- (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.模擬器運(yùn)行, 查看xcode錯誤日志

程序執(zhí)行后會立即崩潰, 打開xcode系統(tǒng)日志可以看到以下錯誤信息

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)

通過xcode日志可以看到是數(shù)組訪問越界, 發(fā)生越界的方式名為print

針對這個demo我們當(dāng)然很清楚是剛才列的array[1]發(fā)生越界, 但對于一個完整的程序如何查看是在哪個地方發(fā)生越界的呢?

這個時候我們可以利用xcode的Show the breakpoint navigator功能, 點(diǎn)加號選擇add exception breakpoint

這個時候我們在執(zhí)行程序, xcode執(zhí)行會自動停在要發(fā)生crash的代碼段

Demo#2.真機(jī)調(diào)試, 查看xcode錯誤日志
如果有添加exeception point, 程序會自動停到打印array[1]那一行. 如果沒有添加則程序會crash, xcode會出現(xiàn)以下錯誤日志

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)

通過錯誤信息我們只能看到是有發(fā)生數(shù)組訪問越界, 如果有添加exeception breakpoint則會自動停在發(fā)生error的代碼行.

Demo#3. 真機(jī)運(yùn)行, 查看device系統(tǒng)日志

xcode停止運(yùn)行這個crashdemo, 選擇xcode window - devices, 選擇手機(jī) - view device logs

然后在手機(jī)上運(yùn)行crashdemo, 在device logs中按時間排序查看最新的log就能看到crashdemo的crash log

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

這些在開發(fā)階段都能很簡便的實現(xiàn), 但是當(dāng)app發(fā)布出去后用戶發(fā)生crash呢? 一般用戶只能反饋在做什么的時候發(fā)生crash

然后我們在去做嘗試是否能遇到, 不過這樣效率不高而且一般很難復(fù)現(xiàn)到用戶的crash

Bugly的出現(xiàn)解決的這個問題

Bugly SDK在當(dāng)程序崩潰時, 會自動將錯誤信息發(fā)送到服務(wù)器方便開發(fā)人員查看分析

那么如何使用Bugly?

首先先到https://bugly.qq.com/v2/注冊賬號, 并注冊app下載SDK包

將Bugly.framework拖拽到工程中, 記得勾選copy if needed.

然后添加libz.tbd / libstdc++.tbd / Security.framework / SystemConfiguration.framework到工程中

delegate.m中注冊

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { 
    [Bugly startWithAppId:@"此處替換為你的AppId"]; 
    return YES; 
 }

這樣當(dāng)程序發(fā)生崩潰時, 崩潰信息會自動發(fā)送到服務(wù)器登錄你的bugly賬號就能查看到了