异常捕获拒绝闪退 让应用从容的崩溃UncaughtExceptionHandler

虽然大家都不愿意看到程序崩溃，但可能崩溃是每个应用必须面对的现实，既然崩溃已经发生，无法阻挡了，那我们就让它崩也崩得淡定点吧。

IOS SDK中提供了一个现成的函数 NSSetUncaughtExceptionHandler 用来做异常处理，但功能非常有限，而引起崩溃的大多数原因如：内存访问错误，重复释放等错误就无能为力了，因为这种错误它抛出的是Signal，所以必须要专门做Signal处理。首先定义一个UncaughtExceptionHandler类，代码如下：

#import <Foundation/Foundation.h>

#import <UIKit/UIKit.h>

@interface UncaughtExceptionHandler : NSObject

{

BOOL dismissed;

}

+(void) InstallUncaughtExceptionHandler;

@end

//利用 NSSetUncaughtExceptionHandler，当程序异常退出的时候，可以先进行处理，然后做一些自定义的动作，比如下面一段代码，就是网上有人写的，直接在发生异常时给某人发送邮件，</span>

void UncaughtExceptionHandlers (NSException *exception);

#import "UncaughtExceptionHandler.h"

#include <libkern/OSAtomic.h>

#include <execinfo.h>

NSString * const UncaughtExceptionHandlerSignalExceptionName = @"UncaughtExceptionHandlerSignalExceptionName";

NSString * const UncaughtExceptionHandlerSignalKey = @"UncaughtExceptionHandlerSignalKey";

NSString * const UncaughtExceptionHandlerAddressesKey = @"UncaughtExceptionHandlerAddressesKey";

volatile int32_t UncaughtExceptionCount = 0;

const int32_t UncaughtExceptionMaximum = 10;

const NSInteger UncaughtExceptionHandlerSkipAddressCount = 4;

const NSInteger UncaughtExceptionHandlerReportAddressCount = 5;

NSString* getAppInfo()

{

NSString *appInfo = [NSString stringWithFormat:@"App : %@ %@(%@)\nDevice : %@\nOS Version : %@ %@\n",

[[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleDisplayName"],

[[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleShortVersionString"],

[[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleVersion"],

[UIDevice currentDevice].model,

[UIDevice currentDevice].systemName,

[UIDevice currentDevice].systemVersion];

//     [UIDevice currentDevice].uniqueIdentifier];

NSLog(@"Crash!!!! %@", appInfo);

return appInfo;

}

void MySignalHandler(int signal)

{

int32_t exceptionCount = OSAtomicIncrement32(&UncaughtExceptionCount);

if (exceptionCount > UncaughtExceptionMaximum)

{

return;

}

if(signal==11)

{//比较坑爹的是 我遇到的一个问题只有iPhone5出现问题 但是我这边测试的没有iPhone5 无法直接log  可能是内存不足 果然 删除几个应用就可以了 所以加了这句

UIAlertView * tip2 = [[UIAlertView alloc]initWithTitle:@"可能原因:key" message:@"内存不足" delegate:nil cancelButtonTitle:@"ok" otherButtonTitles:nil];

[tip2 show];

[tip2 release];

}

NSMutableDictionary *userInfo = [NSMutableDictionary dictionaryWithObject:[NSNumber numberWithInt:signal] forKey:UncaughtExceptionHandlerSignalKey];

NSArray *callStack = [UncaughtExceptionHandler backtrace];

[userInfo setObject:callStack forKey:UncaughtExceptionHandlerAddressesKey];

[[[[UncaughtExceptionHandler alloc] init] autorelease]

performSelectorOnMainThread:@selector(handleException:)

withObject:

[NSException

exceptionWithName:UncaughtExceptionHandlerSignalExceptionName

reason:

[NSString stringWithFormat:

NSLocalizedString(@"Signal %d was raised.\n"

@"%@", nil),

signal, getAppInfo()]

userInfo:

[NSDictionary

dictionaryWithObject:[NSNumber numberWithInt:signal]

forKey:UncaughtExceptionHandlerSignalKey]]

waitUntilDone:YES];

}

@implementation UncaughtExceptionHandler

+(void) InstallUncaughtExceptionHandler

{

signal(SIGABRT, MySignalHandler);

signal(SIGILL, MySignalHandler);

signal(SIGSEGV, MySignalHandler);

signal(SIGFPE, MySignalHandler);

signal(SIGBUS, MySignalHandler);

signal(SIGPIPE, MySignalHandler);

}

+ (NSArray *)backtrace

{

void* callstack[128];

int frames = backtrace(callstack, 128);

char **strs = backtrace_symbols(callstack, frames);

int i;

NSMutableArray *backtrace = [NSMutableArray arrayWithCapacity:frames];

for (

i = UncaughtExceptionHandlerSkipAddressCount;

i < UncaughtExceptionHandlerSkipAddressCount +

UncaughtExceptionHandlerReportAddressCount;

i++)

{

[backtrace addObject:[NSString stringWithUTF8String:strs[i]]];

}

free(strs);

return backtrace;

}

- (void)alertView:(UIAlertView *)anAlertView clickedButtonAtIndex:(NSInteger)anIndex

{

if (anIndex == 0)

{

dismissed = YES;

}

}

- (void)handleException:(NSException *)exception

{

UIAlertView *alert =

[[[UIAlertView alloc]

initWithTitle:NSLocalizedString(@"Unhandled exception", nil)

message:[NSString stringWithFormat:NSLocalizedString(

@"You can try to continue but the application may be unstable.\n"

@"%@\n%@", nil),

[exception reason],

[[exception userInfo] objectForKey:UncaughtExceptionHandlerAddressesKey]]

delegate:self

cancelButtonTitle:NSLocalizedString(@"Quit", nil)

otherButtonTitles:NSLocalizedString(@"Continue", nil), nil]

autorelease];

[alert show];

CFRunLoopRef runLoop = CFRunLoopGetCurrent();

CFArrayRef allModes = CFRunLoopCopyAllModes(runLoop);

while (!dismissed)

{

for (NSString *mode in (NSArray *)allModes)

{

CFRunLoopRunInMode((CFStringRef)mode, 0.001, false);

}

}

CFRelease(allModes);

NSSetUncaughtExceptionHandler(NULL);

signal(SIGABRT, SIG_DFL);

signal(SIGILL, SIG_DFL);

signal(SIGSEGV, SIG_DFL);

signal(SIGFPE, SIG_DFL);

signal(SIGBUS, SIG_DFL);

signal(SIGPIPE, SIG_DFL);

if ([[exception name] isEqual:UncaughtExceptionHandlerSignalExceptionName])

{

kill(getpid(), [[[exception userInfo] objectForKey:UncaughtExceptionHandlerSignalKey] intValue]);

}

else

{

[exception raise];

}

}

void UncaughtExceptionHandlers (NSException *exception) {

NSArray *arr = [exception callStackSymbols];

NSString *reason = [exception reason];

NSString *name = [exception name];

NSString *urlStr = [NSString stringWithFormat:@"mailto://1140454645@qq.com?subject=bug报告&body=感谢您的配合!<br><br><br>"

"错误详情:<br>%@<br>--------------------------<br>%@<br>---------------------<br>%@",

name,reason,[arr componentsJoinedByString:@"<br>"]];

NSURL *url = [NSURL URLWithString:[urlStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];

[[UIApplication sharedApplication] openURL:url];

//或者直接用代码，输入这个崩溃信息，以便在console中进一步分析错误原因

NSLog(@"1heqin, CRASH: %@", exception);

NSLog(@"heqin, Stack Trace: %@", [exception callStackSymbols]);

}

@end

然后在delegate文件里面- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions函数里面

[UncaughtExceptionHandler InstallUncaughtExceptionHandler];

NSSetUncaughtExceptionHandler (&UncaughtExceptionHandlers);