关于UIWebView 加载网络PDF 实现翻页效果的那些事
首先呢 这里说的是加载网络的pdf 可不是本地的哦
新建一个view 主要是用于循环渲染绘制pdf单页面内容
.h重写init方法 用于自定义 接收docRef文件和传入的page页面
- (instancetype)initWithFrame:(CGRect)frame documentRef:(CGPDFDocumentRef)docRef andPageNum:(int)page;
.m页面呢 实现方法 并且需要属性方法
CGPDFDocumentRef documentRef; 这个是pdf接收的doc文件类型
NSInteger pageNum; 接收当前的page
- (instancetype)initWithFrame:(CGRect)frame documentRef:(CGPDFDocumentRef)docRef andPageNum:(int)page{
self = [super initWithFrame:frame];
if(self){
documentRef= docRef;
_pageNum= page;
self.backgroundColor= [UIColor whiteColor];
}
return self;
}
然后呢 因为是循环渲染绘制 需要重写 drawRect 重写此方法，执行重绘任务
drawRect调用是在Controller->loadView,，Controller->viewDidLoad 两方法之后调用的
- (void)drawRect:(CGRect)rect {
[self drawPDFIncontext:UIGraphicsGetCurrentContext()];//将当前的上下文环境传递 新建方法
}
好了 最重要的一部分要来了
- (void)drawPDFIncontext:(CGContextRef)context {
//调整图形的位置
//Quartz坐标系和UIView坐标系不一样所致，调整坐标系，使pdf正立CGContextTranslateCTM(context,0.0,self.frame.size.height);
//图形呈正立显示
CGContextScaleCTM(context,1.0, -1.0);
/获取指定页的pdf文档CGPDFPageRef pageRef =CGPDFDocumentGetPage(documentRef,_pageNum);
//记录当前绘制环境，防止多次绘画
CGContextSaveGState(context);
//创建一个仿射变换，该变换基于将PDF页的BOX映射到指定的矩形中。CGAffineTransform pdfTransForm =CGPDFPageGetDrawingTransform(pageRef,kCGPDFCropBox,self.bounds,0,true);
CGContextConcatCTM(context, pdfTransForm);
//将pdf绘制到上下文中CGContextDrawPDFPage(context, pageRef);
//将pdf保存CGContextRestoreGState(context);
}
好了 自定义的view 实现的方法就是这些了 然后回到vc页面去
主要是在.m里面的 viewDidLoad
下面 我要开始了哦
翻页我们可以想到很多 比如UIPageViewController UICollectionView等 这里我主要说的是UIPageViewController
@property (nonatomic,strong) UIPageViewController *pageVC;
@property (nonatomic,strong) NSMutableArray *pdfArr;
这个你们都懂吧
self.pdfArr = [NSMutableArray array];
NSDictionary *options = [NSDictionary dictionaryWithObject:[NSNumber numberWithInteger:UIPageViewControllerSpineLocationMin] forKey:UIPageViewControllerOptionSpineLocationKey];
self.pageVC = [[UIPageViewController alloc]initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal options:options];
_pageVC.view.frame = self.view.bounds;
_pageVC.delegate = self;
_pageVC.dataSource = self;
[self addChildViewController:_pageVC];
CGPDFDocumentRef pdfRef = [self pdfRefByDataByUrl:@"http://eb18036.ebenny.com/new_huasun_server/upload//pdf//1527047215118.pdf"];
size_t count = CGPDFDocumentGetNumberOfPages(pdfRef);//这个位置主要是获取pdf页码数；
for (int i = 0; i < count; i++) {
UIViewController *pdfVC = [[UIViewController alloc] init];
LLPDFView *pdfView = [[LLPDFView alloc]initWithFrame:self.view.bounds documentRef:pdfRef andPageNum:i+1];
[pdfVC.view addSubview:pdfView];
[_pdfArr addObject:pdfVC];
}
[_pageVC setViewControllers:[NSArray arrayWithObject:_pdfArr[0]] direction:UIPageViewControllerNavigationDirectionForward animated:YES completion:nil];
[self.view addSubview:_pageVC.view];
- (CGPDFDocumentRef)pdfRefByDataByUrl:(NSString *)aFileUrl {
NSURL*url = [NSURL URLWithString:aFileUrl];
CFURLRef refURL = (__bridge_retained CFURLRef)url;
CGPDFDocumentRef document =CGPDFDocumentCreateWithURL(refURL);
if(refURL){
CFRelease(refURL);
}
if(document) {
return document;//返回获取到的数据
}else{
return NULL; //如果没获取到数据，则返回NULL，当然，你可以在这里添加一些打印日志，方便你发现问题
}
}
- (UIViewController *)viewControllerAtIndex:(NSInteger)index
{
//Create a new view controller and pass suitable data.
if (([_pdfArr count] == 0 )|| (index > [_pdfArr count]) ) {
return nil;
}
NSLog(@"index = %ld",(long)index);
return (UIViewController *)_pdfArr[index];
}
- (NSUInteger) indexOfViewController:(UIViewController *)viewController
{
return [self.pdfArr indexOfObject:viewController];
}
- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController
{
NSUInteger index = [self indexOfViewController:(UIViewController *)viewController];
if (index == NSNotFound) {
return nil;
}
index++;
if (index == [_pdfArr count]){
return nil;
}
return [self viewControllerAtIndex:index];
}
- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController
{
NSUInteger index = [self indexOfViewController:(UIViewController *)viewController];
if ((index == 0 ) || (index == NSNotFound)){
return nil;
}
index--;
return [self viewControllerAtIndex:index];
}
