我想在两行文本的左边放置一个图标，这样在图像和文本开始之间有大约2-3像素的空间。控件本身水平居中对齐(通过接口生成器设置)
这个按钮应该是这样的:
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|[Image] Add To |
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我试图配置这与contenttedgeinset, imageEdgeInsets和titleEdgeInsets无效。我知道，负值会使边缘扩大，而正值会使边缘缩小，使边缘更接近中心。
我试着:
[button setTitleEdgeInsets:UIEdgeInsetsMake(0, -image.size.width, 0, 0)];
[button setImageEdgeInsets:UIEdgeInsetsMake(0, button.titleLabel.bounds.size.width, 0, 0)];
但这并没有正确显示它。我一直在调整这些值，但从-5到-10的左插入值似乎不会以预期的方式移动它。-10将文本一直向左移动，所以我期望-5将它从左侧移动一半，但事实并非如此。
嵌套背后的逻辑是什么?我不熟悉图像放置和相关术语。
我用这个SO问题作为参考，但我的价值观有些不对。
UIButton:如何使用imageEdgeInsets和titleEdgeInsets居中图像和文本?
我的垂直定心方法:
extension UIButton {
/// Layout image and title with vertical centering.
/// - Parameters:
/// - size: The button size.
/// - imageTopOffset: Top offset for image.
/// - spacing: Distance between image and title.
func verticalAlignmentByCenter(size: CGSize, imageTopOffset: CGFloat, spacing: CGFloat) {
let contentRect = contentRect(forBounds: CGRect(origin: .zero, size: size))
let imageRect = imageRect(forContentRect: contentRect)
let titleRect = titleRect(forContentRect: contentRect)
let imageTop = imageTopOffset - imageRect.origin.y
let imageLeft = contentRect.width/2 - imageRect.width/2
imageEdgeInsets = UIEdgeInsets(top: imageTop, left: imageLeft, bottom: 0, right: 0)
let titleTop = imageTopOffset + spacing + imageRect.height - titleRect.origin.y
let titleLeft = titleRect.origin.x - contentRect.width/2 - titleRect.width/2
titleEdgeInsets = UIEdgeInsets(top: titleTop, left: titleLeft, bottom: 0, right: 0)
}
}
@ravron非常出色地给出了这个答案。
在我的例子中，我不仅需要在图像和标题之间添加水平宽度，还需要在按钮的“开头”和“结尾”添加水平空间。
因此，我使用了内部图像和标签的intrinsicContentSize:
接收视图的自然大小，只考虑视图本身的属性。
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|[LEADING SPACE] [Image] [SPACE BETWEEN IMAGE AND TITLE] Add To [TRAILING SPACE]|
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let leadingTrailingSpace = 10
let horizontalWidthBetweenImageAndTitle = 4
let insetAmount = horizontalWidthBetweenImageAndTitle / CGFloat(2)
button.imageEdgeInsets = UIEdgeInsets(top: 0, left: -CGFloat(insetAmount), bottom: 0, right: insetAmount);
button.titleEdgeInsets = UIEdgeInsets(top: 0, left: CGFloat(insetAmount), bottom: 0, right: -insetAmount);
button.contentEdgeInsets = UIEdgeInsets(top: 0, left: CGFloat(insetAmount), bottom: 0, right: insetAmount);
let buttonWidth =
(button.titleLabel?.intrinsicContentSize.width ?? 0) +
(button.imageView?.intrinsicContentSize.width ?? 0)
+ insetAmount
+ leadingTrailingSpace
button.widthAnchor.constraint(equalToConstant: buttonWidth).isActive = true
下面是我写的代码。它在产品版本中运行良好。支持Swift 4.2 +
extension UIButton{
enum ImageTitleRelativeLocation {
case imageUpTitleDown
case imageDownTitleUp
case imageLeftTitleRight
case imageRightTitleLeft
}
func centerContentRelativeLocation(_ relativeLocation:
ImageTitleRelativeLocation,
spacing: CGFloat = 0) {
assert(contentVerticalAlignment == .center,
"only works with contentVerticalAlignment = .center !!!")
guard (title(for: .normal) != nil) || (attributedTitle(for: .normal) != nil) else {
assert(false, "TITLE IS NIL! SET TITTLE FIRST!")
return
}
guard let imageSize = self.currentImage?.size else {
assert(false, "IMGAGE IS NIL! SET IMAGE FIRST!!!")
return
}
guard let titleSize = titleLabel?
.systemLayoutSizeFitting(UIView.layoutFittingCompressedSize) else {
assert(false, "TITLELABEL IS NIL!")
return
}
let horizontalResistent: CGFloat
// extend contenArea in case of title is shrink
if frame.width < titleSize.width + imageSize.width {
horizontalResistent = titleSize.width + imageSize.width - frame.width
print("horizontalResistent", horizontalResistent)
} else {
horizontalResistent = 0
}
var adjustImageEdgeInsets: UIEdgeInsets = .zero
var adjustTitleEdgeInsets: UIEdgeInsets = .zero
var adjustContentEdgeInsets: UIEdgeInsets = .zero
let verticalImageAbsOffset = abs((titleSize.height + spacing) / 2)
let verticalTitleAbsOffset = abs((imageSize.height + spacing) / 2)
switch relativeLocation {
case .imageUpTitleDown:
adjustImageEdgeInsets.top = -verticalImageAbsOffset
adjustImageEdgeInsets.bottom = verticalImageAbsOffset
adjustImageEdgeInsets.left = titleSize.width / 2 + horizontalResistent / 2
adjustImageEdgeInsets.right = -titleSize.width / 2 - horizontalResistent / 2
adjustTitleEdgeInsets.top = verticalTitleAbsOffset
adjustTitleEdgeInsets.bottom = -verticalTitleAbsOffset
adjustTitleEdgeInsets.left = -imageSize.width / 2 + horizontalResistent / 2
adjustTitleEdgeInsets.right = imageSize.width / 2 - horizontalResistent / 2
adjustContentEdgeInsets.top = spacing
adjustContentEdgeInsets.bottom = spacing
adjustContentEdgeInsets.left = -horizontalResistent
adjustContentEdgeInsets.right = -horizontalResistent
case .imageDownTitleUp:
adjustImageEdgeInsets.top = verticalImageAbsOffset
adjustImageEdgeInsets.bottom = -verticalImageAbsOffset
adjustImageEdgeInsets.left = titleSize.width / 2 + horizontalResistent / 2
adjustImageEdgeInsets.right = -titleSize.width / 2 - horizontalResistent / 2
adjustTitleEdgeInsets.top = -verticalTitleAbsOffset
adjustTitleEdgeInsets.bottom = verticalTitleAbsOffset
adjustTitleEdgeInsets.left = -imageSize.width / 2 + horizontalResistent / 2
adjustTitleEdgeInsets.right = imageSize.width / 2 - horizontalResistent / 2
adjustContentEdgeInsets.top = spacing
adjustContentEdgeInsets.bottom = spacing
adjustContentEdgeInsets.left = -horizontalResistent
adjustContentEdgeInsets.right = -horizontalResistent
case .imageLeftTitleRight:
adjustImageEdgeInsets.left = -spacing / 2
adjustImageEdgeInsets.right = spacing / 2
adjustTitleEdgeInsets.left = spacing / 2
adjustTitleEdgeInsets.right = -spacing / 2
adjustContentEdgeInsets.left = spacing
adjustContentEdgeInsets.right = spacing
case .imageRightTitleLeft:
adjustImageEdgeInsets.left = titleSize.width + spacing / 2
adjustImageEdgeInsets.right = -titleSize.width - spacing / 2
adjustTitleEdgeInsets.left = -imageSize.width - spacing / 2
adjustTitleEdgeInsets.right = imageSize.width + spacing / 2
adjustContentEdgeInsets.left = spacing
adjustContentEdgeInsets.right = spacing
}
imageEdgeInsets = adjustImageEdgeInsets
titleEdgeInsets = adjustTitleEdgeInsets
contentEdgeInsets = adjustContentEdgeInsets
setNeedsLayout()
}
}
