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iOS实现PDF文件浏览功能

2020-07-26 02:20:17
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写了一个小Demo,显示本地PDF格式文件,支持翻页、跳页、缩放。 

先看一下效果图:

iOS开发,显示PDF格式文件方法有很多:

  • 最简单的应该是UIWebView,可以加载本地或网络PDF文件,支持上下滑动浏览、缩放。
  • 优化一点的是用系统的QLPreviewController加载,实现起来也比较方便,支持上下滑动浏览,左后滑动可多PDF文件切换,同时支持原生的分享打印,QLPreviewController支持的文档格式也比较多,如pdf、doc、docx、xls、xlsx、txt、ppt、mp4...
  • 上面两种都没有足够的自定义空间,不在这里做过多的介绍了,另外一种也就是本篇用到的iOS核心图形库:Core Graphics,绘制PDF文档。

简单说一下逻辑,根据本地路径获取到CGPDFDocumentRef,在drawRect中绘制上下文,画出PDF文件。通过UIScrollView实现缩放,添加UIGestureRecognizer实现单击、双击、左滑、右滑功能。基于CATransition实现翻页动画。

下面贴上核心代码:

承载PDF文件视图的控制器:HWPDFBrowseVC

#import <UIKit/UIKit.h> @interface HWPDFBrowseVC : UIViewController @property (nonatomic, copy) NSString *filePath;@property (nonatomic, copy) NSString *fileName; @end /*** ---------------分割线--------------- ***/ #import "HWPDFBrowseVC.h"#import "HWPDFBrowseView.h"#import "HWPDFBrowseToolBar.h"#import "HWPDFBrowseScrollView.h" #define KPicMaxScale 3.0#define KMainW [UIScreen mainScreen].bounds.size.width#define KMainH [UIScreen mainScreen].bounds.size.height @interface HWPDFBrowseVC ()<UIScrollViewDelegate, HWPDFBroeseToolBarDelegate> @property (nonatomic, weak) HWPDFBrowseScrollView *scrollView;@property (nonatomic, weak) HWPDFBrowseView *browseView;@property (nonatomic, weak) HWPDFBrowseToolBar *toolBar;@property (nonatomic, assign) CGFloat minZoomScale;@property (nonatomic, assign) CGFloat lastScrContX; @end @implementation HWPDFBrowseVC - (void)viewDidLoad { [super viewDidLoad];  //初始化 self.view.backgroundColor = [UIColor whiteColor]; self.navigationItem.title = _fileName;  //创建控件 [self creatControl];} - (void)viewWillDisappear:(BOOL)animated{ [super viewWillDisappear:animated];  //防止隐藏导航时,左滑返回导航消失 CGRect temNavBarFrame = self.navigationController.navigationBar.frame; temNavBarFrame.origin.y = 20; self.navigationController.navigationBar.frame = temNavBarFrame;} - (void)creatControl{ //导航右侧按钮 UIButton *deleteBtn = [[UIButton alloc] initWithFrame:CGRectMake(9, 0, 40, 40)]; deleteBtn.titleLabel.font = [UIFont systemFontOfSize:16.f]; [deleteBtn setTitle:@"跳页" forState:UIControlStateNormal]; [deleteBtn setTitleColor:[UIColor blueColor] forState:UIControlStateNormal]; [deleteBtn addTarget:self action:@selector(navBtnOnClick) forControlEvents:UIControlEventTouchUpInside]; UIView *rightView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 40, 40)]; [rightView addSubview:deleteBtn]; self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:rightView];  //scrollView HWPDFBrowseScrollView *scrollView = [[HWPDFBrowseScrollView alloc] initWithFrame:[UIScreen mainScreen].bounds]; scrollView.delegate = self; scrollView.backgroundColor = [UIColor blackColor]; scrollView.maximumZoomScale = KPicMaxScale; scrollView.showsVerticalScrollIndicator = NO; scrollView.showsHorizontalScrollIndicator = NO; [self.view addSubview:scrollView]; _scrollView = scrollView;  //pdf视图 HWPDFBrowseView *browseView = [[HWPDFBrowseView alloc] initWithFilePath:_filePath]; [scrollView addSubview:browseView]; _browseView = browseView;  //绘制pdf视图后缩放至屏幕完全居中显示 CGRect frame = browseView.frame; frame.size.width = browseView.frame.size.width > KMainW ? KMainW : browseView.frame.size.width; frame.size.height = frame.size.width * (browseView.frame.size.height / browseView.frame.size.width); if (frame.size.height > KMainH) { frame.size.height = KMainH; frame.size.width = KMainH * (browseView.frame.size.width / browseView.frame.size.height); }  //根据缩放调整 _minZoomScale = frame.size.width / browseView.frame.size.width; scrollView.allowScrollScale = _minZoomScale; scrollView.minimumZoomScale = _minZoomScale; scrollView.zoomScale = _minZoomScale;  //底部工具栏 HWPDFBrowseToolBar *toolBar = [[HWPDFBrowseToolBar alloc] initWithFrame:CGRectMake(0, KMainH - 49, KMainW, 49) currentPage:_browseView.currentPage totalPage:_browseView.totalPages]; toolBar.delegate = self; [self.view addSubview:toolBar]; _toolBar = toolBar;  //单击 UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(click)]; tap.numberOfTouchesRequired = 1; tap.numberOfTapsRequired = 1; [scrollView addGestureRecognizer:tap];  //双击 UITapGestureRecognizer *tapDouble = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(doubleClick)]; tapDouble.numberOfTapsRequired = 2; [scrollView addGestureRecognizer:tapDouble]; [tap requireGestureRecognizerToFail:tapDouble];  //右滑手势 UISwipeGestureRecognizer *rightSwip = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(nextPage)]; rightSwip.direction = UISwipeGestureRecognizerDirectionLeft; [scrollView addGestureRecognizer:rightSwip];  //左滑手势 UISwipeGestureRecognizer *leftSwip = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(forwardPage)]; leftSwip.direction = UISwipeGestureRecognizerDirectionRight; [scrollView addGestureRecognizer:leftSwip];} - (void)navBtnOnClick{ [_toolBar showWindow];} //单击屏幕显示隐藏菜单- (void)click{ CGFloat navBarY = _toolBar.frame.origin.y == KMainH - 49 ? -64 : 20; CGFloat toolBarY = _toolBar.frame.origin.y == KMainH - 49 ? KMainH : KMainH - 49;  [UIView animateWithDuration:0.25 animations:^{ CGRect temNavBarFrame = self.navigationController.navigationBar.frame; temNavBarFrame.origin.y = navBarY; self.navigationController.navigationBar.frame = temNavBarFrame; CGRect temToolBarFrame = _toolBar.frame; temToolBarFrame.origin.y = toolBarY; _toolBar.frame = temToolBarFrame; }];} //双击屏幕放大缩小图片- (void)doubleClick{ [UIView animateWithDuration:0.25f animations:^{ _scrollView.zoomScale = _scrollView.zoomScale == _minZoomScale ? KPicMaxScale : _minZoomScale; }];} //左滑事件- (void)nextPage{ [_browseView nextPage]; _toolBar.currentPage = _browseView.currentPage;} //右滑事件- (void)forwardPage{ [_browseView prePage]; _toolBar.currentPage = _browseView.currentPage;} #pragma mark - UICouseBrowseToolBarDelegate- (void)browseToolBar:(HWPDFBrowseToolBar *)browseToolBar didClickFinishButtonWithPage:(NSString *)page{ _browseView.currentPage = [page integerValue]; [_browseView reloadView]; [_toolBar dismissKeyboard]; _scrollView.zoomScale = _minZoomScale;} - (void)browseToolBar:(HWPDFBrowseToolBar *)browseToolBar didPageButtonWithAction:(BOOL)nextPage{ if (nextPage) { [self nextPage]; }else { [self forwardPage]; } _scrollView.zoomScale = _minZoomScale;} #pragma mark - UIScrollViewDelegate- (void)scrollViewDidZoom:(UIScrollView *)scrollView{ CGFloat offsetX = (scrollView.bounds.size.width > scrollView.contentSize.width) ? (scrollView.bounds.size.width - scrollView.contentSize.width) * 0.5 : 0.0; CGFloat offsetY = (scrollView.bounds.size.height > scrollView.contentSize.height) ? (scrollView.bounds.size.height - scrollView.contentSize.height) * 0.5 : 0.0; _browseView.center = CGPointMake(scrollView.contentSize.width * 0.5 + offsetX, scrollView.contentSize.height * 0.5 + offsetY - 64);} - (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView{ return _browseView;} - (void)scrollViewDidScroll:(UIScrollView *)scrollView{ if (scrollView.isZooming) return;  //允许翻页的偏移量 CGFloat movePadding = 70.f;  //仿苹果原生相册,图片放大后,滑动前在边界时在可以翻页,这里加了±10的偏移量 if (scrollView.contentOffset.x < - movePadding && _lastScrContX < 10) { _scrollView.zoomScale = _minZoomScale; [self forwardPage]; }  if (scrollView.contentSize.width - scrollView.contentOffset.x < KMainW - movePadding && scrollView.contentSize.width != 0 && fabsf(_lastScrContX + KMainW - scrollView.contentSize.width) < 10) { _scrollView.zoomScale = _minZoomScale; [self nextPage]; }} //滑动自然停止时调用- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{ _lastScrContX = scrollView.contentOffset.x;} //滑动手动停止时调用- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{ _lastScrContX = scrollView.contentOffset.x;} - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated.} @end

PDF文件视图:HWPDFBrowseView

#import <UIKit/UIKit.h> @interface HWPDFBrowseView : UIView{ CGPDFDocumentRef pdfDocumentRef;} @property (nonatomic, assign) NSInteger currentPage;@property (nonatomic, assign) NSInteger totalPages; - (id)initWithFilePath:(NSString *)filePath;- (void)reloadView;- (void)prePage;- (void)nextPage; @end /*** ---------------分割线--------------- ***/ #import "HWPDFBrowseView.h" @implementation HWPDFBrowseView - (id)initWithFilePath:(NSString *)filePath{ pdfDocumentRef = [self createPDFFromExistFile:filePath];  self = [super initWithFrame:CGPDFPageGetBoxRect(CGPDFDocumentGetPage(pdfDocumentRef, 1), kCGPDFMediaBox)];  return self;} - (CGPDFDocumentRef)createPDFFromExistFile:(NSString *)aFilePath{ CFStringRef path = CFStringCreateWithCString(NULL, [aFilePath UTF8String], kCFStringEncodingUTF8); CFURLRef urlRef = CFURLCreateWithFileSystemPath(NULL, path, kCFURLPOSIXPathStyle, NO); CFRelease(path); CGPDFDocumentRef document = CGPDFDocumentCreateWithURL(urlRef); CFRelease(urlRef); _totalPages = CGPDFDocumentGetNumberOfPages(document); _currentPage = 1; if (_totalPages == 0) return NULL;  return document;} - (void)reloadView{ [self setNeedsDisplay];} - (void)drawRect:(CGRect)rect{ CGContextRef context = UIGraphicsGetCurrentContext(); [[UIColor whiteColor] set]; CGContextFillRect(context, rect); CGContextTranslateCTM(context, 0.0, rect.size.height); CGContextScaleCTM(context, 1.0, -1.0); CGPDFPageRef page = CGPDFDocumentGetPage(pdfDocumentRef, _currentPage); CGAffineTransform pdfTransform = CGPDFPageGetDrawingTransform(page, kCGPDFCropBox, rect, 0, true); CGContextConcatCTM(context, pdfTransform); CGContextDrawPDFPage(context, page);} //上一页- (void)prePage{ if(_currentPage < 2) { UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"提示" message:@"已经第一页了!" delegate:self cancelButtonTitle:@"确定" otherButtonTitles: nil ]; [alert show]; return; }  --_currentPage; [self reloadView]; [self transitionWithType:@"pageUnCurl" WithSubtype:kCATransitionFromRight ForView:self];} //下一页- (void)nextPage{ if(_currentPage >= _totalPages) { UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"提示" message:@"已经最后一页了!" delegate:self cancelButtonTitle:@"确定" otherButtonTitles: nil ]; [alert show]; return; }  ++_currentPage; [self reloadView]; [self transitionWithType:@"pageCurl" WithSubtype:kCATransitionFromRight ForView:self];} //设置翻页动画效果- (void)transitionWithType:(NSString *)type WithSubtype:(NSString *)subtype ForView:(UIView *)view{ CATransition *animation = [CATransition animation]; animation.duration = 0.7f; animation.type = type; if (subtype) animation.subtype = subtype; animation.timingFunction = UIViewAnimationOptionCurveEaseInOut; [view.layer addAnimation:animation forKey:@"animation"];} @end

Demo 下载链接

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