我有一个崩溃报告（至少我希望如此，因为我从XCode Organizer获取此日志时已经有了象征意义）
Incident Identifier: F4324555-0916-4E32-82EF-3272917367BB
Beta Identifier: 80811904-A512-48A1-9593-D386703A62F0
Hardware Model: iPhone7,2
Process: SelfieSuperStarz [596]
Path: /private/var/containers/Bundle/Application/BFA0D82B-274B-400B-8F84-52A1D7369C51/SelfieSuperStarz.app/SelfieSuperStarz
Identifier: com.PuckerUp.PuckerUp
Version: 21 (1.31)
Beta: YES
Code Type: ARM-64 (Native)
Role: Foreground
Parent Process: launchd [1]
Coalition: com.PuckerUp.PuckerUp [434]
Date/Time: 2017-07-29 20:06:11.7394 -0400
Launch Time: 2017-07-29 19:34:39.7433 -0400
OS Version: iPhone OS 10.3.2 (14F89)
Report Version: 104
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Exception Note: EXC_CORPSE_NOTIFY
Triggered by Thread: 0
Last Exception Backtrace:
0 CoreFoundation 0x18bebafe0 __exceptionPreprocess + 124 (NSException.m:165)
1 libobjc.A.dylib 0x18a91c538 objc_exception_throw + 56 (objc-exception.mm:521)
2 CoreFoundation 0x18be26eb4 -[__NSArray0 objectAtIndex:] + 108 (CFArray.c:69)
3 SelfieSuperStarz 0x10007b708 specialized _ArrayBuffer._getElementSlowPath(Int) -> AnyObject + 116
4 SelfieSuperStarz 0x10007ea40 specialized Merger.merge(completion : () -> (), assets : [Asset]) -> () + 1444 (Merger.swift:0)
5 SelfieSuperStarz 0x100071f3c specialized AssetView.finish(UIButton) -> () + 520 (Merger.swift:0)
6 SelfieSuperStarz 0x1000712d0 @objc AssetView.finish(UIButton) -> () + 40 (AssetView.swift:0)
7 UIKit 0x192021010 -[UIApplication sendAction:to:from:forEvent:] + 96 (UIApplication.m:4580)
8 UIKit 0x192020f90 -[UIControl sendAction:to:forEvent:] + 80 (UIControl.m:609)
9 UIKit 0x19200b504 -[UIControl _sendActionsForEvents:withEvent:] + 440 (UIControl.m:694)
10 UIKit 0x192020874 -[UIControl touchesEnded:withEvent:] + 576 (UIControl.m:446)
11 UIKit 0x192020390 -[UIWindow _sendTouchesForEvent:] + 2480 (UIWindow.m:2122)
12 UIKit 0x19201b728 -[UIWindow sendEvent:] + 3192 (UIWindow.m:2292)
13 UIKit 0x191fec33c -[UIApplication sendEvent:] + 340 (UIApplication.m:10778)
14 UIKit 0x1927e6014 __dispatchPreprocessedEventFromEventQueue + 2400 (UIEventDispatcher.m:1448)
15 UIKit 0x1927e0770 __handleEventQueue + 4268 (UIEventDispatcher.m:1671)
16 UIKit 0x1927e0b9c __handleHIDEventFetcherDrain + 148 (UIEventDispatcher.m:1706)
17 CoreFoundation 0x18be6942c __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 24 (CFRunLoop.c:1943)
18 CoreFoundation 0x18be68d9c __CFRunLoopDoSources0 + 540 (CFRunLoop.c:1989)
19 CoreFoundation 0x18be669a8 __CFRunLoopRun + 744 (CFRunLoop.c:2821)
20 CoreFoundation 0x18bd96da4 CFRunLoopRunSpecific + 424 (CFRunLoop.c:3113)
21 GraphicsServices 0x18d800074 GSEventRunModal + 100 (GSEvent.c:2245)
22 UIKit 0x192051058 UIApplicationMain + 208 (UIApplication.m:4089)
23 SelfieSuperStarz 0x10002e990 main + 56 (AppDelegate.swift:16)
24 libdyld.dylib 0x18ada559c start + 4
正如你所看到的那样，我在第0行的班级合并中说道。这是不可能的，你可以假设。我不确定如何解释什么是专门的手段或为什么@objc在那里。
3 SelfieSuperStarz 0x10007b708 specialized _ArrayBuffer._getElementSlowPath(Int) -> AnyObject + 116
4 SelfieSuperStarz 0x10007ea40 specialized Merger.merge(completion : () -> (), assets : [Asset]) -> () + 1444 (Merger.swift:0)
5 SelfieSuperStarz 0x100071f3c specialized AssetView.finish(UIButton) -> () + 520 (Merger.swift:0)
6 SelfieSuperStarz 0x1000712d0 @objc AssetView.finish(UIButton) -> () + 40 (AssetView.swift:0)
只是不确定错误发生在哪里，因为该行显示为Merger：0并且我不确定那些标题（special / objc）是什么意思，如果他们告诉我任何事情。
这是我在Merger中的合并功能。我使用各种循环和计算不透明度并确定事情，但我在位置检查nil。
func merge(completion:@escaping () -> Void, assets:[Asset]) {
self.setupAI()
let assets = assets.sorted(by: { $0.layer.zPosition < $1.layer.zPosition })
if let firstAsset = controller.firstAsset {
let mixComposition = AVMutableComposition()
let firstTrack = mixComposition.addMutableTrack(withMediaType: AVMediaTypeVideo,
preferredTrackID: Int32(kCMPersistentTrackID_Invalid))
do {
try firstTrack.insertTimeRange(CMTimeRangeMake(kCMTimeZero, self.controller.realDuration),
of: firstAsset.tracks(withMediaType: AVMediaTypeVideo)[0],
at: kCMTimeZero)
} catch _ {
print("Failed to load first track")
}
let documentDirectory = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
var myTracks:[AVMutableCompositionTrack] = []
var ranges:[ClosedRange<CMTime>] = []
for asset in assets {
let secondTrack = mixComposition.addMutableTrack(withMediaType: AVMediaTypeVideo,
preferredTrackID: Int32(kCMPersistentTrackID_Invalid))
secondTrack.preferredTransform = asset.asset.preferredTransform
do {
try secondTrack.insertTimeRange(CMTimeRangeMake(kCMTimeZero, asset.endTime-asset.beginTime),
of: asset.asset.tracks(withMediaType: AVMediaTypeVideo)[0],
at: CMTime(seconds: CMTimeGetSeconds(asset.beginTime), preferredTimescale: 600000))
} catch _ {
print("Failed to load second track")
}
if(ranges.count == 0) {
ranges.append(asset.beginTime...asset.endTime)
}
else {
var none = true
for range in ranges {
let start = range.contains(asset.beginTime)
let end = range.contains(asset.endTime)
var connection = false
var nothing = false
//This range is completely encompassed (begin and end inside)
if(start && end) {
//Don't add to the rnge
none = false
nothing = true
}
//Begin is in range (right side)
else if(start && !end) {
connection = true
none = false
}
//End is in range (left side)
else if(!start && end) {
connection = true
none = false
}
var connected = false
//It connects 2 different timess
if(connection) {
for range2 in ranges {
if(range != range2) {
if(start && range2.contains(asset.endTime)) {
let index = ranges.index(of: range)
if(index != nil) {
ranges.remove(at: index!)
ranges.append(range.lowerBound...range2.upperBound)
connected = true
break
}
}
else if(end && range2.contains(asset.beginTime)) {
let index = ranges.index(of: range)
if(index != nil) {
ranges.remove(at: index!)
ranges.append(range.lowerBound...range2.upperBound)
connected = true
break
}
}
}
}
}
if(!connected && !none && !nothing) {
if(start) {
let index = ranges.index(of: range)
if(index != nil) {
ranges.remove(at: index!)
ranges.append(range.lowerBound...asset.endTime)
}
}
else if(end) {
let index = ranges.index(of: range)
if(index != nil) {
ranges.remove(at: index!)
ranges.append(asset.beginTime...asset.endTime)
}
}
}
}
if(none) {
ranges.append(asset.beginTime...asset.endTime)
}
}
myTracks.append(secondTrack)
}
for range in ranges {
print(CMTimeGetSeconds(range.lowerBound), CMTimeGetSeconds(range.upperBound))
}
for assets in self.controller.assets {
print(CMTimeGetSeconds(assets.beginTime), CMTimeGetSeconds(assets.endTime))
}
if let loadedAudioAsset = self.controller.audioAsset {
let audioTrack = mixComposition.addMutableTrack(withMediaType: AVMediaTypeAudio, preferredTrackID: 0)
do {
try audioTrack.insertTimeRange(CMTimeRangeMake(kCMTimeZero, self.controller.realDuration),
of: loadedAudioAsset.tracks(withMediaType: AVMediaTypeAudio)[0] ,
at: kCMTimeZero)
} catch _ {
print("Failed to load Audio track")
}
}
let mainInstruction = AVMutableVideoCompositionInstruction()
mainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, self.controller.realDuration)
// 2.2
let firstInstruction = self.videoCompositionInstructionForTrack(firstTrack, firstAsset)
var instructions:[AVMutableVideoCompositionLayerInstruction] = []
var counter:Int = 0
for tracks in myTracks {
let secondInstruction = self.videoCompositionInstructionForTrack(tracks, assets[counter].asset, type:true)
let index = myTracks.index(of: tracks)
//This should never be nil, but if it is, it might cause opacity's to go out of whack for that specific track. Only reason I can think of why I am crashing in this method.
if(index != nil) {
if(index! < assets.count-1) {
for i in (counter+1...assets.count-1) {
if(assets[counter].endTime > assets[i].endTime) {
secondInstruction.setOpacity(1.0, at: assets[i].endTime)
secondInstruction.setOpacity(0.0, at: assets[counter].endTime)
print("Bigger")
break
}
}
}
if(index! > 0) {
for i in (0...counter).reversed() {
if(assets[counter].endTime < assets[i].endTime) {
secondInstruction.setOpacity(0.0, at: assets[counter].endTime)
print("Smaller")
break
}
}
}
if(counter < myTracks.count-1) {
if(assets[counter].layer.zPosition <= assets[counter+1].layer.zPosition) {
secondInstruction.setOpacity(0.0, at: assets[counter+1].beginTime)
}
else {
secondInstruction.setOpacity(0.0, at: assets[counter].endTime)
}
}
instructions.append(secondInstruction)
counter += 1
}
}
for range in ranges {
firstInstruction.setOpacity(0.0, at: range.lowerBound)
firstInstruction.setOpacity(1.0, at: range.upperBound)
}
// 2.3
mainInstruction.layerInstructions = [firstInstruction] + instructions
let imageLayer = CALayer()
let image = UIImage(named: "Watermark")
imageLayer.contents = image!.cgImage
let ratio = (firstAsset.tracks(withMediaType: AVMediaTypeVideo)[0].naturalSize.width/image!.size.width)/2
let rect = CGRect(x: image!.size.width*ratio, y: 0, width: image!.size.width*ratio, height: image!.size.height*ratio)
imageLayer.frame = rect
imageLayer.backgroundColor = UIColor.clear.cgColor
imageLayer.opacity = 0.75
let videoLayer = CALayer()
videoLayer.frame = CGRect(x: 0, y: 0, width: firstAsset.tracks(withMediaType: AVMediaTypeVideo)[0].naturalSize.width, height: firstAsset.tracks(withMediaType: AVMediaTypeVideo)[0].naturalSize.height)
let parentlayer = CALayer()
parentlayer.frame = CGRect(x: 0, y: 0, width: image!.size.width*ratio, height: image!.size.height*ratio)
parentlayer.addSublayer(videoLayer)
parentlayer.addSublayer(imageLayer)
let mainComposition = AVMutableVideoComposition()
mainComposition.instructions = [mainInstruction]
mainComposition.frameDuration = CMTimeMake(1, 30)
mainComposition.renderSize = self.controller.firstAsset!.tracks(withMediaType: AVMediaTypeVideo)[0].naturalSize
mainComposition.animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayer: videoLayer, in: parentlayer)
答案 0 :(得分：0)
很明显，方法＆＃34; Merger.merge＆＃34;访问不存在的元素。调试器将显示它的位置。
我猜测某些线程正在修改一些背后的数组，以便在某些时候有效的索引变得无效。并且＆＃34;对于范围中的范围2＆＃34;当你以后修改＆＃34;范围＆＃34;是在惹麻烦。
答案 1 :(得分：0)
我猜这个问题是由第129行引起的，考虑到+1444偏移和数组访问。您是否尝试过没有音频的视频，例如未经音频许可拍摄的视频？假设在我的应用程序中拍摄的视频总是有音轨，我遇到了一个出界的崩溃。您会惊讶于用户将哪些视频输入到您的应用中。我甚至让一个用户使用从他们的电话相册中选择的flv视频来崩溃我的应用程序。
（我不确定这是否适用于Swift） 也可以使用调试器在Xcode中找到该行。首先，使用与发布版本相同的优化设置运行应用程序。然后在函数中断开不同的行以检查汇编代码。 How to see assembly code in xcode 6。您可能需要滚动到顶部以仔细检查函数名称和偏移的含义。
_ArrayBuffer._getElementSlowPath是私有API中的一个类，由下划线前缀表示。你可能找不到任何关于它的可信和/或官方消息来源。
崩溃日志中的不完整可能是由Swift（其背后的工具）的错误/不成熟引起的。欢迎来到最流行和最流行的语言之一。即使在工作条件下，Swift也会为生成的代码提供第0行，其中代码与源代码的任何有意义的部分都不对应。但事实并非如此。