Question

Im new in MonoTouch. I am currently trying to bind an Objective-C library into MonoTouch, so far I’ve done much of the work, however, i don’t know how to bind the following code :

static inline NSString* UmRet_lookup(UmRet c) {
#define URLOOK(a) case a: return @#a;
switch (c) {
    URLOOK(UMRET_SUCCESS          )
    URLOOK(UMRET_NO_READER        )
    URLOOK(UMRET_SDK_BUSY         )
    URLOOK(UMRET_ALREADY_CONNECTED)
    URLOOK(UMRET_NOT_CONNECTED    )
    URLOOK(UMRET_LOW_VOLUME       )
    URLOOK(UMRET_UF_INVALID_STR   )
    URLOOK(UMRET_UF_NO_FILE       )
    URLOOK(UMRET_UF_INVALID_FILE  )
    default: return @"<unknown code>";
    }
    #undef URLOOK
}

And also the next code :

#define UMLOG_ERROR    @"[UM Error] "
#define UMLOG_WARNING  @"[UM Warning] "
#define UMLOG_INFO     @"[UM Info] "

Answer 1

You cannot bind this as it’s not really Objective-C code but some C pre-processor directives.

In such cases you need to rewrite this into C#. This looks to be some translation of error codes into string representation. Depending on your app you might want to use C# strings (instead of NSString).

static public NSString UmRet_lookup (UmRet c)
{
   switch (c) {
   case UMRET_SUCCESS : return new NSString ("UMRET_SUCCESS");
   case UMRET_NO_READER : return new NSString ("UMRET_NO_READER");
   case UMRET_SDK_BUSY : return new NSString ("UMRET_SDK_BUSY");
   case UMRET_ALREADY_CONNECTED : return new NSString ("UMRET_ALREADY_CONNECTED");
   case UMRET_NOT_CONNECTED : return new NSString ("UMRET_NOT_CONNECTED");
   case UMRET_LOW_VOLUME : return new NSString ("UMRET_LOW_VOLUME");
   case UMRET_UF_INVALID_STR : return new NSString ("UMRET_UF_INVALID_STR");
   case UMRET_UF_NO_FILE : return new NSString ("UMRET_UF_NO_FILE");
   case UMRET_UF_INVALID_FILE : return new NSString ("UMRET_UF_INVALID_FILE");
   default: return new NSString ("<unknown code>");
   }
}

The other defines should be converted into C# static, e.g.

static public NSString UMLOG_ERROR = new NSString ("[UM Error] ");
static public NSString UMLOG_WARNING = new NSString ("[UM Warning] ");
static public NSString UMLOG_INFO = new NSString ("[UM Info] ");

Again you might want to use C# string (and turn them into const too).