandle;
               prueba_return PLS_INTEGER;
               BEGIN
                    prueba_func := webutil_c_api.register_function('PruebaDLL.dll', 'fnPruebaDLL');
                    prueba_params := webutil_c_api.create_parameter_list;
                    prueba_param1 := webutil_c_api.add_parameter(prueba_params, webutil_c_api.C_CHAR_PTR, webutil_c_api.PARAM_INOUT, value1);
                    prueba_return := webutil_c_api.Invoke_Int('PruebaDLL.dll', 'fnPruebaDLL', prueba_params);
                    webutil_c_api.destroy_parameter_list(prueba_params);
                    webutil_c_api.deregister_function(prueba_func);
                    return prueba_return;          
          END dll_PruebaDLL;           
Does anybody know why it doesn't work?

Answer 1

You ommit the length of value1.
This line
prueba_param1 := webutil_c_api.add_parameter(prueba_params, webutil_c_api.C_CHAR_PTR, webutil_c_api.PARAM_INOUT, value1);
should read
prueba_param1 := webutil_c_api.add_parameter(prueba_params, webutil_c_api.C_CHAR_PTR, webutil_c_api.PARAM_INOUT, value1, length(value1));