分段故障的来源在哪里: 11？

Question

请帮帮忙，这是我在这里的三个错误之一，我只是找不到它们在哪里:我知道它们与我的结构有关，但我不知道如何找到它们……下面是代码的第一部分，其中有一个错误：

-(BOOL)detectCollisionBetweenEntityAtIndex:(int)index1 andEntityAtIndex:(int)index2
{
  if ((([entityArray objectAtIndex:index1].entityX >= [entityArray objectAtIndex:index2].entityX) && ([entityArray objectAtIndex:index1].entityX <= ([entityArray objectAtIndex:index2].entityX + [entityArray objectAtIndex:index2].entityWidth)) && ([entityArray objectAtIndex:index1].entityY >= [entityArray objectAtIndex:index2].entityY) && ([entityArray objectAtIndex:index1].entityY <= ([entityArray objectAtIndex:index2].entityY + [entityArray objectAtIndex:index2].entityLength))) || (([entityArray objectAtIndex:index1].entityX + [entityArray objectAtIndex:index1].entityWidth >= [entityArray objectAtIndex:index2].entityX) && ([entityArray objectAtIndex:index1].entityX + [entityArray objectAtIndex:index1].entityWidth <= ([entityArray objectAtIndex:index2].entityX + [entityArray objectAtIndex:index2].entityWidth)) && ([entityArray objectAtIndex:index1].entityY + [entityArray objectAtIndex:index1].entityLength  >= [entityArray objectAtIndex:index2].entityY) && ([entityArray objectAtIndex:index1].entityY + [entityArray objectAtIndex:index1].entityLength <= ([entityArray objectAtIndex:index2].entityY+ [entityArray objectAtIndex:index2].entityLength))))
  {
    return TRUE;
  }
  else
  {
    return FALSE;
  }
}

entityArray是一个NSMutable数组，填充了我创建的一个结构的实例：

struct Entity
{
  int entityX;
  int entityY;
  int entityLength;
  int entityWidth;
  int entityType;
  int entitySpeed;
  bool isDead;
};

Answer 1

大致是这样的：

    -(BOOL)detectCollisionBetweenEntityAtIndex:(int)index1 andEntityAtIndex:(int)index2
    {
    bool hasDetected = false;
      if (...)
      {
        hasDetected = TRUE;
      }
        else
      {
        hasDetected = FALSE;
      }
        return hasDetected ;
      }

应该把它弄清楚！

Answer 2

NSMutableArray只能存储Objective-C对象，而不能存储C结构。将实体包装在NSValue对象中，以将它们存储在数组中：

Entity entity;
// populate entity...

NSValue *value = [NSValue valueWithBytes:&entity objCType:@encode(struct Entity)];
[array addObject:value];

要获取返回值，请使用-[NSValue getValue:]，如下所示：

NSValue *value = [array objectAtIndex:index];
Entity entity;
[value getValue:&entity];