【IOS】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:[NSExceptionexceptionWithName:UncaughtExceptionHandlerSignalExceptionNamereason:[NSString stringWithFormat:NSLocalizedString(@"Signal %d was raised.\n"@"%@", nil),signal, getAppInfo()]userInfo:[NSDictionarydictionaryWithObject:[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:selfcancelButtonTitle: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);