error: Implicit conversion of C pointer type...

Yes

#import <UIKit/UIKit.h>
#import "PDFIOS.h"
#import "PDFView.h"
#import <CoreData/CoreData.h>
@class PDFV;
@class PDFView;

@interface RDPDFViewController : UIViewController {

PDFView *m_view;
PDF_DOC *m_doc;
}
- (int)PDFOpen:(NSString *)path withPassword:(NSString *)pwd;
- (void)PDFClose;

@end

Emm. m_doc should define as PDFDoc . You can see RDPDFViewController.h

PDFView *m_view;
PDFVThumb *m_Thumbview;
PDFDoc *m_doc;

emm..i do copy and paste from ios_help. please correct it.
Thanks for helping me.

:ohmy: Thank you for this .We'll updated it.