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

没有子类和所有的爵士。我动态地做了这个:

[cell.textLabel setTranslatesAutoresizingMaskIntoConstraints:NO];
[cell.textLabel constraintTrailingEqualTo:cell.contentView constant:-100];

约束部分只是一个简单的代码糖纸(我们有相同的方法从上/下/左/右添加填充)..如果我在这里得到足够的爱,我将开放整个包装:

- (id)constraintTrailingEqualTo:(UIView *)toView constant:(CGFloat)constant
{
    NSLayoutConstraint *cn = [NSLayoutConstraint constraintWithItem:self
                                                          attribute:NSLayoutAttributeTrailing
                                                          relatedBy:NSLayoutRelationEqual
                                                             toItem:toView
                                                          attribute:NSLayoutAttributeTrailing
                                                         multiplier:1 constant:constant];

    [toView addConstraint:cn];
    return self;
}

(注意,我是在

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath: (NSIndexPath *)indexPath;

你可能需要调用[self setNeedsLayout];这取决于你的语境。

其他回答

对于多行文本,可以使用NSAttributedString设置左右边距。

NSMutableParagraphStyle *style =  [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
style.alignment = NSTextAlignmentJustified;
style.firstLineHeadIndent = 10.0f;
style.headIndent = 10.0f;
style.tailIndent = -10.0f;   

NSAttributedString *attrText = [[NSAttributedString alloc] initWithString:title attributes:@{ NSParagraphStyleAttributeName : style}];  

UILabel * label = [[UILabel alloc] initWithFrame:someFrame];
label.numberOfLines = 0;
label.attributedText = attrText;

以下是Swift 5采用的上述示例:

extension UILabel {
    func setMargins(margin: CGFloat = 10) {
        if let textString = self.text {
            var paragraphStyle = NSMutableParagraphStyle()
            paragraphStyle.firstLineHeadIndent = margin
            paragraphStyle.headIndent = margin
            paragraphStyle.tailIndent = -margin
            let attributedString = NSMutableAttributedString(string: textString)
            attributedString.addAttribute(.paragraphStyle, value: paragraphStyle, range: NSRange(location: 0, length: attributedString.length))
            attributedText = attributedString
        }
    }
}

很多答案都缺少对sizeThatFits的重写。有了这个子类,你可以创建标签,设置填充,然后输入label。sizetofit(),瞧。

import UIKit

class UILabelEx : UILabel
{
    var padding : UIEdgeInsets = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)

    override func drawTextInRect(rect: CGRect) {

        super.drawTextInRect(UIEdgeInsetsInsetRect(rect, padding))
    }

    override func sizeThatFits(size: CGSize) -> CGSize
    {

        var adjSize = super.sizeThatFits(size)
        adjSize.width += padding.left + padding.right
        adjSize.height += padding.top + padding.bottom

        return adjSize
    }
}

没有子类和所有的爵士。我动态地做了这个:

[cell.textLabel setTranslatesAutoresizingMaskIntoConstraints:NO];
[cell.textLabel constraintTrailingEqualTo:cell.contentView constant:-100];

约束部分只是一个简单的代码糖纸(我们有相同的方法从上/下/左/右添加填充)..如果我在这里得到足够的爱,我将开放整个包装:

- (id)constraintTrailingEqualTo:(UIView *)toView constant:(CGFloat)constant
{
    NSLayoutConstraint *cn = [NSLayoutConstraint constraintWithItem:self
                                                          attribute:NSLayoutAttributeTrailing
                                                          relatedBy:NSLayoutRelationEqual
                                                             toItem:toView
                                                          attribute:NSLayoutAttributeTrailing
                                                         multiplier:1 constant:constant];

    [toView addConstraint:cn];
    return self;
}

(注意,我是在

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath: (NSIndexPath *)indexPath;

你可能需要调用[self setNeedsLayout];这取决于你的语境。

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
    }
}