对于这个问题，这绝对是一个矫kill过正的问题，但是...在我的一个项目中，我首先必须实现一个按钮，该按钮的图标最左对齐。然后我们在图像下得到了另一个带有标题的按钮。我搜索了一个现有的解决方案，但是没有运气，因此，这里是可对齐的按钮：
@IBDesignable
class AlignableButton: UIButton {
override class var requiresConstraintBasedLayout: Bool {
return true
}
@objc enum IconAlignment: Int {
case top, left, right, bottom
}
// MARK: - Designables
@IBInspectable var iconAlignmentValue: Int {
set {
iconAlignment = IconAlignment(rawValue: newValue) ?? .left
}
get {
return iconAlignment.rawValue
}
}
var iconAlignment: IconAlignment = .left
@IBInspectable var titleAlignmentValue: Int {
set {
titleAlignment = NSTextAlignment(rawValue: newValue) ?? .left
}
get {
return titleAlignment.rawValue
}
}
var titleAlignment: NSTextAlignment = .left
// MARK: - Corner Radius
@IBInspectable
var cornerRadius: CGFloat {
get {
return layer.cornerRadius
}
set {
layer.masksToBounds = (newValue != 0)
layer.cornerRadius = newValue
}
}
// MARK: - Content size
override var intrinsicContentSize: CGSize {
switch iconAlignment {
case .top, .bottom:
return verticalAlignedIntrinsicContentSize
default:
return super.intrinsicContentSize
}
}
private var verticalAlignedIntrinsicContentSize: CGSize {
if let imageSize = imageView?.intrinsicContentSize,
let labelSize = titleLabel?.intrinsicContentSize {
let width = max(imageSize.width, labelSize.width) + contentEdgeInsets.left + contentEdgeInsets.right
let height = imageSize.height + labelSize.height + contentEdgeInsets.top + contentEdgeInsets.bottom
return CGSize(
width: ceil(width),
height: ceil(height)
)
}
return super.intrinsicContentSize
}
// MARK: - Image Rect
override func imageRect(forContentRect contentRect: CGRect) -> CGRect {
switch iconAlignment {
case .top:
return topAlignedImageRect(forContentRect: contentRect)
case .bottom:
return bottomAlignedImageRect(forContentRect: contentRect)
case .left:
return leftAlignedImageRect(forContentRect: contentRect)
case .right:
return rightAlignedImageRect(forContentRect: contentRect)
}
}
func topAlignedImageRect(forContentRect contentRect: CGRect) -> CGRect {
let rect = super.imageRect(forContentRect: contentRect)
let x = (contentRect.width - rect.width) / 2.0 + contentRect.minX
let y = contentRect.minY
let w = rect.width
let h = rect.height
return CGRect(
x: x,
y: y,
width: w,
height: h
).inset(by: imageEdgeInsets)
}
func bottomAlignedImageRect(forContentRect contentRect: CGRect) -> CGRect {
let rect = super.imageRect(forContentRect: contentRect)
let x = (contentRect.width - rect.width) / 2.0 + contentRect.minX
let y = contentRect.height - rect.height + contentRect.minY
let w = rect.width
let h = rect.height
return CGRect(
x: x,
y: y,
width: w,
height: h
).inset(by: imageEdgeInsets)
}
func leftAlignedImageRect(forContentRect contentRect: CGRect) -> CGRect {
let rect = super.imageRect(forContentRect: contentRect)
let x = contentRect.minX
let y = (contentRect.height - rect.height) / 2 + contentRect.minY
let w = rect.width
let h = rect.height
return CGRect(
x: x,
y: y,
width: w,
height: h
).inset(by: imageEdgeInsets)
}
func rightAlignedImageRect(forContentRect contentRect: CGRect) -> CGRect {
let rect = super.imageRect(forContentRect: contentRect)
let x = (contentRect.width - rect.width) + contentRect.minX
let y = (contentRect.height - rect.height) / 2 + contentRect.minY
let w = rect.width
let h = rect.height
return CGRect(
x: x,
y: y,
width: w,
height: h
).inset(by: imageEdgeInsets)
}
// MARK: - Title Rect
override func titleRect(forContentRect contentRect: CGRect) -> CGRect {
switch iconAlignment {
case .top:
return topAlignedTitleRect(forContentRect: contentRect)
case .bottom:
return bottomAlignedTitleRect(forContentRect: contentRect)
case .left:
return leftAlignedTitleRect(forContentRect: contentRect)
case .right:
return rightAlignedTitleRect(forContentRect: contentRect)
}
}
func topAlignedTitleRect(forContentRect contentRect: CGRect) -> CGRect {
let rect = super.titleRect(forContentRect: contentRect)
let x = contentRect.minX
let y = contentRect.height - rect.height + contentRect.minY
let w = contentRect.width
let h = rect.height
return CGRect(
x: x,
y: y,
width: w,
height: h
).inset(by: titleEdgeInsets)
}
func bottomAlignedTitleRect(forContentRect contentRect: CGRect) -> CGRect {
let rect = super.titleRect(forContentRect: contentRect)
let x = contentRect.minX
let y = contentRect.minY
let w = contentRect.width
let h = rect.height
return CGRect(
x: x,
y: y,
width: w,
height: h
).inset(by: titleEdgeInsets)
}
func leftAlignedTitleRect(forContentRect contentRect: CGRect) -> CGRect {
let titleRect = super.titleRect(forContentRect: contentRect)
let imageRect = self.imageRect(forContentRect: contentRect)
let x = imageRect.width + imageRect.minX
let y = (contentRect.height - titleRect.height) / 2.0 + contentRect.minY
let w = contentRect.width - imageRect.width * 2.0
let h = titleRect.height
return CGRect(
x: x,
y: y,
width: w,
height: h
).inset(by: titleEdgeInsets)
}
func rightAlignedTitleRect(forContentRect contentRect: CGRect) -> CGRect {
let titleRect = super.titleRect(forContentRect: contentRect)
let imageRect = self.imageRect(forContentRect: contentRect)
let x = contentRect.minX + imageRect.width
let y = (contentRect.height - titleRect.height) / 2.0 + contentRect.minY
let w = contentRect.width - imageRect.width * 2.0
let h = titleRect.height
return CGRect(
x: x,
y: y,
width: w,
height: h
).inset(by: titleEdgeInsets)
}
// MARK: - Lifecycle
override func awakeFromNib() {
super.awakeFromNib()
titleLabel?.textAlignment = titleAlignment
}
override func prepareForInterfaceBuilder() {
super.prepareForInterfaceBuilder()
titleLabel?.textAlignment = titleAlignment
}
}
希望你觉得它有用。