UIGraphicsBeginPDFPage()在64位设备上随机崩溃(CGPDFSecurityManagerCreateDecryptor())

Question

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.

在Bacisally,该方法打开一个现有的PDF,它创建一个新的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pdf中.

当该方法尝试为文档创建新的pdf页面时(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; 打电话.

它只发生在一些PDF文件中,而不是全部,只发生在64位设备上.

这是显示CGPDFSecurityManagerCreateDecryptor()调用的堆栈跟踪,我无法找到它的作用.

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 ()

如果你对这次崩溃有任何想法,那么你的帮助将会非常感激,有一天我会尽力解决这个问题并且想知道这不是UIKit的错误......

谢谢

Answer 1

我仅使用以下代码在 64 台设备上的 CGPDFSecurityManagerCreateDecryptor 方法上发生崩溃：

CGPDFDocumentRelease(pdf);
CGDataProviderRelease(provider);
UIGraphicsEndPDFContext();

结束上下文时将调用 CGPDFSecurityManagerCreateDecryptor。当我在发布文档和提供程序之前结束上下文时，崩溃消失了。

UIGraphicsEndPDFContext();
CGPDFDocumentRelease(pdf);
CGDataProviderRelease(provider);