如何防止“[__NSArrayM objectAtIndex:]:索引 10 超出范围 [0 .. 9]'”

How can I prevent "[__NSArrayM objectAtIndex:]: index 10 beyond bounds [0 .. 9]'"

我有一个使用循环计数器的按钮操作方法,循环运行 0 到 9,然后触发另一个事件。我遇到的问题是,如果按钮被按下超过 10 次,它会抛出 [__NSArrayM objectAtIndex:]: index 10 beyond bounds [0 .. 9]' error。我知道这意味着按钮操作的启动次数比阵列配置的次数多,我想知道的是如何防止错误发生?因此,如果该操作启动超过 10 次,应用程序不会因 [__NSArrayM objectAtIndex:]: index 10 beyond bounds [0 .. 9] 而崩溃。任何帮助都会很棒。

这是循环计数器:

-(void) gameLoop {

if (loopCounter < 10){
    revealArray = [[NSMutableArray alloc] initWithObjects:@"1", @"2", @"3", @"4", @"5", @"6", @"7", @"8", nil];
    cover1.alpha = 1.0;
    cover2.alpha = 1.0;
    cover3.alpha = 1.0;
    cover4.alpha = 1.0;
    cover5.alpha = 1.0;
    cover6.alpha = 1.0;
    cover7.alpha = 1.0;
    cover8.alpha = 1.0;
    coreView.alpha = 1.0;

NSDictionary *question = nil;

question = [questionsArray objectAtIndex:loopCounter];

questionImage.image = [UIImage imageNamed:[question objectForKey:@"imageNames"]];
[self getAnswers];
}
else {
    //NSLog(@"finished");

   [self animateResults];
}

}

此代码创建数组:

-(void) getAnswers {

Tribes *tribes = [[Tribes alloc]init];
[tribes createArray];
answersArray = [[tribes optionsArray]mutableCopy];

NSDictionary *question = nil;
question = [questionsArray objectAtIndex:0];

 if ([[answersArray objectAtIndex:0] isEqualToString:[question objectForKey:@"answers"]] || [[answersArray objectAtIndex:1] isEqualToString:[question objectForKey:@"answers"]]){
   [self getAnswers];
}

else {
    [self answerLabelMethod];
    NSLog(@"%@", answersArray);

    questionTimer =[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(revealImage) userInfo:nil repeats:YES ];

}
}

我发现断点在这个方法中:

- (void) answerMethod:(int)answerBtn {

if (answerBtn == random) {
    //NSLog(@"correct!");
    int maxScore = 10000;
    int userScore = maxScore - (questionTimerCounter*1000);
    NSLog(@"%d", userScore);
    runningScore = runningScore + userScore;
    NSLog(@"%d" , runningScore);

    NSMutableDictionary *question = nil;
    //either at this point 
    question = [[questionsArray objectAtIndex:loopCounter]mutableCopy];
    //
    [question setObject:[NSNumber numberWithBool:YES] forKey:@"correct"];
    [question setObject:[NSNumber numberWithInt:userScore] forKey:@"score"];
    [questionsArray replaceObjectAtIndex:loopCounter withObject:question];
        }
else {

    NSMutableDictionary *question = nil;
    //or this point
    question = [[questionsArray objectAtIndex:loopCounter]mutableCopy];
    //
    [question setObject:[NSNumber numberWithBool:NO] forKey:@"correct"];
    [question setObject:[NSNumber numberWithInt:0] forKey:@"score"];
    [questionsArray replaceObjectAtIndex:loopCounter withObject:question];

}

GameInProgress = NO;

loopCounter++;
[self revealAnswer];

}

你试图在我认为超出数组范围的索引处获取对象。在需要时放置 breakpoint 并检查数组大小。添加 exception breakpoint 以检查您的应用崩溃的位置。

我猜你的 "question array" 没有那么大的容量来访问第 11 个元素,因为它只包含 10 个元素(0 到 9)

所以在这一行附近放置一个断点,你会得到一些解决问题的线索 问题 = [questionsArray objectAtIndex:loopCounter];