Question

好吧，所以我总共有5个自定义图像。下面是我需要将每个图像设置为的值：

Image1 = 1
Image2 = 2
Image3 = 3
Image4 = 4
Image5 = 5

我需要为这些分配值，因为我想让xcode随机地将它们放在视图上，直到它达到50的值。所以我假设我需要某种循环来累加值直到达到50？

如何为这些图像赋值，因为它在尝试为UIImage分配int值时会显示警告。另外，在旁边注意我会使用什么方法将图像随机放置在视图上而不重叠？

感谢您的帮助！

Answer 1

您的应用会将UIImageView而非UIImage放置在视图上。与所有UIView子类一样，UIImageView具有NSInteger tag属性，但如果我正确理解了问题，我认为您也不需要。

// add count randomly selected images to random positions on self.view
// (assumes self is a kind of UIViewController)
- (void)placeRandomImages:(NSInteger)count {

    for (NSInteger i=0; i<count; ++i) {
        UIImage *image = [self randomImage];
        UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
        imageView.frame = [self randomFrameForImage:image];
        [self.view addSubview:imageView];

        // add a tag here, if you want, but I'm not sure what for
        // imageView.tag = i;
    }
}

// answer a random image from the app's bundle
// assumes the images are named image-x where x = 0..4
- (UIImage *)randomImage {

    NSInteger imageNumber = arc4random() % 5;
    NSString *imageName = [NSString stringWithFormat:@"image-%d", imageNumber];
    return [UIImage imageNamed:imageName];
}

// answer a random position for the passed image, keeping it inside the view bounds
- (CGRect)randomFrameForImage:(UIImage *)image {

    CGFloat imageWidth = image.width;
    CGFloat imageHeight = image.height;

    CGFloat maxX = CGRectGetMaxX(self.view.bounds) - imageWidth;
    CGFloat maxY = CGRectGetMaxY(self.view.bounds) - imageHeight;

    // random location, but always inside my view bounds
    CGFloat x = arc4random() % (NSInteger)maxX;
    CGFloat y = arc4random() % (NSInteger)maxY;

    return CGRectMake(x,y,imageWidth,imageHeight);
}

Answer 2

如果想要分配任意整数值，我会在UIImageView上使用tag属性。

 NSInteger currentTag = 50;
 while (currentTag > 0) {
        UIImageView *imageView = [UIImageView alloc initWithImage:image];
         imageView.tag = currentTag;
         [self.view addSubView:imageView];
         currentTag--;
   }

Answer 3

将图像放入NSArray，然后从NSHipster：

如何从NSArray中选择随机元素

使用arc4random_uniform（3）生成非空数组范围内的随机数。

if ([array count] > 0) {
  id obj = array[arc4random_uniform([array count])];
}

如何为图像指定值

3 个答案: