ios异常（crash）输出

//这里是主要的异常处理例子
void uncaughtExceptionHandler(NSException *exception)
{
    // 异常的堆栈信息
    NSArray * stackArray  = [exception callStackSymbols];
    // 出现异常的原因
    NSString * reason  = [exception reason];
    // 异常名称
    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];
    //保存到本地  —  当然你可以在下次启动的时候，上传这个log
    [exceptionInfo writeToFile:[NSString stringWithFormat:@"%@/Documents/error.log",NSHomeDirectory()]  atomically:YES encoding:NSUTF8StringEncoding error:nil];
    
}  

- (void) printError {
    NSError *error;
    
    NSString *textFileContents = [NSString stringWithContentsOfFile:[NSString stringWithFormat:@"%@/Documents/error.log",NSHomeDirectory()] encoding: NSUTF8StringEncoding error: & error];
    
    if (textFileContents == nil) {
        NSLog(@"Error reading text file. %@", [error localizedFailureReason]);
    }
    NSArray *lines = [textFileContents componentsSeparatedByString:@"\n"];
    NSLog(@"%@", textFileContents);
    NSLog(@"Number of lines in the file:%d", [lines count] );
}

// 程序启动的时候直接调用
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // 捕获异常
    NSSetUncaughtExceptionHandler(&uncaughtExceptionHandler);
    
    self.window = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];
    [self.window makeKeyAndVisible];
    self.window.rootViewController = [[ViewController alloc]init];
    
    [[CatchCrash alloc] printError];
    
    return YES;
}