Question

在AViewController中有initwithPDFAtPath

-(id)initWithPDFAtPath:(NSString *)path {

NSURL *pdfUrl = [NSURL fileURLWithPath:path];
thePDF = CGPDFDocumentCreateWithURL((__bridge CFURLRef)pdfUrl);
totalPages = (int)CGPDFDocumentGetNumberOfPages(thePDF);

self = [super initWithNibName:nil bundle:nil];
return self;

 }

尝试使用viewDidLoad方法在BViewController中打开pdf文件

 - (void)viewDidLoad {

[super viewDidLoad];

//modelArray holds the page numbers

modelArray = [[NSMutableArray alloc] init];

for (int index = 1; index <= totalPages; index++) {

[modelArray addObject:[NSString stringWithFormat:@"%i", index]];

}
thePageViewController = [[UIPageViewController alloc] initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl navigationOrientation: UIPageViewControllerNavigationOrientationHorizontal options:nil];

thePageViewController.delegate = self;
thePageViewController.dataSource = self;

thePageViewController.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
NSString *path = [[NSBundle mainBundle] pathForResource:@"pages" ofType:@"pdf"];

NSURL *pdfurl = [NSURL fileURLWithPath:path];
PDFDocument = CGPDFDocumentCreateWithURL((__bridge CFURLRef)pdfurl);
AViewController = [[AViewController alloc] initWithPDFAtPath:path];
aViewController.page = [modelArray objectAtIndex:0];
NSArray *viewControllers = [NSArray arrayWithObject:aViewController];

}

当我执行它时，它会以空数组消息崩溃。由于未捕获的异常'NSRangeException'而终止应用程序，原因：' * - [__ NSArrayM objectAtIndex：]：索引0超出空数组的边界'

编辑：

AViewController有一个PDFScrollview

   - (void)viewDidLoad
  {
[super viewDidLoad];

// Create our PDFScrollView and add it to the view controller.
CGPDFPageRef PDFPage = CGPDFDocumentGetPage(thePDF, [_page intValue]);

pdfScrollView = [[PDFScrollView alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, 925)];
[pdfScrollView setPDFPage:PDFPage];

[self.view addSubview:pdfScrollView];
  }

Answer 1

从我在此处看到的情况看，您似乎在modelArray的号码之前初始化totalPages，因为这仅在initWithPDFAtPath中设置。虽然我认为您可以（并且应该）重新组织代码，以便只有一个视图控制器必须管理页码，但您可以通过移动行来解决问题

AViewController *aViewController = [[AViewController alloc] initWithPDFAtPath:path];

在您初始化modelArray之前的位置。

希望这有帮助！

Answer 2

听起来我totalPages无法初始化BViewController。

同样不确定如何存储它，就像在AViewController中调用super init之前对此变量进行初始化一样，这可能导致丢失此值。

为了解决这个问题，我认为你需要做几件事。

首先在AViewContoller中将init方法改为：

-(id)initWithPDFAtPath:(NSString *)path {

    self = [super initWithNibName:nil bundle:nil];
    if (self) {
        NSURL *pdfUrl = [NSURL fileURLWithPath:path];
        _thePDF = CGPDFDocumentCreateWithURL((__bridge CFURLRef)pdfUrl);
        _totalPages = (int)CGPDFDocumentGetNumberOfPages(thePDF);
    }

    return self;
 }

并将totalPages存储在参数中。

比你需要做的BViewController

- (void)viewDidLoad {

   [super viewDidLoad];

//modelArray holds the page numbers

thePageViewController = [[UIPageViewController alloc] initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl navigationOrientation: UIPageViewControllerNavigationOrientationHorizontal options:nil];

thePageViewController.delegate = self;
thePageViewController.dataSource = self;

thePageViewController.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
NSString *path = [[NSBundle mainBundle] pathForResource:@"pages" ofType:@"pdf"];

NSURL *pdfurl = [NSURL fileURLWithPath:path];
PDFDocument = CGPDFDocumentCreateWithURL((__bridge CFURLRef)pdfurl);
AViewController = [[AViewController alloc] initWithPDFAtPath:path];

modelArray = [[NSMutableArray alloc] init];

if (aViewController.totalPages > 0) {
   for (int index = 1; index <= aViewController.totalPages; index++) {

     [modelArray addObject:[NSString stringWithFormat:@"%i", index]];

       }

       aViewController.page = [modelArray objectAtIndex:0];
   }

        NSArray *viewControllers = [NSArray arrayWithObject:aViewController];
    }

但实际上这似乎是所有控制器架构的一些明显问题。

应用程序崩溃，错误消息为空数组

2 个答案: