在UIButton中加下划线-Java 学习之路

130

任何人都可以建议如何强调UIButton的 Headers ？我有一个自定义类型的UIButton，我希望 Headers 有下划线，但Interface Builder没有提供任何选项 .

在Interface Builder中为按钮选择字体选项时，它提供了选择无，单，双，颜色的选项，但这些选项都不会对按钮上的 Headers 进行任何更改 .

任何帮助赞赏 .

17 回答

UIUnderlinedButton.h

@interface UIUnderlinedButton : UIButton {

}


+ (UIUnderlinedButton*) underlinedButton;
@end

UIUnderlinedButton.m

@implementation UIUnderlinedButton

+ (UIUnderlinedButton*) underlinedButton {
    UIUnderlinedButton* button = [[UIUnderlinedButton alloc] init];
    return [button autorelease];
}

- (void) drawRect:(CGRect)rect {
    CGRect textRect = self.titleLabel.frame;

    // need to put the line at top of descenders (negative value)
    CGFloat descender = self.titleLabel.font.descender;

    CGContextRef contextRef = UIGraphicsGetCurrentContext();

    // set to same colour as text
    CGContextSetStrokeColorWithColor(contextRef, self.titleLabel.textColor.CGColor);

    CGContextMoveToPoint(contextRef, textRect.origin.x, textRect.origin.y + textRect.size.height + descender);

    CGContextAddLineToPoint(contextRef, textRect.origin.x + textRect.size.width, textRect.origin.y + textRect.size.height + descender);

    CGContextClosePath(contextRef);

    CGContextDrawPath(contextRef, kCGPathStroke);
}


@end

回复于 2024-05-04T02:45:50+08:00

78
要使用界面构建器加下划线，必须：
- 将其更改为属性
- 突出显示“属性”检查器中的文本
- 右键单击，选择“字体”，然后选择“下划线”
Video someone else made https://www.youtube.com/watch?v=5-ZnV3jQd9I
回复于 2024-05-04T02:45:50+08:00

351

从iOS6开始，现在可以使用NSAttributedString以更灵活的方式执行下划线（以及其他任何归因于字符串支持的内容）：

NSMutableAttributedString *commentString = [[NSMutableAttributedString alloc] initWithString:@"The Quick Brown Fox"];

[commentString addAttribute:NSUnderlineStyleAttributeName value:[NSNumber numberWithInteger:NSUnderlineStyleSingle] range:NSMakeRange(0, [commentString length])];

[button setAttributedTitle:commentString forState:UIControlStateNormal];

注意：将此添加为另一个答案 - 因为它与我之前的解决方案完全不同 .

Edit: 奇怪（至少在iOS8中）你必须为第一个字符加下划线，否则它不起作用！

所以作为一种解决方法，将第一个char设置为带有明确颜色的下划线！

// underline Terms and condidtions
    NSMutableAttributedString* tncString = [[NSMutableAttributedString alloc] initWithString:@"View Terms and Conditions"];

    // workaround for bug in UIButton - first char needs to be underlined for some reason!
    [tncString addAttribute:NSUnderlineStyleAttributeName
                      value:@(NSUnderlineStyleSingle)
                      range:(NSRange){0,1}];
    [tncString addAttribute:NSUnderlineColorAttributeName value:[UIColor clearColor] range:NSMakeRange(0, 1)];


    [tncString addAttribute:NSUnderlineStyleAttributeName
                      value:@(NSUnderlineStyleSingle)
                      range:(NSRange){5,[tncString length] - 5}];

    [tncBtn setAttributedTitle:tncString forState:UIControlStateNormal];

回复于 2024-05-04T02:45:50+08:00

4
您可以在界面构建器本身中执行此操作 .
- 选择属性检查器
- 将 Headers 类型从普通更改为属性
- 设置适当的字体大小和文本对齐方式
- 然后选择 Headers 文本并将字体设置为带下划线
回复于 2024-05-04T02:45:50+08:00

使用属性字符串非常简单

创建具有set属性的字典并应用于属性字符串 . 然后，您可以将uibutton中的属性字符串设置为attibutedtitle或uilabel中的attributestext .

NSDictionary *attrDict = @{NSFontAttributeName : [UIFont
 systemFontOfSize:14.0],NSForegroundColorAttributeName : [UIColor
 whiteColor]};
 NSMutableAttributedString *title =[[NSMutableAttributedString alloc] initWithString:@"mybutton" attributes: attrDict]; 
[title addAttribute:NSUnderlineStyleAttributeName value:[NSNumber numberWithInteger:NSUnderlineStyleSingle] range:NSMakeRange(0,[commentString length])]; [btnRegLater setAttributedTitle:title forState:UIControlStateNormal];

回复于 2024-05-04T02:45:50+08:00

这是我的功能，适用于Swift 1.2 .

func underlineButton(button : UIButton, text: String) {

    var titleString : NSMutableAttributedString = NSMutableAttributedString(string: text)
    titleString.addAttribute(NSUnderlineStyleAttributeName, value: NSUnderlineStyle.StyleSingle.rawValue, range: NSMakeRange(0, count(text.utf8)))
    button.setAttributedTitle(titleString, forState: .Normal)
}

更新Swift 3.0扩展：

extension UIButton {
    func underlineButton(text: String) {
        let titleString = NSMutableAttributedString(string: text)
        titleString.addAttribute(NSUnderlineStyleAttributeName, value: NSUnderlineStyle.styleSingle.rawValue, range: NSMakeRange(0, text.characters.count))
        self.setAttributedTitle(titleString, for: .normal)
    }
}

回复于 2024-05-04T02:45:50+08:00

33
尼克的答案是一个很好的，快速的方法来做到这一点 .

我在 drawRect 中添加了对阴影的支持 .

如果您的按钮 Headers 在文本下方有阴影，则Nick的回答不会考虑：

但你可以将下划线向下移动阴影的高度，如下所示：
```
CGFloat descender = self.titleLabel.font.descender;
CGContextRef contextRef = UIGraphicsGetCurrentContext();
CGFloat shadowHeight = self.titleLabel.shadowOffset.height;
descender += shadowHeight;
```
然后你会得到这样的东西：
回复于 2024-05-04T02:45:50+08:00

125

对于Swift 3，可以使用以下扩展名：

extension UIButton {
    func underlineButton(text: String) {
        let titleString = NSMutableAttributedString(string: text)
        titleString.addAttribute(NSUnderlineStyleAttributeName, value: NSUnderlineStyle.styleSingle.rawValue, range: NSMakeRange(0, text.characters.count))
        self.setAttributedTitle(titleString, for: .normal)
    }
}

回复于 2024-05-04T02:45:50+08:00

// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
CGRect textRect = self.titleLabel.frame;

// need to put the line at top of descenders (negative value)
CGFloat descender = self.titleLabel.font.descender;

CGContextRef contextRef = UIGraphicsGetCurrentContext();
UIColor *colr;
// set to same colour as text
if (self.isHighlighted || self.isSelected) {
    colr=self.titleLabel.highlightedTextColor;
}
else{
    colr= self.titleLabel.textColor;
}
CGContextSetStrokeColorWithColor(contextRef, colr.CGColor);

CGContextMoveToPoint(contextRef, textRect.origin.x, textRect.origin.y +        textRect.size.height + descender);

CGContextAddLineToPoint(contextRef, textRect.origin.x + textRect.size.width, textRect.origin.y + textRect.size.height + descender);

CGContextClosePath(contextRef);

CGContextDrawPath(contextRef, kCGPathStroke);
}
//Override this to change the underline color to highlighted color
-(void)setHighlighted:(BOOL)highlighted
{
[super setHighlighted:highlighted];
// [self setNeedsDisplay];
}

回复于 2024-05-04T02:45:50+08:00

扩展了@Nick H247的答案，我遇到了一个问题，首先当按钮在旋转时调整大小时，下划线没有重绘;这可以通过将按钮设置为重绘来解决：

myButton.contentMode = UIViewContentModeRedraw;

这会强制按钮在边界更改时重绘 .

其次，原始代码假设您在按钮中只有1行文本（我的按钮在旋转时包含2行），并且下划线仅出现在文本的最后一行 . 可以修改drawRect代码以首先计算按钮中的行数，然后在每一行而不是底部添加下划线，如下所示：

- (void) drawRect:(CGRect)rect {
CGRect textRect = self.titleLabel.frame;

// need to put the line at top of descenders (negative value)
CGFloat descender = self.titleLabel.font.descender;

CGContextRef contextRef = UIGraphicsGetCurrentContext();

// set to same colour as text
CGContextSetStrokeColorWithColor(contextRef, self.titleLabel.textColor.CGColor);

CGSize labelSize = [self.titleLabel.text sizeWithFont:self.titleLabel.font
                            constrainedToSize:self.titleLabel.frame.size
                                lineBreakMode:UILineBreakModeWordWrap];

CGSize labelSizeNoWrap = [self.titleLabel.text sizeWithFont:self.titleLabel.font forWidth:self.titleLabel.frame.size.width lineBreakMode:UILineBreakModeMiddleTruncation ];

int numberOfLines = abs(labelSize.height/labelSizeNoWrap.height);

for(int i = 1; i<=numberOfLines;i++) {
 //        Original code
 //        CGContextMoveToPoint(contextRef, textRect.origin.x, textRect.origin.y + textRect.size.height + descender + PADDING);
 //        
 //        CGContextAddLineToPoint(contextRef, textRect.origin.x + textRect.size.width, textRect.origin.y + textRect.size.height + descender);

    CGContextMoveToPoint(contextRef, textRect.origin.x, textRect.origin.y + (labelSizeNoWrap.height*i) + descender + PADDING);

    CGContextAddLineToPoint(contextRef, textRect.origin.x + textRect.size.width, textRect.origin.y + (labelSizeNoWrap.height*i) + descender);

    CGContextClosePath(contextRef);

    CGContextDrawPath(contextRef, kCGPathStroke);

}


}

希望这段代码可以帮助别人！

回复于 2024-05-04T02:45:50+08:00

在迅速

func underlineButton(button : UIButton) {

var titleString : NSMutableAttributedString = NSMutableAttributedString(string: button.titleLabel!.text!)
titleString.addAttribute(NSUnderlineStyleAttributeName, value: NSUnderlineStyle.StyleSingle.rawValue, range: NSMakeRange(0, button.titleLabel!.text!.utf16Count))
button.setAttributedTitle(titleString, forState: .Normal)}

回复于 2024-05-04T02:45:50+08:00

1

当按下加下划线的按钮时，如何处理案例？在这种情况下，按钮的文本颜色会根据突出显示的颜色而改变，但线条保留原始颜色 . 假设正常状态下的按钮文字颜色是黑色，那么它的下划线也会有黑色 . 按钮的突出显示颜色为白色 . 按住按钮可将按钮文本颜色从黑色更改为白色，但下划线颜色保持黑色 .

回复于 2024-05-04T02:45:50+08:00
3

我相信这是XCode中字体编辑器中的一些错误 . 如果使用界面构建器，则必须将 Headers 从Plain更改为Attributed，打开TextEdit创建带下划线的文本并将其复制粘贴到XCode中的文本框

回复于 2024-05-04T02:45:50+08:00

尼克H247的答案，但斯威夫特方法：

import UIKit

class UnderlineUIButton: UIButton {

    override func drawRect(rect: CGRect) {
        super.drawRect(rect)

        let textRect = self.titleLabel!.frame

        var descender = self.titleLabel?.font.descender

        var contextRef: CGContextRef = UIGraphicsGetCurrentContext();

        CGContextSetStrokeColorWithColor(contextRef, self.titleLabel?.textColor.CGColor);

        CGContextMoveToPoint(contextRef, textRect.origin.x, textRect.origin.y + textRect.size.height + descender!);

        CGContextAddLineToPoint(contextRef, textRect.origin.x + textRect.size.width, textRect.origin.y + textRect.size.height + descender!);

        CGContextClosePath(contextRef);

        CGContextDrawPath(contextRef, kCGPathStroke);
    }
}

回复于 2024-05-04T02:45:50+08:00

You can use this code to add underline with spacing in button.

当我尝试从界面构建器中绘制下划线时 . 它看起来像下面的图像 .

1 - Interface builder reference

使用下面的代码后，我按照自己的意愿实现了结果 .

2 - using described code

public func setTextUnderline()
    {
        let dummyButton: UIButton = UIButton.init()
        dummyButton.setTitle(self.titleLabel?.text, for: .normal)
        dummyButton.titleLabel?.font = self.titleLabel?.font
        dummyButton.sizeToFit()

        let dummyHeight = dummyButton.frame.size.height + 3

        let bottomLine = CALayer()
        bottomLine.frame = CGRect.init(x: (self.frame.size.width - dummyButton.frame.size.width)/2, y: -(self.frame.size.height - dummyHeight), width: dummyButton.frame.size.width, height: 1.0)
        bottomLine.backgroundColor = self.titleLabel?.textColor.cgColor
        self.layer.addSublayer(bottomLine)
    }

回复于 2024-05-04T02:45:50+08:00

用于@NickH247's的Swift 3版本，自定义下划线颜色，线宽和间隙：

import Foundation

class UnderlinedButton: UIButton {

    private let underlineColor: UIColor
    private let thickness: CGFloat
    private let gap: CGFloat

    init(underlineColor: UIColor, thickness: CGFloat, gap: CGFloat, frame: CGRect? = nil) {
        self.underlineColor = underlineColor
        self.thickness = thickness
        self.gap = gap
        super.init(frame: frame ?? .zero)
    }

    override func draw(_ rect: CGRect) {
        super.draw(rect)

        guard let textRect = titleLabel?.frame,
            let decender = titleLabel?.font.descender,
            let context = UIGraphicsGetCurrentContext() else { return }

        context.setStrokeColor(underlineColor.cgColor)
        context.move(to: CGPoint(x: textRect.origin.x, y: textRect.origin.y + textRect.height + decender + gap))
        context.setLineWidth(thickness)
        context.addLine(to: CGPoint(x: textRect.origin.x + textRect.width, y: textRect.origin.y + textRect.height + decender + gap))
        context.closePath()
        context.drawPath(using: .stroke)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

回复于 2024-05-04T02:45:50+08:00

func underline(text: String, state: UIControlState = .normal, color:UIColor? = nil) {
        var titleString = NSMutableAttributedString(string: text)

        if let color = color {
            titleString = NSMutableAttributedString(string: text,
                               attributes: [NSForegroundColorAttributeName: color])
        }

        let stringRange = NSMakeRange(0, text.characters.count)
        titleString.addAttribute(NSUnderlineStyleAttributeName,
                                 value: NSUnderlineStyle.styleSingle.rawValue,
                                 range: stringRange)

        self.setAttributedTitle(titleString, for: state)
    }

回复于 2024-05-04T02:45:50+08:00

在UIButton中加下划线

17 回答

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