有谁能建议如何强调UIButton的标题?我有一个自定义类型的UIButton,我希望标题有下划线,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“标题”进行任何更改。
任何帮助表示感谢。
答案 0 :(得分:358)
要使用界面构建器加下划线,必须:
答案 1 :(得分:125)
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。
修改强> 奇怪的是(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!
以便解决方法,将第一个字符串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];
答案 2 :(得分:78)
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
答案 3 :(得分:39)
答案 4 :(得分:27)
归因于字符串
非常简单创建具有set属性的字典并应用于属性字符串。然后你可以将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];
答案 5 :(得分:19)
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扩展程序:
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)
}
}
答案 6 :(得分:13)
尼克的回答是一个很好的,快速的方法。
我在drawRect
中添加了对阴影的支持。
如果您的按钮标题在文字下方有阴影,则Nick的回答不会考虑:
但是您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:
答案 7 :(得分:5)
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)
}
}
答案 8 :(得分:4)
// 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];
}
答案 9 :(得分:3)
在swift中
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)}
答案 10 :(得分:3)
扩展了@Nick H247的答案,我遇到了一个问题,首先在旋转时按钮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;
当边界发生变化时,这会强制按钮重绘。
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,首先计算按钮中的行数,然后在每一行而不是底部放一个下划线,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);
}
}
希望此代码可以帮助其他人!
答案 11 :(得分:2)
Nick H247的答案,但Swift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);
}
}
答案 12 :(得分:2)
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,则必须将标题从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
答案 13 :(得分:2)
您可以使用此代码在按钮中添加带间距的下划线。
1 - Interface builder reference
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)
}
答案 14 :(得分:2)
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,但下划线颜色仍为黑色。
答案 15 :(得分:2)
从2019年9月开始在Xcode 10.3中运行的Swift 5.0版本:
extension UIButton {
func underlineText() {
guard let title = title(for: .normal) else { return }
let titleString = NSMutableAttributedString(string: title)
titleString.addAttribute(
.underlineStyle,
value: NSUnderlineStyle.single.rawValue,
range: NSRange(location: 0, length: title.count)
)
setAttributedTitle(titleString, for: .normal)
}
}
要使用它,请先用button.setTitle("Button Title", for: .normal)
设置按钮标题,然后调用button.underlineText()
使该标题带有下划线。
答案 16 :(得分:1)
使用自定义下划线颜色,线宽和间隙的@NickH247's答案的Swift 3版本:
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")
}
}
答案 17 :(得分:1)
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)
}