iOS開發筆記——PDF的顯示和瀏覽

       今天的任務是：在iOS上載入顯示pdf檔案。

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.實現簡單

        2.還是實現簡單

弊：1.僅能瀏覽，拿不到任何回調，safari不會鳥任何人。

        2.固定豎版拖動，想實現翻頁動效果就扒瞎

        

        下面的方法可以解決webview 顯示pdf的弊，相對的，要付出一些汗水作為代價了。

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);}

這樣顯示出來的pdf單頁是倒立的，Quartz座標系和UIView座標系不一樣所致，調整座標系，使pdf正立：

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

配合iOS5強大的UIPageViewController實現翻頁瀏覽

- (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];}

後續將完成塗鴉pdf後儲存建立新pdf的功能。

特別感謝cclv的協助和指點。