如何动态调整 UIScrollview 的大小

Question

我正在使用 UIScrollview 缩放图像..我的 UIScrollview 大小是固定的，所以每当我缩放图像时它就会被剪切..我想这样做，因为我缩放图像时 UIScrollview 也会增加高度和宽度根据图像缩放.. 任何建议将不胜感激......

Answer 1

这应该可行:-)

1. 制作 UIImage
2. 制作一个 UIImageView 来保存图像
3. 将 UIImageView 放入 UIScrollView
4. 将 UIScrollView 的 contentSize 设置为 UIImage 的大小
5. 记得返回viewForZoomingInScrollView中的UIimageView

把它放到你的 .h 文件中：

UIImageView *imageView;

@property (nonatomic, retain) UIImageView *imageView;

并且记得合成发布imageView

把它放在你想要滚动视图的地方：

UIImage *image = [UIImage imageNamed:@"myImage.jpg"];
imageView = [[UIImageView alloc] initWithImage:image];
[imageView setFrame:CGRectMake(0, 0, image.size.width, image.size.height)];
UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
[scrollView setMinimumZoomScale:0.5];
[scrollView setMaximumZoomScale:3.0];
[scrollView setContentSize:CGSizeMake(image.size.width, image.size.height)];
[scrollView setDelegate:self];
[scrollView addSubview:imageView];
[[self view] addSubview:scrollView];
[scrollView release];

添加 UIScrollView 委托方法

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
    return imageView;
}

更新：

我在添加上述解决方案时误解了这个问题。应该这样做:-)

kScrollViewAddSize 是一个常量，它定义了要添加到 UIScrollView 大小的数量。

在您的 .h 文件中，您应该添加以下内容：

UIImageView *imageView;
UIScrollView *scrollView;

记得合成并释放它们。

- (void)viewDidLoad
{
    [super viewDidLoad];

    UIImage *image = [UIImage imageNamed:@"apple.jpg"];
    imageView = [[UIImageView alloc] initWithImage:image];
    [imageView setFrame:CGRectMake(kScrollViewAddSize / 2, kScrollViewAddSize / 2, image.size.width, image.size.height)];
    int width = imageView.frame.size.width + kScrollViewAddSize;
    int height = imageView.frame.size.height + kScrollViewAddSize;
    scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake((self.view.frame.size.width - width) / 2, (self.view.frame.size.height - height) / 2, width, height)];
    [scrollView setMinimumZoomScale:0.5];
    [scrollView setMaximumZoomScale:3.0];
    [scrollView setBackgroundColor:[UIColor redColor]];
    [scrollView setContentSize:CGSizeMake(image.size.width, image.size.height)];
    [scrollView setDelegate:self];
    [scrollView addSubview:imageView];
    [[self view] addSubview:scrollView];
}

- (void)scrollViewDidZoom:(UIScrollView *)_scrollView {
    int width = imageView.frame.size.width + kScrollViewAddSize;
    int height = imageView.frame.size.height + kScrollViewAddSize;
    [scrollView setFrame:CGRectMake((self.view.frame.size.width - width) / 2, (self.view.frame.size.height - height) / 2, imageView.frame.size.width + kScrollViewAddSize, imageView.frame.size.height + kScrollViewAddSize)];
}

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)_scrollView {
    return imageView;
}

在viewDidLoad 中添加要创建 UIScrollView 的部分并添加两个委托方法。