Question

我试图以编程方式计算 UIImagePickerController 视图中顶部和底部工具栏的高度。

基本上，我指的是顶部包含相机控件的黑色区域和底部的圆形快门按钮。有没有办法做到这一点？

Sample image below

Answer 1

你可以用图片比例来做。最佳照片质量为3：4，因此如果在此设置下，Apple会调整视图以便在保持纵横比的同时显示整张照片。我非常确定你可以用它来计算这样的高度：

CGFloat screenWidth = [UIScreen mainScreen].bounds.size.width;
// at current screenwidth, 'previewHeight' is the height necessary to maintain the aspect ratio
CGFloat previewHeight = screenWidth + (screenWidth / 3);
CGFloat screenHeight = [UIScreen mainScreen].bounds.size.height;
CGFloat totalBlack = screenHeight - previewHeight;
CGFloat heightOfBlackTopAndBottom = totalBlack / 2;
NSLog(@"Height is: %f", heightOfBlackTopAndBottom);

它可能会更加优化，但我认为这可以更清楚地展示正在发生的事情。还要注意景观模式的潜在差异。

Answer 2

我一直面临同样的问题，因为我必须在UIImagePickerController之上添加叠加层。我通过迭代UIImagePickerController视图的子视图解决了这个问题，直到我得到了我需要的视图。这是一个例子：

- (void)updateOverlayPosition:(UIView *)superView {
    for (UIView *subview in superView.subviews) {
        //CMKTopBar is the class of top view
        if ([subview isKindOfClass:NSClassFromString(@"CMKTopBar")]) {
            self.defaultRect = CGRectMake(0,
                                          subview.frame.size.height,
                                          sizeOfYourOverlay,
                                          sizeOfYourOverlay);

            self.overLayView.frame = self.defaultRect;
        } else if ([subview isKindOfClass:NSClassFromString(@"PLCropOverlayBottomBar")]) {
            //after picture is taken, bottom bar vill appear with picture preview
            static const CGFloat diff = 2;

            self.alterRect = CGRectMake(0,
                                        [UIScreen mainScreen].bounds.size.height - sizeOfYourOverlay - subview.frame.size.height + diff,
                                        sizeOfYourOverlay,
                                        sizeOfYourOverlay);
        } else {
            [self updateOverlayPosition:subview];
        }
    }
}

您还可以使用“视图层次结构”工具获取所有视图的类名 http://cloud.obodev.com/3h2m3x351G0Q

重要时刻！在迭代UIImagePickerController视图的子视图之前，请确保它已经显示

- (void)showPicker {
    __weak typeof(self) weakSelf = self;

    [self presentViewController:self.pickerController
                       animated:YES
                     completion:^{
        __strong typeof(weakSelf) strongSelf = weakSelf;
        [strongSelf updateOverlayPosition:strongSelf.pickerController.view];
    }];
}

Answer 3

如果你想分别得到每个（顶部和底部）栏的高度（不是高度的总和）：

Swift 3代码：

class YourImagePickerController: UIImagePickerController {
    override func viewDidLayoutSubviews() {
        if let bottomBarView = self.view.findFirstSubview("CAMBottomBar"){
            print("bottom bar height: \(bottomBarView.frame.height)")
        }
    }
}

extension UIView {
    func findFirstSubview(_ className:String) -> UIView? {
        super.viewDidLayoutSubviews()
        for subview in self.subviewsRecursive() {
            if subview.className() == className {
                return subview
            }
        }
        return nil
    }

    func subviewsRecursive() -> [UIView] {
        return subviews + subviews.flatMap { $0.subviewsRecursive() }
    }
}

extension NSObject {
    func className() -> String {
        return String(describing: type(of: self))
    }
}

顶部栏类的名称是CAMTopBar

如何以编程方式计算UIImagePickerController工具栏的高度？

3 个答案: