我想设置一个UILabel的左插图/边距,但找不到这样做的方法。标签有一个背景集,所以仅仅改变它的原点是行不通的。这将是理想的插入文本10px左右在左手边。
当前回答
在Swift 3中,你可以通过创建UILabel的子类来达到你想要的效果。在这个子类中,你必须添加一个UIEdgeInsets属性,并覆盖drawText(In:)方法,intrinsicContentSize属性(用于自动布局代码)和/或sizeThatFits(_:)方法(用于Springs和Struts代码)。
import UIKit
class PaddingLabel: UILabel {
let padding: UIEdgeInsets
// Create a new PaddingLabel instance programamtically with the desired insets
required init(padding: UIEdgeInsets = UIEdgeInsets(top: 0, left: 10, bottom: 0, right: 10)) {
self.padding = padding
super.init(frame: CGRect.zero)
}
// Create a new PaddingLabel instance programamtically with default insets
override init(frame: CGRect) {
padding = UIEdgeInsets.zero // set desired insets value according to your needs
super.init(frame: frame)
}
// Create a new PaddingLabel instance from Storyboard with default insets
required init?(coder aDecoder: NSCoder) {
padding = UIEdgeInsets.zero // set desired insets value according to your needs
super.init(coder: aDecoder)
}
override func drawText(in rect: CGRect) {
super.drawText(in: UIEdgeInsetsInsetRect(rect, padding))
}
// Override `intrinsicContentSize` property for Auto layout code
override var intrinsicContentSize: CGSize {
let superContentSize = super.intrinsicContentSize
let width = superContentSize.width + padding.left + padding.right
let height = superContentSize.height + padding.top + padding.bottom
return CGSize(width: width, height: height)
}
// Override `sizeThatFits(_:)` method for Springs & Struts code
override func sizeThatFits(_ size: CGSize) -> CGSize {
let superSizeThatFits = super.sizeThatFits(size)
let width = superSizeThatFits.width + padding.left + padding.right
let heigth = superSizeThatFits.height + padding.top + padding.bottom
return CGSize(width: width, height: heigth)
}
}
下面的例子展示了如何在UIViewController中使用PaddingLabel实例:
import UIKit
class ViewController: UIViewController {
@IBOutlet weak var storyboardAutoLayoutLabel: PaddingLabel!
let autoLayoutLabel = PaddingLabel(padding: UIEdgeInsets(top: 20, left: 40, bottom: 20, right: 40))
let springsAndStructsLabel = PaddingLabel(frame: CGRect.zero)
var textToDisplay = "Lorem ipsum dolor sit er elit lamet."
override func viewDidLoad() {
super.viewDidLoad()
// Set autoLayoutLabel
autoLayoutLabel.text = textToDisplay
autoLayoutLabel.backgroundColor = .red
autoLayoutLabel.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(autoLayoutLabel)
autoLayoutLabel.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 30).isActive = true
autoLayoutLabel.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
// Set springsAndStructsLabel
springsAndStructsLabel.text = textToDisplay
springsAndStructsLabel.backgroundColor = .green
view.addSubview(springsAndStructsLabel)
springsAndStructsLabel.frame.origin = CGPoint(x: 30, y: 90)
springsAndStructsLabel.sizeToFit()
// Set storyboardAutoLayoutLabel
storyboardAutoLayoutLabel.text = textToDisplay
storyboardAutoLayoutLabel.backgroundColor = .blue
}
// Link this IBAction to a UIButton or a UIBarButtonItem in Storyboard
@IBAction func updateLabelText(_ sender: Any) {
textToDisplay = textToDisplay == "Lorem ipsum dolor sit er elit lamet." ? "Lorem ipsum." : "Lorem ipsum dolor sit er elit lamet."
// autoLayoutLabel
autoLayoutLabel.text = textToDisplay
// springsAndStructsLabel
springsAndStructsLabel.text = textToDisplay
springsAndStructsLabel.sizeToFit()
// storyboardAutoLayoutLabel
storyboardAutoLayoutLabel.text = textToDisplay
}
}
其他回答
不要编码,Xcode !
比起使用UILabel来解决这个问题,我建议你去看看UIButton。它提供了开箱即用的功能,可以在大小检查器中设置内容插入(上、左、下、右)。设置所需的边距,然后在Xcode中禁用按钮,完成。
这是我发现的最简单的方法。这对我来说很有魔力。
UIView *titleSection = [[UIView alloc] initWithFrame:CGRectMake(0, 0, screenWidth, 100)];
[titleSection addSubview:titleSection];
UILabel *label = [[UILabel alloc] initWithFrame:CGRectInset(titleSection.frame, PADDING, 0)];
[titleSection addSubview:label];
对于Xamarin用户(使用统一API):
class UIMarginLabel : UILabel
{
public UIMarginLabel()
{
}
public UIMarginLabel( CGRect frame ) : base( frame )
{
}
public UIEdgeInsets Insets { get; set; }
public override void DrawText( CGRect rect )
{
base.DrawText( Insets.InsetRect( rect ) );
}
}
对于那些使用原始MonoTouch API的人:
public class UIMarginLabel : UILabel
{
public UIEdgeInsets Insets { get; set; }
public UIMarginLabel() : base()
{
Insets = new UIEdgeInsets(0, 0, 0, 0);
}
public UIMarginLabel(RectangleF frame) : base(frame)
{
Insets = new UIEdgeInsets(0, 0, 0, 0);
}
public override void DrawText(RectangleF frame)
{
base.DrawText(new RectangleF(
frame.X + Insets.Left,
frame.Y + Insets.Top,
frame.Width - Insets.Left - Insets.Right,
frame.Height - Insets.Top - Insets.Bottom));
}
}
Swift 3 &自动布局兼容版本:
class InsetLabel: UILabel {
var insets = UIEdgeInsets()
convenience init(insets: UIEdgeInsets) {
self.init(frame: CGRect.zero)
self.insets = insets
}
convenience init(dx: CGFloat, dy: CGFloat) {
let insets = UIEdgeInsets(top: dy, left: dx, bottom: dy, right: dx)
self.init(insets: insets)
}
override func drawText(in rect: CGRect) {
super.drawText(in: UIEdgeInsetsInsetRect(rect, insets))
}
override var intrinsicContentSize: CGSize {
var size = super.intrinsicContentSize
size.width += insets.left + insets.right
size.height += insets.top + insets.bottom
return size
}
}
这适用于多行标签:
class PaddedLabel: UILabel {
var verticalPadding: CGFloat = 0
var horizontalPadding: CGFloat = 0
override func drawText(in rect: CGRect) {
let insets = UIEdgeInsets(top: verticalPadding, left: horizontalPadding, bottom: verticalPadding, right: horizontalPadding)
super.drawText(in: UIEdgeInsetsInsetRect(rect, insets))
}
override var intrinsicContentSize: CGSize {
get {
let textWidth = super.intrinsicContentSize.width - horizontalPadding * 2
let textHeight = sizeThatFits(CGSize(width: textWidth, height: .greatestFiniteMagnitude)).height
let width = textWidth + horizontalPadding * 2
let height = textHeight + verticalPadding * 2
return CGSize(width: frame.width, height: height)
}
}
}
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