问题描述
我正在努力使用pdf导出方法，该方法运行得很好，直到我将应用程序移植到arm64架构。
I'm struggling with a pdf export method that's was running just fine until I ported the app to the arm64 achitecture.
Bacisally，该方法打开现有PDF ，它会创建一个新的pdf文件，并在添加更多内容页面之前将第一个pdf的内容绘制到新创建的文件中。
Bacisally, the method opens an existing PDF, it creates a new pdf file, and draws the content of the first pdf into the newly created one before adding more content pages.
当方法尝试创建新内容页面时pdf页面到文档（在第一个pdf集成到新的pdf之后）应用程序崩溃，并在UIGraphicsBeginPDFPage（）上发出EXC_BAD_ACCESS警告;电话。
When the method tries to create a new pdf page to the document (after the first pdf was integrated to the new pdf) the app crashes with a EXC_BAD_ACCESS warning on UIGraphicsBeginPDFPage(); call .
它只发生在一些PDF文件上，而不是全部，只发生在64位设备上。
It only happens with some PDF files, not all and only on 64 bit devices.
这里是显示CGPDFSecurityManagerCreateDecryptor（）调用的stacktrace，我无法找到它的作用。
Here's the stacktrace which shows the CGPDFSecurityManagerCreateDecryptor () call which I couldn't find what it does.
Thread 14Queue : NSOperationQueue 0x14f6dd3a0 :: NSOperation 0x17504a470 (serial)
#0 0x00000001838aeee4 in CGPDFSecurityManagerCreateDecryptor ()
#1 0x00000001838d1004 in pdf_filter_chain_create ()
#2 0x0000000183831e00 in CGPDFStreamCreateFilterChain ()
#3 0x000000018383226c in chain_get_bytes ()
#4 0x0000000183b5e0ac in unpackImageRow ()
#5 0x0000000183b5dfd4 in PDFImageEmitData ()
#6 0x0000000183b5f684 in emit_image ()
#7 0x0000000183b5ef9c in PDFImageEmitDefinition ()
#8 0x0000000183464584 in __CFSetApplyFunction_block_invoke ()
#9 0x00000001834643bc in CFBasicHashApply ()
#10 0x00000001834642e4 in CFSetApplyFunction ()
#11 0x0000000183b5fa9c in PDFImageSetEmitDefinitions ()
#12 0x0000000183b590c0 in emit_page_resources(PDFDocument*) ()
#13 0x0000000183b5904c in PDFDocumentEndPage ()
#14 0x0000000183b57cf0 in pdf_EndPage ()
#15 0x0000000187fda904 in UIGraphicsBeginPDFPageWithInfo ()
#16 0x00000001002093e8 in -[ExportTools renderPdfContentToContext:forPlanVersion:]
#17 0x00000001001fba60 in -[ExportTools generatePdfReportWithOptions:]
#18 0x00000001000f7eb4 in -[DetailViewController generatePdfAndShowModalOpenWithAppWithOptions:]
#19 0x00000001835883c0 in __invoking___ ()
#20 0x0000000183486138 in -[NSInvocation invoke] ()
#21 0x000000018443ba20 in -[NSInvocationOperation main] ()
#22 0x000000018437c61c in -[__NSOperationInternal _start:] ()
#23 0x000000018443e26c in __NSOQSchedule_f ()
#24 0x000000010105cdf0 in _dispatch_client_callout ()
#25 0x0000000101067854 in _dispatch_queue_drain ()
#26 0x0000000101060120 in _dispatch_queue_invoke ()
#27 0x000000010106975c in _dispatch_root_queue_drain ()
#28 0x000000010106af18 in _dispatch_worker_thread3 ()
#29 0x00000001945012e4 in _pthread_wqthread ()
如果您对此次崩溃有任何疑问，我们将非常感谢您的帮助，有一天会尝试一切来解决这个问题并且想知道它是不是UIKit错误......
If you have any idea about this crash, your help would be greatly appreciated, been one day trying everything to fix this and beggening to wonder if it's not a UIKit bug...
谢谢
推荐答案
我在64台设备上的CGPDFSecurityManagerCreateDecryptor方法崩溃时只使用以下代码：
I had a crash on the CGPDFSecurityManagerCreateDecryptor method on 64-devices only with the following code:
CGPDFDocumentRelease(pdf);
CGDataProviderRelease(provider);
UIGraphicsEndPDFContext();
结束上下文时会调用CGPDFSecurityManagerCreateDecryptor。当我在释放文档和提供者之前结束上下文时，崩溃就消失了。
CGPDFSecurityManagerCreateDecryptor would get called when ending the context. The crash went away when I ended the context BEFORE releasing the document and provider.
UIGraphicsEndPDFContext();
CGPDFDocumentRelease(pdf);
CGDataProviderRelease(provider);
这篇关于UIGraphicsBeginPDFPage（）在64位设备上随机崩溃（CGPDFSecurityManagerCreateDecryptor（））的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！