最近有个朋友想做一个pdf预览，要求能够上下滑动翻页、带缩放、目录跳转功能。
因为之前我只做过简单的预览，那时直接用uiwebview实现的，这次找了下资料，发现一个比较好的库。
其原理实现：
自定义uiview来显示pdf+使用的是苹果官方的api读取目录+uiscrollview实现缩放及翻页。
不过这个库是左右翻页的，我不是很习惯，就改成了上下滑动翻页，并且在底部添加了页码显示（1/10格式）。
效果图如下：
其中几段核心代码：
1、加载pdf文件
CFURLRef pdfURL = CFBundleCopyResourceURL(CFBundleGetMainBundle(), (__bridge CFStringRef)@"002.pdf", NULL, NULL);
pdfDocument = CGPDFDocumentCreateWithURL((CFURLRef)pdfURL);
CFRelease(pdfURL);
2、获取pdf文件目录
#pragma mark 获取pdf文件目录
- (NSArray *)getPDFContents: (CGPDFDocumentRef) myDocument
{ CGPDFDictionaryRef mycatalog= CGPDFDocumentGetCatalog(myDocument);
CommentNode *rootNode = [[CommentNode alloc] initWithCatalog:mycatalog];
CommentNode *rootOutlineNode = [rootNode childrenForName:@"/Outlines"];
CommentNode *pagesNode = [rootNode childrenForName:@"/Pages"];
NSArray *pagesArray = [self getPagesFromPagesNode:pagesNode];
CommentNode *destsNode = [rootNode childrenForName:@"/Dests"]; return [self getContentsForOutlineNode:rootOutlineNode pages:pagesArray destsNode:destsNode];
} - (NSArray *)getContentsForOutlineNode:(CommentNode *)rootOutlineNode pages:(NSArray *)pagesArray destsNode:(CommentNode *)destsNode
{
NSMutableArray *outlineArray = [[NSMutableArray alloc] init];
CommentNode *firstOutlineNode = [rootOutlineNode childrenForName:@"/First"];
CommentNode *outlineNode = firstOutlineNode;
while (outlineNode) {
NSString *title = [[outlineNode childrenForName:@"/Title"] value];
CommentNode *destNode = [outlineNode childrenForName:@"/Dest"];
NSMutableDictionary *outline = [NSMutableDictionary dictionaryWithDictionary:@{@"Title": title}];
int index = ;
if (destNode) {
if ([[destNode typeAsString] isEqualToString:@"Array"]) {
CGPDFObjectRef dest = (__bridge CGPDFObjectRef)[[[destNode children] objectAtIndex:] object];
index = [self getIndexInPages:pagesArray forPage:dest];
} else if ([[destNode typeAsString] isEqualToString:@"Name"]) {
NSString *destName = [destNode value];
CGPDFObjectRef dest = (__bridge CGPDFObjectRef)[[[[[destsNode childrenForName:destName] childrenForName:@"/D"] children] objectAtIndex:] object];
index = [self getIndexInPages:pagesArray forPage:dest];
}
} else {
CommentNode *aNode = [outlineNode childrenForName:@"/A"];
if (aNode) {
CommentNode *dNode = [aNode childrenForName:@"/D"];
if (dNode) {
CommentNode *d0Node = [[dNode children] objectAtIndex:];
if ([[d0Node typeAsString] isEqualToString:@"Dictionary"]) {
CGPDFObjectRef dest = (CGPDFObjectRef)[d0Node object];
index = [self getIndexInPages:pagesArray forPage:dest];
}
}
}
}
[outline setObject:@(index) forKey:@"Index"];
NSArray *subOutlines = [self getContentsForOutlineNode:outlineNode pages:pagesArray destsNode:destsNode];
[outline setObject:subOutlines forKey:@"SubContents"];
[outlineArray addObject:outline];
outlineNode = [outlineNode childrenForName:@"/Next"];
}
return outlineArray;
} - (NSArray *)getPagesFromPagesNode:(CommentNode *)pagesNode
{
NSMutableArray *pages = [NSMutableArray new];
CommentNode *kidsNode = [pagesNode childrenForName:@"/Kids"];
for (CommentNode *node in [kidsNode children]) {
NSString *type = [[node childrenForName:@"/Type"] value];
if ([type isEqualToString:@"/Pages"]) {
NSArray *kidsPages = [self getPagesFromPagesNode:node];
[pages addObjectsFromArray:kidsPages];
} else {
[pages addObject:node];
}
}
return pages;
} - (int)getIndexInPages:(NSArray *)pages forPage:(CGPDFObjectRef)page
{
for (int k = ; k < pages.count; k++) {
CommentNode *node = [pages objectAtIndex:k];
if ([node object] == page)
return k+;
}
return ;
}
源码获取：https://github.com/TangledHusky/YJ-PDFReader/tree/master
特别鸣谢：
参考文献：https://blog.csdn.net/shenshucong520/article/details/51578695