之前部落格介紹啦一種異常捕獲後彈窗提示使用者的方法，《iOS崩潰 捕獲異常處理》，下面提供另外一種異常捕獲的方法。原理一致，但實現略有不同。可供參考。

1、在didFinishLaunchingWithOptions 中，註冊訊息處理函式，處理崩潰資訊，寫入本地。

 //註冊訊息處理函式的處理方法,處理崩潰資訊,寫入本地
    NSSetUncaughtExceptionHandler(&uncaughtExceptionHandler);

2、將CrashManager.h、 CrashManager.m 拖拽到工程中，具體實現如下：
CrashManager.h：

@interface
 
 CrashManager : NSObject
/** 捕捉Crash */
void uncaughtExceptionHandler(NSException *exception);

+ (id)defaultManager;//單例

/** 移除Crash的log日誌 */
- (void)clearCrashLog;

/** 是否有log日誌 */
- (BOOL)isCrashLog;

/** crash log日誌 */
- (NSString *)crashLogContent;

@end

CrashManager.m 中核心函式如下：

void uncaughtExceptionHandler(NSException
 
 *exception){
    // 異常的堆疊資訊
    NSArray *stackArray = [exception callStackSymbols];
    // 出現異常的原因
    NSString *reason = [exception reason];
    // 異常名稱
    NSString *name = [exception name];
    NSString *exceptionInfo = [NSString stringWithFormat:@"Exception reason：%@\nException name：%@\nException stack：%@"
 
,name, reason, stackArray];
    NSLog(@"%@", exceptionInfo);
    NSMutableArray *tmpArr = [NSMutableArray arrayWithArray:stackArray];
    [tmpArr insertObject:reason atIndex:0];
    NSString *crashLocalPath = [NSString stringWithFormat:@"%@/Documents/microFinanceCrashError.txt",NSHomeDirectory()];
    NSLog(@"crash LocalPath :%@ ",crashLocalPath);
    //儲存到本地  --  當然你可以在下次啟動的時候，上傳這個log
    [exceptionInfo writeToFile:crashLocalPath  atomically:YES encoding:NSUTF8StringEncoding error:nil]；
}

+ (id)defaultManager{
    @synchronized(self){
        static dispatch_once_t pred;
        dispatch_once(&pred, ^{
            crashManager = [[self alloc] init];
        });
    }
    return crashManager;
}


#pragma mark -移除Crash的log日誌
- (void)clearCrashLog{
    NSFileManager *fileManager = [[NSFileManager alloc]init];
    [fileManager removeItemAtPath:LocalCrashLogPath error:nil];
}

#pragma mark - 是否有log日誌
- (BOOL)isCrashLog{
    NSError *error;
    NSString *textFileContents = [NSString stringWithContentsOfFile:LocalCrashLogPath encoding:NSUTF8StringEncoding error:&error];
    if ([self checkConvertNull:textFileContents]) {//無log日誌
        return NO;
    }else{
        return YES;
    }
}


#pragma mark -crash log日誌
- (NSString *)crashLogContent{
    NSError *error;
    NSString *textFileContents = [NSString stringWithContentsOfFile:LocalCrashLogPath encoding:NSUTF8StringEncoding error:&error];
    if ([self checkConvertNull:textFileContents]) {//無log日誌
        return @"";
    }else{
        return textFileContents;
    }
}

#pragma mark - 檢查是否有空字元
- (BOOL)checkConvertNull:(NSString *)object{
    if ([object isEqual:[NSNull null]] || [object isKindOfClass:[NSNull class]] ||object==nil || [object isEqualToString:@""]) {
        return YES;
    }else{
        return NO;
    }
}

3、在ViewController中，做如下測試案例：

- (void)viewDidLoad {
    [super viewDidLoad];
    CrashManager *crashManager = [CrashManager defaultManager];

    if ([crashManager isCrashLog]) {//Crash日誌

        NSString *crashString = [crashManager crashLogContent];//Crash日誌內容
        NSLog(@"crashString = %@",crashString);//
    }
//    [crashManager clearCrashLog];//清除Crash日誌
    //Crash測試
    UIButton *crashBtn = [UIButton buttonWithType:UIButtonTypeCustom];
    crashBtn.frame = CGRectMake(self.view.frame.size.width/2 - 50, 200, 100, 40);
    crashBtn.backgroundColor = [UIColor redColor];
    [crashBtn addTarget:self action:@selector(crashTest) forControlEvents:UIControlEventTouchUpInside];
    [crashBtn setTitle:@"Crash" forState:UIControlStateNormal];
    [crashBtn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
    [self.view addSubview:crashBtn];

}

-(void)crashTest{

    NSString *crashString = nil;
    NSDictionary *params = [NSDictionary dictionary];
    params = @{@"crashTest":crashString,
               };
}