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

Posted 2020-06-08

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://[e-mail]?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);