调整动画大小后,UIButton不尊重Aspect Fill contentMode

Question

我使用自动布局.以下是视图的初始状态.

中间是视图中包含的按钮.该按钮具有contentMode Aspect Fill,并且图像被设置为按钮的背景图像.

然后我使用以下代码转换视图,这将放大中心卡以填充屏幕,并将图像移动到视图的顶部:

cardTrailingSpaceConstraint.constant = 0
cardLeadingSpaceConstraint.constant = 0
cardView.removeConstraint(cardAspectRatioConstraint)
let cardHeightConstraint = NSLayoutConstraint(item: cardView, attribute: .Height, relatedBy: .Equal, toItem: view, attribute: .Height, multiplier: 1.0, constant: 0)
view.addConstraint(cardHeightConstraint)

dishImageButton.removeConstraint(dishButtonBottomSpaceConstraint)
let dishButtonHeightConstraint = NSLayoutConstraint(item: dishImageButton, attribute: .Height, relatedBy: .Equal, toItem: cardView, attribute: .Height, multiplier: 0.2, constant: 0)
cardView.addConstraint(dishButtonHeightConstraint)

cardView.setNeedsUpdateConstraints()
UIView.animateWithDuration(0.7, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 0.7, options: nil, animations: { [unowned self] () -> Void in
    self.cardHeader.alpha = 0
    self.cardView.layer.cornerRadius = 0
    self.cardView.layoutIfNeeded()

    }) { [unowned self] (finished) -> Void in

        }

结果是:

但是,这不是我想要的.该按钮不符合contentMode,然后图像被拉伸.

任何人都可以告诉我如何维护按钮的Aspect Fill contentMode？

Answer 1

1. 将按钮类型设置为UIButtonTypeCustom(故事板或xib中的"自定义").
2. 设置按钮的图像,而不是按钮的背景图像.
3. 在viewDidLoad,设置button.imageView.contentMode为UIViewContentMode.ScaleAspectFill.

Answer 2

斯威夫特3

离开Rob的回答:

    let btn = UIButton(frame: CGRect(x: 0, y: 0, width: 80, height: 30))
    btn.setImage(UIImage(named: "albumsBtn"), for: UIControlState.normal)
    btn.imageView?.contentMode = UIViewContentMode.scaleAspectFit
    btn.addTarget(self.navigationController, action: #selector(CustomGalleryViewController.showAlbums(_:)), for:  UIControlEvents.touchUpInside)
    let item = UIBarButtonItem(customView: btn)
    self.navigationItem.leftBarButtonItem = item

Answer 3

斯威夫特2

button.imageView?.contentMode = UIViewContentMode.ScaleAspectFit

所有contentMode:

  .ScaleToFill
   .ScaleAspectFit
   .ScaleAspectFill
   .Redraw 
   .Center 
   .Top
   .Bottom
   .Left
   .Right
   .TopLeft
   .TopRight
   .BottomLeft
   .BottomRight

Answer 4

在[btn setImage：forState：]用法之前尝试以下操作：

    btn.contentHorizontalAlignment = UIControlContentHorizontalAlignmentFill;
    btn.contentVerticalAlignment = UIControlContentVerticalAlignmentFill;

• 斯威夫特4

//Center
btn.contentHorizontalAlignment = UIControl.ContentHorizontalAlignment.center

//Left
btn.contentHorizontalAlignment = UIControl.ContentHorizontalAlignment.left

//Right
btn.contentHorizontalAlignment = UIControl.ContentHorizontalAlignment.right

Answer 5

在Xcode 10.1中，您可以使用界面生成器。在右侧的属性检查器中，使用“控制”部分，如下所示：

Answer 6

迅速

对于按钮有 contentMode Aspect Fill：

btn.contentHorizontalAlignment = .fill
btn.contentVerticalAlignment = .fill
btn.imageView?.contentMode = .scaleAspectFill

Answer 7

Swift 2.x版本:

let myButton = UIButton(type: .Custom)
myButton.frame = CGRectMake(0, 0, 200, 20)
myButton.backgroundColor = UIColor.blackColor()
myButton.imageView.contentMode = .ScaleAspectFill // ALTERNATIVE:  .ScaleAspectFit
myButton.setImage(UIImage(named: "myImageName"), forState: .Normal)
myButton.addTarget(self, action: #selector(buttonAction), forControlEvents: .TouchUpInside)
view.addSubview(myButton)

Answer 8

斯威夫特4.2

延期

// Inspectable image content mode
extension UIButton {
    /// 0 => .ScaleToFill
    /// 1 => .ScaleAspectFit
    /// 2 => .ScaleAspectFill
    @IBInspectable
    var imageContentMode: Int {
        get {
            return self.imageView?.contentMode.rawValue ?? 0
        }
        set {
            if let mode = UIViewContentMode(rawValue: newValue),
                self.imageView != nil {
                self.imageView?.contentMode = mode
            }
        }
    }
}

更新：此和其他答案不适用于ios11。最接近的答案是@Jaro，但我认为最好制作一个UIImageView并在其上添加一个按钮，或者创建一个自定义类的UIImageView手势识别器，然后单击动画。

Answer 9

语言似乎有了更新。

我不得不深入挖掘以获得 xcoder 解决方案：

myButton.imageView.contentMode = .ScaleAspectFill 

更新后的版本如下：

myButton.imageView?.contentMode = UIView.ContentMode.scaleAspectFit