使用Quartz在iOS上获取PDF超链接

Question

我花了一整天时间尝试从我的iPad应用程序中获取PDF中的超链接元数据。 CGPDF * API是一个真正的噩梦，我在网上发现的关于这一切的唯一信息是我必须寻找一个“Annots”字典，但我在我的PDF中找不到它。

我甚至使用旧Voyeur Xcode sample来检查我的测试PDF文件，但没有这个“Annots”字典的痕迹......

你知道，这是我在每个PDF阅读器上看到的一个功能 - 同样的问题在been asked multiple times这里没有真正的实际答案。我通常不会直接询问示例代码，但显然这次我真的需要它......任何人都有这个工作，可能带有示例代码？

更新：我刚刚意识到已完成测试PDF的人刚刚插入了一个URL作为文本，而不是真正的注释。他尝试使用注释，我的代码现在正常工作......但这不是我需要的，所以我似乎必须分析文本并搜索URL。但那是另一个故事......

更新2 ：所以我终于提出了一些有效的代码。我在这里张贴它，所以希望它能帮助别人。它假定PDF文档实际上包含注释。

for(int i=0; i<pageCount; i++) {
    CGPDFPageRef page = CGPDFDocumentGetPage(doc, i+1);

    CGPDFDictionaryRef pageDictionary = CGPDFPageGetDictionary(page);

    CGPDFArrayRef outputArray;
    if(!CGPDFDictionaryGetArray(pageDictionary, "Annots", &outputArray)) {
        return;
    }

    int arrayCount = CGPDFArrayGetCount( outputArray );
    if(!arrayCount) {
        continue;
    }

    for( int j = 0; j < arrayCount; ++j ) {
        CGPDFObjectRef aDictObj;
        if(!CGPDFArrayGetObject(outputArray, j, &aDictObj)) {
            return;
        }

        CGPDFDictionaryRef annotDict;
        if(!CGPDFObjectGetValue(aDictObj, kCGPDFObjectTypeDictionary, &annotDict)) {
            return;
        }

        CGPDFDictionaryRef aDict;
        if(!CGPDFDictionaryGetDictionary(annotDict, "A", &aDict)) {
            return;
        }

        CGPDFStringRef uriStringRef;
        if(!CGPDFDictionaryGetString(aDict, "URI", &uriStringRef)) {
            return;
        }

        CGPDFArrayRef rectArray;
        if(!CGPDFDictionaryGetArray(annotDict, "Rect", &rectArray)) {
            return;
        }

        int arrayCount = CGPDFArrayGetCount( rectArray );
        CGPDFReal coords[4];
        for( int k = 0; k < arrayCount; ++k ) {
            CGPDFObjectRef rectObj;
            if(!CGPDFArrayGetObject(rectArray, k, &rectObj)) {
                return;
            }

            CGPDFReal coord;
            if(!CGPDFObjectGetValue(rectObj, kCGPDFObjectTypeReal, &coord)) {
                return;
            }

            coords[k] = coord;
        }               

        char *uriString = (char *)CGPDFStringGetBytePtr(uriStringRef);

        NSString *uri = [NSString stringWithCString:uriString encoding:NSUTF8StringEncoding];
        CGRect rect = CGRectMake(coords[0],coords[1],coords[2],coords[3]);

        CGPDFInteger pageRotate = 0;
        CGPDFDictionaryGetInteger( pageDictionary, "Rotate", &pageRotate ); 
        CGRect pageRect = CGRectIntegral( CGPDFPageGetBoxRect( page, kCGPDFMediaBox ));
        if( pageRotate == 90 || pageRotate == 270 ) {
            CGFloat temp = pageRect.size.width;
            pageRect.size.width = pageRect.size.height;
            pageRect.size.height = temp;
        }

        rect.size.width -= rect.origin.x;
        rect.size.height -= rect.origin.y;

        CGAffineTransform trans = CGAffineTransformIdentity;
        trans = CGAffineTransformTranslate(trans, 0, pageRect.size.height);
        trans = CGAffineTransformScale(trans, 1.0, -1.0);

        rect = CGRectApplyAffineTransform(rect, trans);

        // do whatever you need with the coordinates.
        // e.g. you could create a button and put it on top of your page
        // and use it to open the URL with UIApplication's openURL
    }
}

Answer 1

这是至少为每个页面获取annots CGPDFDictionary的基本思想。之后，您应该能够在Adobe的PDF规范的帮助下弄明白。

1。）获取CGPDFDocumentRef。

2。）获取每一页。

3。）在每个页面上，使用CGPDFDictionaryGetArray(pageDictionary, "Annots", &outputArray)，其中pageDictionary是表示CGPDFPage的CGPDFDictionary，而outputArray是用于存储该页面的Annots数组的变量（CGPDFArrayRef）。

Answer 2

很棒的代码，但我在项目中遇到了一些麻烦。它正确地获取了所有URL，但是当我点击它时没有任何反应。这是我的代码，我必须稍微修改你的代码才能使用我的项目）。有什么遗漏：

- (void) renderPageAtIndex:(NSUInteger)index inContext:(CGContextRef)ctx {
//CGPDFPageRef page = CGPDFDocumentGetPage(pdf, index+1);

CGPDFPageRef page = CGPDFDocumentGetPage(pdf, index+1);
CGAffineTransform transform1 = aspectFit(CGPDFPageGetBoxRect(page, kCGPDFMediaBox),
                                         CGContextGetClipBoundingBox(ctx));
CGContextConcatCTM(ctx, transform1);
CGContextDrawPDFPage(ctx, page);

int pageCount = CGPDFDocumentGetNumberOfPages(pdf);
int i = 0;
while (i<pageCount) {
    i++;
    CGPDFPageRef page = CGPDFDocumentGetPage(pdf, i+1);

    CGPDFDictionaryRef pageDictionary = CGPDFPageGetDictionary(page);

    CGPDFArrayRef outputArray;
    if(!CGPDFDictionaryGetArray(pageDictionary, "Annots", &outputArray)) {
        return;
    }

    int arrayCount = CGPDFArrayGetCount( outputArray );
    if(!arrayCount) {
        continue;
    }

    for( int j = 0; j < arrayCount; ++j ) {
        CGPDFObjectRef aDictObj;
        if(!CGPDFArrayGetObject(outputArray, j, &aDictObj)) {
            return;
        }

        CGPDFDictionaryRef annotDict;
        if(!CGPDFObjectGetValue(aDictObj, kCGPDFObjectTypeDictionary, &annotDict)) {
            return;
        }

        CGPDFDictionaryRef aDict;
        if(!CGPDFDictionaryGetDictionary(annotDict, "A", &aDict)) {
            return;
        }

        CGPDFStringRef uriStringRef;
        if(!CGPDFDictionaryGetString(aDict, "URI", &uriStringRef)) {
            return;
        }

        CGPDFArrayRef rectArray;
        if(!CGPDFDictionaryGetArray(annotDict, "Rect", &rectArray)) {
            return;
        }

        int arrayCount = CGPDFArrayGetCount( rectArray );
        CGPDFReal coords[4];
        for( int k = 0; k < arrayCount; ++k ) {
            CGPDFObjectRef rectObj;
            if(!CGPDFArrayGetObject(rectArray, k, &rectObj)) {
                return;
            }

            CGPDFReal coord;
            if(!CGPDFObjectGetValue(rectObj, kCGPDFObjectTypeReal, &coord)) {
                return;
            }

            coords[k] = coord;
        }               

        char *uriString = (char *)CGPDFStringGetBytePtr(uriStringRef);

        NSString *uri = [NSString stringWithCString:uriString encoding:NSUTF8StringEncoding];
        CGRect rect = CGRectMake(coords[0],coords[1],coords[2],coords[3]);

        CGPDFInteger pageRotate = 0;
        CGPDFDictionaryGetInteger( pageDictionary, "Rotate", &pageRotate ); 
        CGRect pageRect = CGRectIntegral( CGPDFPageGetBoxRect( page, kCGPDFMediaBox ));
        if( pageRotate == 90 || pageRotate == 270 ) {
            CGFloat temp = pageRect.size.width;
            pageRect.size.width = pageRect.size.height;
            pageRect.size.height = temp;
        }

        rect.size.width -= rect.origin.x;
        rect.size.height -= rect.origin.y;

        CGAffineTransform trans = CGAffineTransformIdentity;
        trans = CGAffineTransformTranslate(trans, 0, pageRect.size.height);
        trans = CGAffineTransformScale(trans, 1.0, -1.0);

        rect = CGRectApplyAffineTransform(rect, trans);

        // do whatever you need with the coordinates.
        // e.g. you could create a button and put it on top of your page
        // and use it to open the URL with UIApplication's openURL
        NSURL *url = [NSURL URLWithString:uri];
        NSLog(@"URL: %@", url);
        CGPDFContextSetURLForRect(ctx, (CFURLRef)url, rect);
       // CFRelease(url);
        }
    }   


}

谢谢＆amp;伟大的工作BrainFeeder！

更新：

对于在您的应用程序中使用leaves项目的任何人来说，这就是我如何使用PDF链接工作（它不完美，因为rect似乎填满整个屏幕，但它是一个开始）：

- (void) renderPageAtIndex:(NSUInteger)index inContext:(CGContextRef)ctx {

CGPDFPageRef page = CGPDFDocumentGetPage(pdf, index+1);
CGAffineTransform transform1 = aspectFit(CGPDFPageGetBoxRect(page, kCGPDFMediaBox),
                                         CGContextGetClipBoundingBox(ctx));
CGContextConcatCTM(ctx, transform1);
CGContextDrawPDFPage(ctx, page);


    CGPDFPageRef pageAd = CGPDFDocumentGetPage(pdf, index);

    CGPDFDictionaryRef pageDictionary = CGPDFPageGetDictionary(pageAd);

    CGPDFArrayRef outputArray;
    if(!CGPDFDictionaryGetArray(pageDictionary, "Annots", &outputArray)) {
        return;
    }

    int arrayCount = CGPDFArrayGetCount( outputArray );
    if(!arrayCount) {
        //continue;
    }

    for( int j = 0; j < arrayCount; ++j ) {
        CGPDFObjectRef aDictObj;
        if(!CGPDFArrayGetObject(outputArray, j, &aDictObj)) {
            return;
        }

        CGPDFDictionaryRef annotDict;
        if(!CGPDFObjectGetValue(aDictObj, kCGPDFObjectTypeDictionary, &annotDict)) {
            return;
        }

        CGPDFDictionaryRef aDict;
        if(!CGPDFDictionaryGetDictionary(annotDict, "A", &aDict)) {
            return;
        }

        CGPDFStringRef uriStringRef;
        if(!CGPDFDictionaryGetString(aDict, "URI", &uriStringRef)) {
            return;
        }

        CGPDFArrayRef rectArray;
        if(!CGPDFDictionaryGetArray(annotDict, "Rect", &rectArray)) {
            return;
        }

        int arrayCount = CGPDFArrayGetCount( rectArray );
        CGPDFReal coords[4];
        for( int k = 0; k < arrayCount; ++k ) {
            CGPDFObjectRef rectObj;
            if(!CGPDFArrayGetObject(rectArray, k, &rectObj)) {
                return;
            }

            CGPDFReal coord;
            if(!CGPDFObjectGetValue(rectObj, kCGPDFObjectTypeReal, &coord)) {
                return;
            }

            coords[k] = coord;
        }               

        char *uriString = (char *)CGPDFStringGetBytePtr(uriStringRef);

        NSString *uri = [NSString stringWithCString:uriString encoding:NSUTF8StringEncoding];
        CGRect rect = CGRectMake(coords[0],coords[1],coords[2],coords[3]);

        CGPDFInteger pageRotate = 0;
        CGPDFDictionaryGetInteger( pageDictionary, "Rotate", &pageRotate ); 
        CGRect pageRect = CGRectIntegral( CGPDFPageGetBoxRect( page, kCGPDFMediaBox ));
        if( pageRotate == 90 || pageRotate == 270 ) {
            CGFloat temp = pageRect.size.width;
            pageRect.size.width = pageRect.size.height;
            pageRect.size.height = temp;
        }

        rect.size.width -= rect.origin.x;
        rect.size.height -= rect.origin.y;

        CGAffineTransform trans = CGAffineTransformIdentity;
        trans = CGAffineTransformTranslate(trans, 0, pageRect.size.height);
        trans = CGAffineTransformScale(trans, 1.0, -1.0);

        rect = CGRectApplyAffineTransform(rect, trans);

            // do whatever you need with the coordinates.
            // e.g. you could create a button and put it on top of your page
            // and use it to open the URL with UIApplication's openURL
            NSURL *url = [NSURL URLWithString:uri];
            NSLog(@"URL: %@", url);
//          CGPDFContextSetURLForRect(ctx, (CFURLRef)url, rect);
            UIButton *button = [[UIButton alloc] initWithFrame:rect];
            [button setTitle:@"LINK" forState:UIControlStateNormal];
            [button addTarget:self action:@selector(openLink:) forControlEvents:UIControlEventTouchUpInside];
            [self.view addSubview:button];
           // CFRelease(url);
        }
    //} 

最终更新 以下是我在我的应用中使用的最终代码。

- (void) renderPageAtIndex:(NSUInteger)index inContext:(CGContextRef)ctx {
//If the view already contains a button control remove it
if ([[self.view subviews] containsObject:button]) {
    [button removeFromSuperview];
}

CGPDFPageRef page = CGPDFDocumentGetPage(pdf, index+1);
CGAffineTransform transform1 = aspectFit(CGPDFPageGetBoxRect(page, kCGPDFMediaBox),
                                         CGContextGetClipBoundingBox(ctx));
CGContextConcatCTM(ctx, transform1);
CGContextDrawPDFPage(ctx, page);


CGPDFPageRef pageAd = CGPDFDocumentGetPage(pdf, index);

CGPDFDictionaryRef pageDictionary = CGPDFPageGetDictionary(pageAd);

CGPDFArrayRef outputArray;
if(!CGPDFDictionaryGetArray(pageDictionary, "Annots", &outputArray)) {
    return;
}

int arrayCount = CGPDFArrayGetCount( outputArray );
if(!arrayCount) {
    //continue;
}

for( int j = 0; j < arrayCount; ++j ) {
    CGPDFObjectRef aDictObj;
    if(!CGPDFArrayGetObject(outputArray, j, &aDictObj)) {
        return;
    }

    CGPDFDictionaryRef annotDict;
    if(!CGPDFObjectGetValue(aDictObj, kCGPDFObjectTypeDictionary, &annotDict)) {
        return;
    }

    CGPDFDictionaryRef aDict;
    if(!CGPDFDictionaryGetDictionary(annotDict, "A", &aDict)) {
        return;
    }

    CGPDFStringRef uriStringRef;
    if(!CGPDFDictionaryGetString(aDict, "URI", &uriStringRef)) {
        return;
    }

    CGPDFArrayRef rectArray;
    if(!CGPDFDictionaryGetArray(annotDict, "Rect", &rectArray)) {
        return;
    }

    int arrayCount = CGPDFArrayGetCount( rectArray );
    CGPDFReal coords[4];
    for( int k = 0; k < arrayCount; ++k ) {
        CGPDFObjectRef rectObj;
        if(!CGPDFArrayGetObject(rectArray, k, &rectObj)) {
            return;
        }

        CGPDFReal coord;
        if(!CGPDFObjectGetValue(rectObj, kCGPDFObjectTypeReal, &coord)) {
            return;
        }

        coords[k] = coord;
    }               

    char *uriString = (char *)CGPDFStringGetBytePtr(uriStringRef);

    NSString *uri = [NSString stringWithCString:uriString encoding:NSUTF8StringEncoding];
    CGRect rect = CGRectMake(coords[0],coords[1],coords[2],coords[3]);
    CGPDFInteger pageRotate = 0;
    CGPDFDictionaryGetInteger( pageDictionary, "Rotate", &pageRotate ); 
    CGRect pageRect = CGRectIntegral( CGPDFPageGetBoxRect( page, kCGPDFMediaBox ));
    if( pageRotate == 90 || pageRotate == 270 ) {
        CGFloat temp = pageRect.size.width;
        pageRect.size.width = pageRect.size.height;
        pageRect.size.height = temp;
    }

    rect.size.width -= rect.origin.x;
    rect.size.height -= rect.origin.y;

    CGAffineTransform trans = CGAffineTransformIdentity;
    trans = CGAffineTransformTranslate(trans, 35, pageRect.size.height+150);
    trans = CGAffineTransformScale(trans, 1.15, -1.15);

    rect = CGRectApplyAffineTransform(rect, trans);

    urlLink = [NSURL URLWithString:uri];
    [urlLink retain];

    //Create a button to get link actions
    button = [[UIButton alloc] initWithFrame:rect];
    [button setBackgroundImage:[UIImage imageNamed:@"link_bg.png"] forState:UIControlStateHighlighted];
    [button addTarget:self action:@selector(openLink:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button];
}   
[leavesView reloadData];
}

}

Answer 3

我必须感到困惑，因为如果我使用这一切都有效：

CGRect rect = CGRectMake(coords[0],coords[1],coords[2]-coords[0]+1,coords[3]-coords[1]+1);

我可能会在以后滥用某些东西吗？ PDF提供了角落，而CGRect想要一个角落和一个大小。