[英]How can I dynamically adjust contentInset in scrollViewDidZoom? I initially set contentInset of UIImageView in UIScrollview
I'm on a project that makes an custom 'Move and Scale' Controller
of UIImagePickerController
. 我正在开发一个项目,它可以自定义
UIImagePickerController
'Move and Scale' Controller
。 (controller when appear if imagePickerController.allowsEditing=YES
) (如果
imagePickerController.allowsEditing=YES
,则显示控制器)
I want to crop an UIImage
in the crop rectangular like the picture below. 我想在裁剪矩形
crop an UIImage
,如下图所示。
And I made some code to set contentInset
. 我做了一些代码来设置
contentInset
。
self.selectedImageView.backgroundColor = [UIColor redColor];
CGRect cropRect = [SKPhotoCropFrameView getCropRectFromOrientation:self.photoCropOrientation];
CGRect aspectFitRect = AVMakeRectWithAspectRatioInsideRect(self.selectedImageView.image.size, self.selectedImageView.frame);
CGFloat difference = fabsf(cropRect.size.height - aspectFitRect.size.height);
self.contentInset = UIEdgeInsetsMake(difference/2, 0, difference/2 + 20, 0); // 20 is status bar height
and here is the result. 这是结果。
Black region is contentInset area. 黑色区域是contentInset区域。
However, if I pinch this scrollView to zoom in, something happen. 但是,如果我捏这个scrollView进行放大,就会发生一些事情。
I think I have to do something on 我想我必须做些什么
- (void)scrollViewDidZoom:(UIScrollView *)scrollView
to adjust contentInset dynamically. 动态调整contentInset。 How can I do this?
我怎样才能做到这一点? Please give me some help :)
请给我一些帮助:)
I hoped someone answered this question, I'm sad because it's not. 我希望有人回答这个问题,我很难过,因为事实并非如此。
But thank God, I solved this. 但是感谢上帝,我解决了这个问题。
in 在
- (void)scrollViewDidZoom:(UIScrollView *)scrollView
adjust contentInset dynamically using zoomScale. 使用zoomScale动态调整contentInset。 I just implement only
Lanscape mode
for testing, but Portrait mode
is exactly the same way. 我只是实现了
Lanscape mode
进行测试,但是Portrait mode
完全相同。
// adjust contentInset
CGFloat increasingZoomScale = (scrollView.zoomScale == 1) ? 0 : (-1 * (1 - scrollView.zoomScale));
CGRect cropRect = [SKPhotoCropFrameView getCropRectFromOrientation:self.photoCropOrientation];
CGRect aspectFitRect = AVMakeRectWithAspectRatioInsideRect(self.selectedImageView.image.size, self.selectedImageView.frame);
CGFloat difference = fabsf(cropRect.size.height - aspectFitRect.size.height);
// implement at `Landscape` mode first
if (self.photoCropOrientation == SKPhotoCropOrientationPortrait) {
}else{
// get scaledFrameHeight because it's `Landscape` crop mode
CGFloat increasingFrameHeight = scrollView.frame.size.height * increasingZoomScale;
self.contentInset = UIEdgeInsetsMake(difference/2 - increasingFrameHeight/2, 0, difference/2 - increasingFrameHeight/2, 0);
}
And bam. 和bam。 here is the screenshot.
这是截图。
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