具有多个相同对象的 CALayer 数组
我是否正在尝试创建一款不断向用户发射障碍物的游戏？我有一个 NSMutableArray，所以我可以作为一个组访问所有障碍。这是我的代码：
CALayer *obstacle = [[[CALayer alloc] init] autorelease];
UIImage *obstacleImage = [UIImage imageNamed:@"Obstacle.png"];
obstacle.contents = (id)obstacleImage.CGImage;
obstacle.bounds = CGRectMake(0, 0, starImage.size.width/2, starImage.size.width/2);
int xPosition = (arc4random()%(360-0))+0;
obstacle.position = CGPointMake(xPosition, 20);
[self.view.layer addSublayer:obstacle];
[self.obstacleArray addObject:obstacle];
我的问题是：如何访问该数组中的对象？我希望能够访问最新的对象，以便可以为其设置动画。我浏览过 NSMutableArray Class Reference ，但仍然找不到任何东西。我已经尝试过这个：
NSLog(@"%d",[obstacleArray indexOfObject:obstacle]);
但它返回的只是：0。是否有一个我没有看到的简单解决方案？预先感谢您的任何回复。
Am I trying to create a game where an obstacle is constantly fired at the user. I have an NSMutableArray so I can access all the obstacles as a group. Here is my code:
CALayer *obstacle = [[[CALayer alloc] init] autorelease];
UIImage *obstacleImage = [UIImage imageNamed:@"Obstacle.png"];
obstacle.contents = (id)obstacleImage.CGImage;
obstacle.bounds = CGRectMake(0, 0, starImage.size.width/2, starImage.size.width/2);
int xPosition = (arc4random()%(360-0))+0;
obstacle.position = CGPointMake(xPosition, 20);
[self.view.layer addSublayer:obstacle];
[self.obstacleArray addObject:obstacle];
My questions is: How would I access the objects in this array? I want to be able to access the latest object so I can animate it. I have looked through the NSMutableArray Class Reference , but still can't find anything. I have tried this:
NSLog(@"%d",[obstacleArray indexOfObject:obstacle]);
But all it returns is: 0. Is there an easy solution to this problem that I'm just not seeing? Thanks in advance for any responses.
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使用
[obstacleArray lastObject]或[obstacleArray objectAtIndex:[obstacleArray count]-1]获取最后一个对象。您可以在 NSArray 类参考中找到它。 （因为它是 NSMutableArray 的父类）Use
[obstacleArray lastObject]or[obstacleArray objectAtIndex:[obstacleArray count]-1]to get the last Object. You can find that in the NSArray Class Reference. (Since it's the parent class of NSMutableArray)