iOS pdf的显示和浏览

方法一：利用webview

 -(void)loadDocument:(NSString *)documentName inView:(UIWebView *)webView
 {
     NSString *path = [[NSBundle mainBundle] pathForResource:documentName ofType:nil];
     NSURL *url = [NSURL fileURLWithPath:path];
     NSURLRequest *request = [NSURLRequest requestWithURL:url];
     [webView loadRequest:request];
 }

利：1.实现简单

        2.还是实现简单

弊：1.仅能浏览，拿不到任何回调，safari不会鸟任何人。

        2.固定竖版拖动，想实现翻页动效果就扒瞎

        

        下面的方法可以解决webview 显示pdf的弊，相对的，要付出一些汗水作为代价了。

方法二：利用CGContextDrawPDFPage

 CGPDFDocumentRef GetPDFDocumentRef(NSString *filename)
 {
     CFStringRef path;
     CFURLRef url;
     CGPDFDocumentRef document;
     size_t count;

     path = CFStringCreateWithCString (NULL, [filename UTF8String], kCFStringEncodingUTF8);
     url = CFURLCreateWithFileSystemPath (NULL, path, kCFURLPOSIXPathStyle, 0);

     CFRelease (path);
     document = CGPDFDocumentCreateWithURL (url);
     CFRelease(url);
     count = CGPDFDocumentGetNumberOfPages (document);
     if (count == 0) {
         printf("[%s] needs at least one page!\n", [filename UTF8String]);
         return NULL;
     } else {
         printf("[%ld] pages loaded in this PDF!\n", count);
     }
     return document;
 }

 void DisplayPDFPage (CGContextRef myContext, size_t pageNumber, NSString *filename)
 {
     CGPDFDocumentRef document;
     CGPDFPageRef page;

     document = GetPDFDocumentRef (filename);
     page = CGPDFDocumentGetPage (document, pageNumber);
     CGContextDrawPDFPage (myContext, page);
     CGPDFDocumentRelease (document);
 }

这样显示出来的pdf单页是倒立的，Quartz坐标系和UIView坐标系不一样所致，调整坐标系，使pdf正立：

 CGContextRef context = UIGraphicsGetCurrentContext();
 CGContextTranslateCTM(context, 80, self.frame.size.height-60);
 CGContextScaleCTM(context, 1, -1);

配合iOS5强大的UIPageViewController实现翻页浏览

 - (PDFViewController *)viewControllerAtIndex:(NSUInteger)index
 {
     //Return the PDFViewController for the given index.
     if (([self.pagePDF count] == 0 )|| (index > [self.pagePDF count]) ) {
         return nil;
     }

     //Create a new view controller and pass suitable data.
     PDFViewController *dataViewController = [[PDFViewController alloc]initWithNibName:@"PDFViewController" bundle:nil];
     //dataViewController.pdfview = [self.pagePDF objectAtIndex:index];
     dataViewController.pdfview = [[PDFView alloc]initWithFrame:self.view.frame atPage:index];
     [dataViewController.view addSubview:dataViewController.pdfview];
     NSLog(@"index = %d",index);
     return dataViewController;
 }

 - (NSUInteger) indexOfViewController:(PDFViewController *)viewController
 {
     return [self.pagePDF indexOfObject:viewController.pdfview];
 }

 - (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController
 {
     NSUInteger index = [self indexOfViewController:(PDFViewController *)viewController];
     if ((index == 0 ) || (index == NSNotFound)){
         return nil;
     }

     index--;
     return  [self viewControllerAtIndex:index];
 }

 - (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController
 {
     NSUInteger index = [self indexOfViewController:(PDFViewController *)viewController];
     if (index == NSNotFound)
     {
         return nil;
     }

     index++;

     if (index == [self.pagePDF count]){
         return  nil;
     }

     return [self viewControllerAtIndex:index];
 }