当app出现崩溃, 研发阶段一般可以通过以下方式来跟踪crash信息
#1.模拟器运行, 查看xcode错误日志
#2.真机调试, 查看xcode错误日志
#3.真机运行, 查看device系统日志
下面举例说明, 先写一段会Crash的代码crashdemo:
代码语言：javascript复制- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[self performSelector:@selector(print) withObject:nil afterDelay:5];
}
- (void)print {
NSArray *array = @[];
NSLog(@"%@", array[1]);
}Demo#1.模拟器运行, 查看xcode错误日志
程序执行后会立即崩溃, 打开xcode系统日志可以看到以下错误信息
代码语言：javascript复制2016-10-29 12:13:29.015 CrashDemo[37842:7436441] *** Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArray0 objectAtIndex:]: index 1 beyond bounds for empty NSArray'
*** First throw call stack:
(
0 CoreFoundation 0x00b7ba84 __exceptionPreprocess 180
1 libobjc.A.dylib 0x00642e02 objc_exception_throw 50
2 CoreFoundation 0x00b22390 __CFArrayGetTypeID_block_invoke 0
3 CoreFoundation 0x00ac07f8 -[NSArray objectAtIndexedSubscript:] 40
4 CrashDemo 0x000877b7 -[ViewController print] 87
5 Foundation 0x00250d71 __NSFireDelayedPerform 442
6 CoreFoundation 0x00acd576 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ 22
7 CoreFoundation 0x00accf72 __CFRunLoopDoTimer 1250
8 CoreFoundation 0x00a8b25a __CFRunLoopRun 2202
9 CoreFoundation 0x00a8a706 CFRunLoopRunSpecific 470
10 CoreFoundation 0x00a8a51b CFRunLoopRunInMode 123
11 GraphicsServices 0x041e4664 GSEventRunModal 192
12 GraphicsServices 0x041e44a1 GSEventRun 104
13 UIKit 0x00f0c1eb UIApplicationMain 160
14 CrashDemo 0x00087bba main 138
15 libdyld.dylib 0x03189a21 start 1
)
libc abi.dylib: terminating with uncaught exception of type NSException
(lldb) 通过xcode日志可以看到是数组访问越界, 发生越界的方式名为print 针对这个demo我们当然很清楚是刚才列的array[1]发生越界, 但对于一个完整的程序如何查看是在哪个地方发生越界的呢? 这个时候我们可以利用xcode的Show the breakpoint navigator功能, 点加号选择add exception breakpoint 这个时候我们在执行程序, xcode执行会自动停在要发生crash的代码段
Demo#2.真机调试, 查看xcode错误日志
如果有添加exeception point, 程序会自动停到打印array[1]那一行. 如果没有添加则程序会crash, xcode会出现以下错误日志
代码语言：javascript复制2016-10-29 12:15:53.561 CrashDemo[1062:316582] *** Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArray0 objectAtIndex:]: index 1 beyond bounds for empty NSArray'
*** First throw call stack:
(0x211b398b 0x2094ee17 0x211433e7 0xc5a3b 0x219d1ad5 0x211765ff 0x21176231 0x2117407d 0x210c32e9 0x210c30d5 0x226b3ac9 0x257880b9 0xc5c99 0x20d6b873)
libc abi.dylib: terminating with uncaught exception of type NSException
(lldb)通过错误信息我们只能看到是有发生数组访问越界, 如果有添加exeception breakpoint则会自动停在发生error的代码行.
Demo#3. 真机运行, 查看device系统日志
xcode停止运行这个crashdemo, 选择xcode window - devices, 选择手机 - view device logs
然后在手机上运行crashdemo, 在device logs中按时间排序查看最新的log就能看到crashdemo的crash log
代码语言：javascript复制Incident Identifier: 9A4C52F0-B0D7-42C9-A7CB-D4D3321D00D5
CrashReporter Key: 90f4d3621773443794fa73f506fd6bdef49fc269
Hardware Model: iPhone4,1
Process: CrashDemo [1074]
Path: /private/var/containers/Bundle/Application/1307034E-9C2B-451F-ACD9-04C97DEC047B/CrashDemo.app/CrashDemo
Identifier: PEGA.CrashDemo
Version: 1 (1.0)
Code Type: ARM (Native)
Parent Process: launchd [1]
Date/Time: 2016-10-29 12:21:49.49 0800
Launch Time: 2016-10-29 12:21:43.43 0800
OS Version: iOS 9.3.1 (13E238)
Report Version: 104
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Exception Note: EXC_CORPSE_NOTIFY
Triggered by Thread: 0
Filtered syslog:
None found
Last Exception Backtrace:
0 CoreFoundation 0x211b3986 __exceptionPreprocess 122
1 libobjc.A.dylib 0x2094ee12 objc_exception_throw 34
2 CoreFoundation 0x211433e2 -[__NSArray0 objectAtIndex:] 110
3 CrashDemo 0x000e6a36 0xe0000 27190
4 Foundation 0x219d1ad0 __NSFireDelayedPerform 464
5 CoreFoundation 0x211765fa 这些在开发阶段都能很简便的实现, 但是当app发布出去后用户发生crash呢? 一般用户只能反馈在做什么的时候发生crash
然后我们在去做尝试是否能遇到, 不过这样效率不高而且一般很难复现到用户的crash
Bugly的出现解决的这个问题
Bugly SDK在当程序崩溃时, 会自动将错误信息发送到服务器方便开发人员查看分析
那么如何使用Bugly?
首先先到https://bugly.qq.com/v2/注册账号, 并注册app下载SDK包
将Bugly.framework拖拽到工程中, 记得勾选copy if needed.
然后添加libz.tbd / libstdc .tbd / Security.framework / SystemConfiguration.framework到工程中
delegate.m中注册
代码语言：javascript复制- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
[Bugly startWithAppId:@"此处替换为你的AppId"];
return YES;
}这样当程序发生崩溃时, 崩溃信息会自动发送到服务器登录你的bugly账号就能查看到了
