Question

我修改了Apple的Scrolling示例，以获取从CoreData个对象中引用的文件创建的一系列图像。我可以很好地添加图像，但我还想以编程方式为每个图像添加UIButton。图像数量取决于CoreData个对象的数量，因此我无法使用IB。

有人可以帮我解决一下如何最好地实现这个目标吗？

以下是抓取CoreData商店中图片的代码：

NSUInteger i;
for (i = 1; i <= kNumImages; i++)
{
    Sentence *testSentence = [[managedObjectContext executeFetchRequest:request error:&error] objectAtIndex:i];

    NSArray *paths       = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
    NSString *imageName = [[paths objectAtIndex:0] stringByAppendingPathComponent:[testSentence image]];
    NSLog(@"imageName: %@", imageName);

    UIImage *image = [[UIImage alloc] initWithContentsOfFile:imageName];
    NSLog(@"image: %@", image);

    UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
    NSLog(@"imageView: %@", imageView);

    [imageView setContentMode:UIViewContentModeScaleAspectFit];
    [imageView setBackgroundColor:[UIColor blackColor]];

    // setup each frame to a default height and width, it will be properly placed when we call "updateScrollList"
    CGRect rect = imageView.frame;
    rect.size.height = kScrollObjHeight;
    rect.size.width = kScrollObjWidth;
    imageView.frame = rect;
    imageView.tag = i;  // tag our images for later use when we place them in serial fashion
    [scrollView1 addSubview:imageView];

    [image release];
    [imageView release];
}

[self layoutScrollImages];  // now place the photos in serial layout within the scrollview

这是在scrollview中放置图像的代码：

- (void)layoutScrollImages
{
UIImageView *view = nil;
NSArray *subviews = [scrollView1 subviews];

// reposition all image subviews in a horizontal serial fashion
CGFloat curXLoc = 0;
for (view in subviews)
{
    if ([view isKindOfClass:[UIImageView class]] && view.tag > 0)
    {
        CGRect frame = view.frame;
        frame.origin = CGPointMake(curXLoc, 0);
        view.frame = frame;

        curXLoc += (kScrollObjWidth);
    }
}

// set the content size so it can be scrollable
[scrollView1 setContentSize:CGSizeMake((kNumImages * kScrollObjWidth), [scrollView1 bounds].size.height)];
}

Answer 1

不确定我理解你的问题。你不能这样做吗？

...
 imageView.frame = rect;
UIButton *aButton = [UIButton buttonWithType:UIButtonTypeCustom];
aButton.frame = imageView.frame;
[aButton addTarget:self action:@selector(whatever:) forControlEvents:UIControlEventTouchUpInside];
[imageView addSubview:aButton];

Answer 2

我在创建图库时遇到了同样的问题，我添加到每个缩略图的按钮都不会响应TouchUpInside事件。

我能够通过创建一个自定义UIView子类来保持每个单独的图像并在该子类中实现touchesBegan：withEvent：和touchesEnded：withEvent：来实现它。

请参阅UIScrollView programming guide了解示例代码。

如果您不允许在UIScrollView上进行缩放，则可以通过假设每个触摸结束都是单个触摸事件来简化代码。

以编程方式将UIButtons和UIImages添加到UIScrollview

2 个答案: