La lecture des fichiers PDF au format de la chaîne par le biais d'une application iPhone

Je suis confronté à un problème dans le développement d'une application iPhone pour la "Lecture PDF".
J'ai essayé le code suivant. Je sais que j'ai mal utilisé des méthodes d'analyse - analyse de méthodes sont utilisés uniquement pour la recherche de but. Mais je veux convertir fichier pdf entier de texte dans une chaîne de caractères. Disons, par exemple, Apple MobileHIG.pdf - j'ai utilisé dans le présent code.

@implementation NetPDFViewController
size_t totalPages;  //a variable to store total pages
//a method to get the pdf ref
CGPDFDocumentRef MyGetPDFDocumentRef (const char *filename) {
CFStringRef path;
CFURLRef url;
CGPDFDocumentRef document;
path = CFStringCreateWithCString (NULL, filename,kCFStringEncodingUTF8);
url = CFURLCreateWithFileSystemPath (NULL, path, kCFURLPOSIXPathStyle, 0);
CFRelease (path);
document = CGPDFDocumentCreateWithURL (url);//2
CFRelease(url);
int count = CGPDFDocumentGetNumberOfPages (document);//3
if (count == 0) {
printf("`%s' needs at least one page!", filename);
return NULL;
}
return document;
}
//table methods to parse pdf
static void op_MP (CGPDFScannerRef s, void *info) {
const char *name;
if (!CGPDFScannerPopName(s, &name))
return;
printf("MP /%s\n", name);   
}
static void op_DP (CGPDFScannerRef s, void *info) {
const char *name;
if (!CGPDFScannerPopName(s, &name))
return;
printf("DP /%s\n", name);   
}
static void op_BMC (CGPDFScannerRef s, void *info) {
const char *name;
if (!CGPDFScannerPopName(s, &name))
return;
printf("BMC /%s\n", name);  
}
static void op_BDC (CGPDFScannerRef s, void *info) {
const char *name;
if (!CGPDFScannerPopName(s, &name))
return;
printf("BDC /%s\n", name);  
}
static void op_EMC (CGPDFScannerRef s, void *info) {
const char *name;
if (!CGPDFScannerPopName(s, &name))
return;
printf("EMC /%s\n", name);  
}
//a method to display pdf page.
void MyDisplayPDFPage (CGContextRef myContext,size_t pageNumber,const char *filename) {
CGPDFDocumentRef document;
CGPDFPageRef page;
document = MyGetPDFDocumentRef (filename);//1
totalPages=CGPDFDocumentGetNumberOfPages(document);
page = CGPDFDocumentGetPage (document, pageNumber);//2
CGPDFDictionaryRef d;
d = CGPDFPageGetDictionary(page);
//----- edit   problem here - CGPDFDictionary is completely unknown 
//----- as we don't know keys & values of it.
CGPDFScannerRef myScanner; 
CGPDFOperatorTableRef myTable;
myTable = CGPDFOperatorTableCreate();
CGPDFOperatorTableSetCallback (myTable, "MP", &op_MP);
CGPDFOperatorTableSetCallback (myTable, "DP", &op_DP);
CGPDFOperatorTableSetCallback (myTable, "BMC", &op_BMC);
CGPDFOperatorTableSetCallback (myTable, "BDC", &op_BDC);
CGPDFOperatorTableSetCallback (myTable, "EMC", &op_EMC);
CGPDFContentStreamRef myContentStream = CGPDFContentStreamCreateWithPage (page);//3
myScanner = CGPDFScannerCreate (myContentStream, myTable, NULL);//4
CGPDFScannerScan (myScanner);//5
// CGPDFDictionaryRef d;
CGPDFStringRef str; //represents a sequence of bytes
d = CGPDFPageGetDictionary(page);
if (CGPDFDictionaryGetString(d, "Thumb", &str)){
CFStringRef s;
s = CGPDFStringCopyTextString(str);
if (s != NULL) {
//need something in here in case it cant find anything
NSLog(@"%@ testing it", s);
}
CFRelease(s);       
//     CFDataRef data = CGPDFStreamCopyData (stream, CGPDFDataFormatRaw);
}
//-----------------------------------  
CGContextDrawPDFPage (myContext, page);//3
CGContextTranslateCTM(myContext, 0, 20);
CGContextScaleCTM(myContext, 1.0, -1.0);
CGPDFDocumentRelease (document);//4
}
- (void)viewDidLoad {
[super viewDidLoad];
//-------------------------------------------------------- 
//code for simple direct image from pdf docs.
UIGraphicsBeginImageContext(CGSizeMake(320, 460));
initialPage=28;
MyDisplayPDFPage(UIGraphicsGetCurrentContext(), initialPage, [[[NSBundle mainBundle] pathForResource:@"MobileHIG" ofType:@"pdf"] UTF8String]);
imgV.image=UIGraphicsGetImageFromCurrentImageContext();
imgV.image=[imgV.image rotate:UIImageOrientationDownMirrored];  
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
CGPoint LasttouchPoint =  [touch locationInView:self.view];
int LasttouchX = LasttouchPoint.x;
startpoint=LasttouchX;
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
CGPoint LasttouchPoint =  [touch locationInView:self.view];
int LasttouchX = LasttouchPoint.x;
endpoint=LasttouchX;
if(startpoint>(endpoint+75)){
initialPage++;
[self loadPage:initialPage nextOne:YES];
} else if((startpoint+75)<endpoint){
initialPage--;
[self loadPage:initialPage nextOne:NO];
}
}
-(void)loadPage:(NSUInteger)page nextOne:(BOOL)yesOrNo{
if(page<=totalPages && page>0){
UIGraphicsBeginImageContext(CGSizeMake(720, 720));  
MyDisplayPDFPage(UIGraphicsGetCurrentContext(), page, [[[NSBundle mainBundle] pathForResource:@"MobileHIG" ofType:@"pdf"] UTF8String]);
CATransition *transition = [CATransition animation];
transition.duration = 0.75;
transition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
transition.type=kCATransitionPush;
if(yesOrNo){
transition.subtype=kCATransitionFromRight;
} else {
transition.subtype=kCATransitionFromLeft;
}
transition.delegate = self;
[imgV.layer addAnimation:transition forKey:nil];
imgV.image=UIGraphicsGetImageFromCurrentImageContext();
imgV.image=[imgV.image rotate:UIImageOrientationDownMirrored];
}
}

Mais je n'ai pas eu de succès à même de lire une seule ligne dans le document pdf.
Ce qui manque encore?