Question

你好吗？

我想在每次调用计时器时创建一个新的实例变量，例如

        numberofObjects += 1;
    i = numberofObjects;

    UIImageView *Object[i] = [[UIImageView alloc] initWithFrame:CGRectMake(randomx,0,36 ,36)];        
    UIImage *imag = [UIImage imageNamed:@"ball.png"];
    [Object[i] setImage:imag];
    [self.view addSubview:Object[i]];

有办法做到这一点吗？

任何意见将不胜感激。

Answer 1

这并不难做到。我假设您将只有最大数量的UIImageViews，因为这会增加很多开销，如果允许永久继续，您可能会遇到问题。在.h文件中，

@interface viewController : UIViewController {
  int numberAdded;
  NSTimer * timer;
  UIImageView * currentImageView;
  NSMutableArray * arrayOfImageViews;
}

- (void)addNewImageView;

@end

在.m文件中：

#define MaxImageViews 20 // This is changeable!

@implementation viewController

- (void)viewDidLoad; {
  [super viewDidLoad];
  numberAdded = 0;
  arrayOfImageViews = [[NSMutableArray alloc] init];
  timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(addNewImageView) userInfo:nil repeats:YES];
}

- (void)addNewImageView; {
  if(numberAdded >= MaxImageViews){
    [timer invalidate];
    timer = nil;
    return;
  }
  int randomX = arc4random() % 320; // Gives value from 0 - 319.
  int randomY = arc4random() % 480; // Gives value from 0 - 479.
  UIImageView * imageView = [[UIImageView alloc] initWithFrame:CGRectMake(randomX, randomY, 36, 36)];
  imageView.image = [UIImage imageNamed:@"ball.png"];
  [self.view addSubview:imageView];
  [arrayOfImageViews addObject:imageView];
  [currentImageView release];
      currentImageView = imageView;
    }

- (void)dealloc; {
  [currentImageView release];
  [arrayOfImageViews release];
  [super dealloc];
}

@end

这应该跟踪数组arrayOfImageViews中的所有imageView，并且您可以通过调用[arrayOfImageViews objectAtIndex:i]来访问第i个imageView。 currentImageView指针跟踪添加的最新UIImageView。希望有所帮助！

Answer 2

将图像视图的指针存储在NSMutableArray对象中。

如何在每次调用计时器时使用不同的实例变量创建新的UIImageView

2 个答案: