截取PDF的某一页 iOS

最新推荐文章于 2024-10-16 13:58:13 发布

原创最新推荐文章于 2024-10-16 13:58:13 发布 · 1.5k 阅读

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文章标签：

#OC #iOS开发 #ios #pdf #Objective-C

这篇博客介绍了如何在iOS应用中截取并保存PDF的某一页到本地。ReaderDocument类提供了两个方法，一个用于保存指定页，另一个用于删除相应页面。代码涉及到CGPDFDocumentRef和UIGraphicsBeginPDFContextToFile等技术，通过CGPDFPageGetDrawingTransform和CGPDFDocumentGetPage等API来处理PDF页面。

项目中，可能需要截取某一份PDF喜欢的页面，所以需要进行对PDF进行切割。网上找了好多资源都没解决。下面附上基于Reader第三方的解决方法。

在ReaderDocument.h中暴露两个方法

/**

保存PDF的某一页到本地

+ (void) saveOnePDFPageWithDocument:(ReaderDocument *)document pdfID:(NSString *)pdfID FileName:(NSString *)fileName;

/**

删除保存在本地的PDF、通过相同的文件名删除

+ (void) deleteOnePDFPageWithDocument:(ReaderDocument *)document pdfID:(NSString *)pdfID FileName:(NSString *)fileName;

=====================================
ReaderDocument.m中实现两个方法

///////////////////////////////删除本地相同PDF名称页面///////////////////////////////////

+ (void) deleteOnePDFPageWithDocument:(ReaderDocument *)document pdfID:(NSString *)pdfID FileName:(NSString *)fileName

{

//创建文件管理器

NSFileManager *fileManager = [NSFileManager defaultManager];

NSString *tmpFolder=[NSString stringWithFormat:@"%@/tmp/%@-%@",NSHomeDirectory(),fileName,pdfID];

NSLog(@"地址是：%@",tmpFolder);

BOOL fileExists = [fileManager fileExistsAtPath:tmpFolder];

if (fileExists) {//如果不存在说创建

NSError *err;

[fileManager removeItemAtPath:tmpFolder error:&err];

NSLog(@"%@",err);

}

+ (void) saveOnePDFPageWithDocument:(ReaderDocument *)document pdfID:(NSString *)pdfID FileName:(NSString *)fileName

{

//创建文件管理器

NSFileManager *fileManager = [NSFileManager defaultManager];

NSString *tmpFolder=[NSString stringWithFormat:@"%@/tmp",NSHomeDirectory()];

NSLog(@"保存地址是：%@",tmpFolder);

BOOL fileExists = [fileManager fileExistsAtPath:tmpFolder];

if (!fileExists) {//如果不存在说创建

[fileManager createDirectoryAtPath:tmpFolder

withIntermediateDirectories:YES

attributes:nil

error:nil];

}

CGPDFDocumentRef doc = CGPDFDocumentCreateUsingUrl((__bridge CFURLRef)document.fileURL, document.password);

// NSLog(@"合并地址是：%@",document.fileURL);

NSString *signFileName=[NSString stringWithFormat:@"%@-%@",fileName,pdfID];

//[signFileName stringByAppendingString:iName];

NSString *tempPath = [NSTemporaryDirectory() stringByAppendingString:signFileName];

//CGRectZero means the default page size is 8.5x11

//We don't care about the default anyway, because we set each page to be a specific size

UIGraphicsBeginPDFContextToFile(tempPath, CGRectZero, nil);

//Iterate over each page - 1-based indexing (obnoxious...)

// 获取当前页码

for (int i = [pdfID intValue]; i <= [pdfID intValue]; i++) {

CGPDFPageRef page = CGPDFDocumentGetPage (doc, i); // grab page i of the PDF

CGRect tmpRect = [ReaderDocument boundsForPDFPage:page];

//Create a new page

UIGraphicsBeginPDFPageWithInfo(tmpRect, nil);

CGContextRef context = UIGraphicsGetCurrentContext();

// flip context so page is right way up

CGContextTranslateCTM(context, 0.0, tmpRect.size.height);

CGContextScaleCTM(context, 1.0, -1.0);

int angle = CGPDFPageGetRotationAngle(page);

if (angle != 0 && angle !=180) {

CGContextConcatCTM(context, CGPDFPageGetDrawingTransform(page, kCGPDFMediaBox, tmpRect, 0, false));

}

CGContextDrawPDFPage (context, page); // draw the page into graphics context

CGContextScaleCTM(context, 1.0, -1.0);

CGContextTranslateCTM(context, 0, -tmpRect.size.height);

if (angle != 0 && angle !=180) {

CGContextConcatCTM(context, CGPDFPageGetDrawingTransform(page, kCGPDFCropBox, tmpRect, 0, false));

}

UIGraphicsEndPDFContext();

CGPDFDocumentRelease (doc);

}

#pragma mark-

+ (CGRect) boundsForPDFPage:(CGPDFPageRef) page{

CGRect cropBoxRect = CGPDFPageGetBoxRect(page, kCGPDFCropBox);

CGRect mediaBoxRect = CGPDFPageGetBoxRect(page, kCGPDFMediaBox);

CGRect effectiveRect = CGRectIntersection(cropBoxRect, mediaBoxRect);

int pageAngle = CGPDFPageGetRotationAngle(page); // Angle

float pageWidth, pageHeight, pageOffsetX, pageOffsetY;

switch (pageAngle) // Page rotation angle (in degrees)

{

default: // Default case

case 0: case 180: // 0 and 180 degrees

{

pageWidth = effectiveRect.size.width;

pageHeight = effectiveRect.size.height;

pageOffsetX = effectiveRect.origin.x;

pageOffsetY = effectiveRect.origin.y;

break;

}

case 90: case 270: // 90 and 270 degrees

{

pageWidth = effectiveRect.size.height;

pageHeight = effectiveRect.size.width;

pageOffsetX = effectiveRect.origin.y;

pageOffsetY = effectiveRect.origin.x;

break;

}

return CGRectMake(pageOffsetX, pageOffsetY, pageWidth, pageHeight);

}

///////////////////////////////保存某一个单独PDF页面///////////////////////////////////

在ReaderViewController.m添加标签实现删除、保存功能

- (void)tappedInToolbar:(ReaderMainToolbar *)toolbar markButton:(UIButton *)button

{

if (printInteraction != nil) [printInteraction dismissAnimated:YES];

NSString *pdfID = [NSString stringWithFormat:@"%lu",(long)currentPage];

NSString *fileName = [document.fileName stringByReplacingOccurrencesOfString:@".pdf" withString:@""];

if ([document.bookmarks containsIndex:currentPage]) // Remove bookmark

{

[document.bookmarks removeIndex:currentPage]; [mainToolbar setBookmarkState:NO];

//删除PDF

[ReaderDocument deleteOnePDFPageWithDocument:document pdfID:pdfID FileName:fileName];

}

else // Add the bookmarked page number to the bookmark index set

{

[document.bookmarks addIndex:currentPage]; [mainToolbar setBookmarkState:YES];

//合并PDF，历史图层，text图层方法、保存涂鸦笔记

[ReaderDocument saveOnePDFPageWithDocument:document pdfID:pdfID FileName:fileName];

}