目前,我正在将硬件解码Obj-C代码转换为Swift版本。(代码8,Swift 3)。
我不知道如何设置字典来在屏幕上设置输出选项,也不知道如何使用它。
以下代码在Obj-C项目中运行良好:
// set some values of the sample buffer's attachments
CFArrayRef attachments = CMSampleBufferGetSampleAttachmentsArray(sampleBuffer, YES);
CFMutableDictionaryRef dict = (CFMutableDictionaryRef)CFArrayGetValueAtIndex(attachments, 0);
CFDictionarySetValue(dict, kCMSampleAttachmentKey_DisplayImmediately, kCFBooleanTrue);
我尝试了以下Swift代码,但出现了运行时错误:
// i got run-time error
let attachments = CMSampleBufferGetSampleAttachmentsArray(sampleBuffer!, true)
let dict = unsafeBitCast(attachments, to: CFMutableDictionary.self)
CFDictionarySetValue(dict, unsafeBitCast(kCMSampleAttachmentKey_DisplayImmediately, to: UnsafeRawPointer.self), unsafeBitCast(kCFBooleanTrue, to: UnsafeRawPointer.self))
将
CFString
转换为UnsafeRawPointer
是否错误?还是使用CFDictionarySetValue
方法是错误的?这是我的错误日志。
2016-11-24 16:50:44.458 MyApp[35288:3519253] -[__NSSingleObjectArrayI __setObject:forKey:]: unrecognized selector sent to instance 0x6000002045a0
2016-11-24 16:50:44.466 MyApp[35288:3519253] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSSingleObjectArrayI __setObject:forKey:]: unrecognized selector sent to instance 0x6000002045a0'
*** First throw call stack:
(
0 CoreFoundation 0x000000010b02734b __exceptionPreprocess + 171
1 libobjc.A.dylib 0x000000010a0e421e objc_exception_throw + 48
2 CoreFoundation 0x000000010b096f34 -[NSObject(NSObject) doesNotRecognizeSelector:] + 132
3 CoreFoundation 0x000000010afacc15 ___forwarding___ + 1013
4 CoreFoundation 0x000000010afac798 _CF_forwarding_prep_0 + 120
5 MyApp 0x000000010937ac7a _TFC14MyApp16ViewerController21receivedRawVideoFramefT5frameGSaVs5UInt8_4withVs5Int32_T_ + 4890
6 MyApp 0x000000010937d8e2 _TFC14MyApp16ViewerController12MainCallBackfTVs5Int3212callbackCodeS1_8argumentGSqSv_7argSizeS1__T_ + 4242
7 MyApp 0x000000010937daed _TToFC14MyApp16ViewerController12MainCallBackfTVs5Int3212callbackCodeS1_8argumentGSqSv_7argSizeS1__T_ + 61
8 MyApp 0x000000010937dd56 _TTDFC14MyApp16ViewerController12MainCallBackfTVs5Int3212callbackCodeS1_8argumentGSqSv_7argSizeS1__T_ + 70
9 MyApp 0x000000010937dcfe _TTWC14MyApp16ViewerControllerS_18IJCallbackProtocolS_FS1_12MainCallBackfTVs5Int3212callbackCodeS2_8argumentGSqSv_7argSizeS2__T_ + 62
10 MyApp 0x00000001093b22b2 _TFC14MyApp11AppDelegate19MainCallBack_StreamfTVs5Int32S1_GSqSv_S1__T_ + 258
11 MyApp 0x00000001093d26d3 _TFZFC14MyApp19IJStreamCoreWrapper6AttachFTSv2ipSS4portSi_T_U_FTVs5Int32S1_GSqSv_S1_GSqSv__T_ + 355
12 MyApp 0x00000001093d2719 _TToFZFC14MyApp19IJStreamCoreWrapper6AttachFTSv2ipSS4portSi_T_U_FTVs5Int32S1_GSqSv_S1_GSqSv__T_ + 9
13 MyApp 0x00000001093ee176 _ZL8CallbackPN14CStreamManager9Session_TEiPvi + 70
14 MyApp 0x00000001093f09d3 _Z25StreamManagerThread_VideoPv + 3155
15 libsystem_pthread.dylib 0x000000010e494aab _pthread_body + 180
16 libsystem_pthread.dylib 0x000000010e4949f7 _pthread_body + 0
17 libsystem_pthread.dylib 0x000000010e494221 thread_start + 13
)
libc++abi.dylib: terminating with uncaught exception of type NSException
最佳答案
在第一个代码片段中,有一个对CFArrayGetValueAtIndex
的调用,它返回一个传递给CFDictionarySetValue
的字典。
在第二个代码片段中,您不会调用CFArrayGetValueAtIndex
。只需将数组传递到CFDictionarySetValue
。因为数组不是字典,所以会出现致命错误。
关于swift - 如何快速使用CFDictionarySetValue?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/40780419/