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我创建了一个对象数组。这些对象有一个公共变量correct。当我关闭 xcode 优化时，我的项目中的所有内容都运行良好，但是当我设置任何类型的优化时，事情就会出错。我第一次创建这些对象中的一个correct时，从另一个类访问时，变量总是返回 false。但随后创建此类对象会返回正确的值correct。这是我的代码和问题的片段。

。H

@interface ShellQuestionAnswer : UIView
{
    ...

    @public
    bool correct;
    ...
}

.m

-(void)setLetter:(NSString*)letter forAnswer:(XMLNode*)answer withResponse:(XMLNode*)response
{
    ...
    correct = [[[answer attributes] valueForKey:@"Correct"] isEqualToString:@"true"];
    //Putting NSLog here shows "correct" to be true
}

以及使用这个对象的类：

-(void)addQuestion:(XMLNode*) rootNode ID:(NSString*)ID
{
...
     answer1 = [[ShellQuestionAnswer alloc] initWithFrame:CGRectMake(0, currentY, textContainer.frame.size.width, 50)]; 
        [answer1 setLetter:@"A" forAnswer:[answerstextArray objectAtIndex:0] withResponse:[responsestextArray objectAtIndex:0]];
        currentY += answer1.frame.size.height + QUESTION_SEPARATION;
        if(!answerObjects)
        {
            answerObjects = [[NSMutableArray alloc] init];
        }
        else
        {
            [answerObjects removeAllObjects];
        }
        [answerObjects addObject:answer1];

        answer2 = [[ShellQuestionAnswer alloc] initWithFrame:CGRectMake(0, currentY, textContainer.frame.size.width, 50)];
        [answer2 setLetter:@"B" forAnswer:[answerstextArray objectAtIndex:1] withResponse:[responsestextArray objectAtIndex:1]];
        currentY += answer2.frame.size.height + QUESTION_SEPARATION;
        [answerObjects addObject:answer2];

        [textContainer addSubview:answer1];
        [answer1 setUserInteractionEnabled:YES];
        [textContainer addSubview:answer2];
        [answer2 setUserInteractionEnabled:YES];
        if([answerstextArray count] > 2)
        {
            answer3 = [[ShellQuestionAnswer alloc] initWithFrame:CGRectMake(0, currentY, textContainer.frame.size.width,50)];
            [answer3 setLetter:@"C" forAnswer:[answerstextArray objectAtIndex:2] withResponse:[responsestextArray objectAtIndex:2]];
            [textContainer addSubview:answer3];
            currentY += answer3.frame.size.height + QUESTION_SEPARATION;
            [answerObjects addObject:answer3];
            [answer3 setUserInteractionEnabled:YES];
        }
        if([answerstextArray count] > 3)
        {
            answer4 = [[ShellQuestionAnswer alloc] initWithFrame:CGRectMake(0, currentY, textContainer.frame.size.width, 50)];
            [answer4 setLetter:@"D" forAnswer:[answerstextArray objectAtIndex:3] withResponse:[responsestextArray objectAtIndex:3]];
            [textContainer addSubview:answer4];
            currentY += answer4.frame.size.height + QUESTION_SEPARATION;
            [answerObjects addObject:answer4];
            [answer4 setUserInteractionEnabled:YES];
        }

        [textContainer setNeedsDisplay]; 
        for(ShellQuestionAnswer *answer in answerObjects)
        {
            if(answer->correct)  //<-- always returns false the first time I run this function
            {
                if(!self.correctAnswer)
                {
                    self.correctAnswer = [[NSMutableArray alloc] init];
                }
                [self.correctAnswer addObject:answer];
            }
        }
}

我已经记录了所有内容，但不明白为什么在answer->correct对象外部返回 false，但在answer对象内部，变量correct实际上是 true。这仅在优化开启（任何模式）并且仅在使用此类的第一个实例时发生。

如果我将correct变量更改为属性而不是公共类成员变量，则问题不再存在。我对这个解决方案很好，但我不明白为什么会发生这种情况。这个问题可能出现在我的代码中的任何其他类中，直到客户在第一次运行时抱怨随机怪癖，我才知道在哪里。这是我无法接受的。有人对为什么优化会弄乱我的代码有任何想法吗？

编辑：为了更清楚，这是我正在使用的测试用例。一种有效，一种无效（以上述方式）。

在职的：

@interface ShellQuestionAnswer : UIView
{
    ...

    @public
    //bool correct;
    ...
}
@property (nonatomic, assign) bool correct;

不工作：

@interface ShellQuestionAnswer : UIView
{
    ...

    @public
    bool correct;
    ...
}

这些是为获得工作集而更改的唯一行（除了answer->correct更改answer.correct为属性案例的 for 循环内部）。

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