iOS开发笔记——PDF的显示和浏览

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iOS开发笔记——PDF的显示和浏览

作者：yiyaaixuexi，发布于2012-10-9,来源：新浪博客

今天的任务是：在iOS上加载显示pdf文件。

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];   
}