许多应用程序都有文本,文本中是圆角矩形的web超链接,当我点击它们时,UIWebView就会打开。让我困惑的是,他们经常有自定义链接,例如,如果单词以#开头,它也是可点击的,应用程序通过打开另一个视图来响应。我该怎么做呢?是否可以用UILabel或者我需要UITextView或者其他什么?
当前回答
一般来说,如果我们想在UILabel显示的文本中有一个可点击的链接,我们需要解决两个独立的任务:
更改部分文本的外观,使其看起来像链接 检测和处理链接上的触摸(打开URL是一个特殊情况)
第一个很简单。从ios6开始,UILabel支持显示带属性的字符串。你所需要做的就是创建并配置一个NSMutableAttributedString实例:
NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:@"String with a link" attributes:nil];
NSRange linkRange = NSMakeRange(14, 4); // for the word "link" in the string above
NSDictionary *linkAttributes = @{ NSForegroundColorAttributeName : [UIColor colorWithRed:0.05 green:0.4 blue:0.65 alpha:1.0],
NSUnderlineStyleAttributeName : @(NSUnderlineStyleSingle) };
[attributedString setAttributes:linkAttributes range:linkRange];
// Assign attributedText to UILabel
label.attributedText = attributedString;
就是这样!上面的代码使UILabel显示带有链接的String
现在我们应该检测这个链接上的触摸。其思想是捕获UILabel中的所有点击,并确定点击的位置是否足够接近链接。为了捕捉触摸,我们可以在标签中添加点击手势识别器。确保为标签启用userInteraction,默认情况下是关闭的:
label.userInteractionEnabled = YES;
[label addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTapOnLabel:)]];
现在最复杂的事情是:找出点击是否在显示链接的地方,而不是在标签的任何其他部分。如果我们有单行UILabel,这个任务可以通过硬编码链接显示的区域边界来相对容易地解决,但是让我们更优雅地解决这个问题,对于一般情况-多行UILabel,而不需要对链接布局有初步的了解。
其中一种方法是使用iOS 7中引入的Text Kit API功能:
// Create instances of NSLayoutManager, NSTextContainer and NSTextStorage
NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:CGSizeZero];
NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:attributedString];
// Configure layoutManager and textStorage
[layoutManager addTextContainer:textContainer];
[textStorage addLayoutManager:layoutManager];
// Configure textContainer
textContainer.lineFragmentPadding = 0.0;
textContainer.lineBreakMode = label.lineBreakMode;
textContainer.maximumNumberOfLines = label.numberOfLines;
将创建和配置的NSLayoutManager, NSTextContainer和NSTextStorage实例保存在类的属性中(很可能是UIViewController的后代)-我们将在其他方法中需要它们。
现在,每当标签改变它的框架,更新textContainer的大小:
- (void)viewDidLayoutSubviews
{
[super viewDidLayoutSubviews];
self.textContainer.size = self.label.bounds.size;
}
最后,检测点击是否恰好在链接上:
- (void)handleTapOnLabel:(UITapGestureRecognizer *)tapGesture
{
CGPoint locationOfTouchInLabel = [tapGesture locationInView:tapGesture.view];
CGSize labelSize = tapGesture.view.bounds.size;
CGRect textBoundingBox = [self.layoutManager usedRectForTextContainer:self.textContainer];
CGPoint textContainerOffset = CGPointMake((labelSize.width - textBoundingBox.size.width) * 0.5 - textBoundingBox.origin.x,
(labelSize.height - textBoundingBox.size.height) * 0.5 - textBoundingBox.origin.y);
CGPoint locationOfTouchInTextContainer = CGPointMake(locationOfTouchInLabel.x - textContainerOffset.x,
locationOfTouchInLabel.y - textContainerOffset.y);
NSInteger indexOfCharacter = [self.layoutManager characterIndexForPoint:locationOfTouchInTextContainer
inTextContainer:self.textContainer
fractionOfDistanceBetweenInsertionPoints:nil];
NSRange linkRange = NSMakeRange(14, 4); // it's better to save the range somewhere when it was originally used for marking link in attributed string
if (NSLocationInRange(indexOfCharacter, linkRange)) {
// Open an URL, or handle the tap on the link in any other way
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"https://stackoverflow.com/"]];
}
}
其他回答
是的,这是可能的,尽管一开始很困惑。我将进一步向您展示如何甚至可以单击文本中的任何区域。
使用这个方法,你可以有一个UI标签,如下所示:
多行友好 Autoshrink友好 可点击友好型(是的,甚至是单个角色) 斯威夫特5
步骤1:
使UILabel具有'Truncate Tail'的换行属性,并设置最小字体比例。
如果你不熟悉字体比例,请记住以下规则:
minimumFontSize/defaultFontSize = fontscale
在我的例子中,我希望7.2是最小字体大小,而我的起始字体大小是36。因此7.2 / 36 = 0.2
步骤2:
如果你不关心标签是可点击的,只是想要一个工作多行标签你就完成了!
然而,如果你想要标签是可点击阅读…
添加以下扩展我创建
extension UILabel {
func setOptimalFontSize(maxFontSize:CGFloat,text:String){
let width = self.bounds.size.width
var font_size:CGFloat = maxFontSize //Set the maximum font size.
var stringSize = NSString(string: text).size(withAttributes: [.font : self.font.withSize(font_size)])
while(stringSize.width > width){
font_size = font_size - 1
stringSize = NSString(string: text).size(withAttributes: [.font : self.font.withSize(font_size)])
}
self.font = self.font.withSize(font_size)//Forcefully change font to match what it would be graphically.
}
}
它的用法是这样的(只需将<Label>替换为您实际的标签名):
<Label>.setOptimalFontSize(maxFontSize: 36.0, text: formula)
这个扩展是需要的,因为自动收缩不会改变标签的'字体'属性后,它自动收缩,所以你必须通过计算它通过使用.size(withAttributes)函数模拟它的大小将与特定的字体。
这是必要的,因为检测在标签上单击的位置的解决方案需要知道确切的字体大小。
步骤3:
添加以下扩展名:
extension UITapGestureRecognizer {
func didTapAttributedTextInLabel(label: UILabel, inRange targetRange: NSRange) -> Bool {
// Create instances of NSLayoutManager, NSTextContainer and NSTextStorage
let layoutManager = NSLayoutManager()
let textContainer = NSTextContainer(size: CGSize.zero)
let mutableAttribString = NSMutableAttributedString(attributedString: label.attributedText!)
mutableAttribString.addAttributes([NSAttributedString.Key.font: label.font!], range: NSRange(location: 0, length: label.attributedText!.length))
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 6
paragraphStyle.lineBreakMode = .byTruncatingTail
paragraphStyle.alignment = .center
mutableAttribString.addAttributes([.paragraphStyle: paragraphStyle], range: NSMakeRange(0, mutableAttribString.string.count))
let textStorage = NSTextStorage(attributedString: mutableAttribString)
// Configure textContainer
textContainer.lineFragmentPadding = 0.0
textContainer.lineBreakMode = label.lineBreakMode
textContainer.maximumNumberOfLines = label.numberOfLines
// Configure layoutManager and textStorage
layoutManager.addTextContainer(textContainer)
textStorage.addLayoutManager(layoutManager)
let labelSize = label.bounds.size
textContainer.size = labelSize
// Find the tapped character location and compare it to the specified range
let locationOfTouchInLabel = self.location(in: label)
let textBoundingBox = layoutManager.usedRect(for: textContainer)
//let textContainerOffset = CGPointMake((labelSize.width - textBoundingBox.size.width) * 0.5 - textBoundingBox.origin.x,
//(labelSize.height - textBoundingBox.size.height) * 0.5 - textBoundingBox.origin.y);
let textContainerOffset = CGPoint(x: (labelSize.width - textBoundingBox.size.width) * 0.5 - textBoundingBox.origin.x, y: (labelSize.height - textBoundingBox.size.height) * 0.5 - textBoundingBox.origin.y)
//let locationOfTouchInTextContainer = CGPointMake(locationOfTouchInLabel.x - textContainerOffset.x,
// locationOfTouchInLabel.y - textContainerOffset.y);
let locationOfTouchInTextContainer = CGPoint(x: locationOfTouchInLabel.x - textContainerOffset.x, y: locationOfTouchInLabel.y - textContainerOffset.y)
let indexOfCharacter = layoutManager.characterIndex(for: locationOfTouchInTextContainer, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
print("IndexOfCharacter=",indexOfCharacter)
print("TargetRange=",targetRange)
return NSLocationInRange(indexOfCharacter, targetRange)
}
}
您将需要修改这个扩展为您的特定多行情况。在我的例子中,您将注意到我使用了段落样式。
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 6
paragraphStyle.lineBreakMode = .byTruncatingTail
paragraphStyle.alignment = .center
mutableAttribString.addAttributes([.paragraphStyle: paragraphStyle], range: NSMakeRange(0, mutableAttribString.string.count))
确保在扩展中将此更改为您实际使用的行间距,以便一切计算正确。
步骤4:
添加gestureRecognizer到标签在viewDidLoad或你认为合适的地方,就像这样(只需替换< label >与你的标签名再次:
<Label>.addGestureRecognizer(UITapGestureRecognizer(target:self, action: #selector(tapLabel(gesture:))))
这是我的tapLabel函数的一个简化示例(只需将<Label>替换为您的UILabel名称):
@IBAction func tapLabel(gesture: UITapGestureRecognizer) {
guard let text = <Label>.attributedText?.string else {
return
}
let click_range = text.range(of: "(α/β)")
if gesture.didTapAttributedTextInLabel(label: <Label>, inRange: NSRange(click_range!, in: text)) {
print("Tapped a/b")
}else {
print("Tapped none")
}
}
在我的例子中,我的字符串是BED = N * d * [RBE + (d / (α/β))],所以我只是在这种情况下得到α/β的范围。您可以在字符串中添加“\n”以添加换行符和任何您想要的文本,并测试此以在下一行中找到字符串,它仍然会找到它并正确地检测点击!
就是这样!你完成了。享受多行可点击标签。
用下面的.h和.m文件创建类。在.m文件中有以下函数
- (void)linkAtPoint:(CGPoint)location
在这个函数中,我们将检查需要给予操作的子字符串的范围。使用你自己的逻辑来设置你的范围。
下面是子类的用法
TaggedLabel *label = [[TaggedLabel alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
[self.view addSubview:label];
label.numberOfLines = 0;
NSMutableAttributedString *attributtedString = [[NSMutableAttributedString alloc] initWithString : @"My name is @jjpp" attributes : @{ NSFontAttributeName : [UIFont systemFontOfSize:10],}];
//Do not forget to add the font attribute.. else it wont work.. it is very important
[attributtedString addAttribute:NSForegroundColorAttributeName
value:[UIColor redColor]
range:NSMakeRange(11, 5)];//you can give this range inside the .m function mentioned above
下面是.h文件
#import <UIKit/UIKit.h>
@interface TaggedLabel : UILabel<NSLayoutManagerDelegate>
@property(nonatomic, strong)NSLayoutManager *layoutManager;
@property(nonatomic, strong)NSTextContainer *textContainer;
@property(nonatomic, strong)NSTextStorage *textStorage;
@property(nonatomic, strong)NSArray *tagsArray;
@property(readwrite, copy) tagTapped nameTagTapped;
@end
下面是.m文件
#import "TaggedLabel.h"
@implementation TaggedLabel
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self)
{
self.userInteractionEnabled = YES;
}
return self;
}
- (id)initWithCoder:(NSCoder *)aDecoder
{
self = [super initWithCoder:aDecoder];
if (self)
{
self.userInteractionEnabled = YES;
}
return self;
}
- (void)setupTextSystem
{
_layoutManager = [[NSLayoutManager alloc] init];
_textContainer = [[NSTextContainer alloc] initWithSize:CGSizeZero];
_textStorage = [[NSTextStorage alloc] initWithAttributedString:self.attributedText];
// Configure layoutManager and textStorage
[_layoutManager addTextContainer:_textContainer];
[_textStorage addLayoutManager:_layoutManager];
// Configure textContainer
_textContainer.lineFragmentPadding = 0.0;
_textContainer.lineBreakMode = NSLineBreakByWordWrapping;
_textContainer.maximumNumberOfLines = 0;
self.userInteractionEnabled = YES;
self.textContainer.size = self.bounds.size;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
if (!_layoutManager)
{
[self setupTextSystem];
}
// Get the info for the touched link if there is one
CGPoint touchLocation = [[touches anyObject] locationInView:self];
[self linkAtPoint:touchLocation];
}
- (void)linkAtPoint:(CGPoint)location
{
// Do nothing if we have no text
if (_textStorage.string.length == 0)
{
return;
}
// Work out the offset of the text in the view
CGPoint textOffset = [self calcGlyphsPositionInView];
// Get the touch location and use text offset to convert to text cotainer coords
location.x -= textOffset.x;
location.y -= textOffset.y;
NSUInteger touchedChar = [_layoutManager glyphIndexForPoint:location inTextContainer:_textContainer];
// If the touch is in white space after the last glyph on the line we don't
// count it as a hit on the text
NSRange lineRange;
CGRect lineRect = [_layoutManager lineFragmentUsedRectForGlyphAtIndex:touchedChar effectiveRange:&lineRange];
if (CGRectContainsPoint(lineRect, location) == NO)
{
return;
}
// Find the word that was touched and call the detection block
NSRange range = NSMakeRange(11, 5);//for this example i'm hardcoding the range here. In a real scenario it should be iterated through an array for checking all the ranges
if ((touchedChar >= range.location) && touchedChar < (range.location + range.length))
{
NSLog(@"range-->>%@",self.tagsArray[i][@"range"]);
}
}
- (CGPoint)calcGlyphsPositionInView
{
CGPoint textOffset = CGPointZero;
CGRect textBounds = [_layoutManager usedRectForTextContainer:_textContainer];
textBounds.size.width = ceil(textBounds.size.width);
textBounds.size.height = ceil(textBounds.size.height);
if (textBounds.size.height < self.bounds.size.height)
{
CGFloat paddingHeight = (self.bounds.size.height - textBounds.size.height) / 2.0;
textOffset.y = paddingHeight;
}
if (textBounds.size.width < self.bounds.size.width)
{
CGFloat paddingHeight = (self.bounds.size.width - textBounds.size.width) / 2.0;
textOffset.x = paddingHeight;
}
return textOffset;
}
@end
我遵循这个版本,
斯威夫特4:
import Foundation
class AELinkedClickableUILabel: UILabel {
typealias YourCompletion = () -> Void
var linkedRange: NSRange!
var completion: YourCompletion?
@objc func linkClicked(sender: UITapGestureRecognizer){
if let completionBlock = completion {
let textView = UITextView(frame: self.frame)
textView.text = self.text
textView.attributedText = self.attributedText
let index = textView.layoutManager.characterIndex(for: sender.location(in: self),
in: textView.textContainer,
fractionOfDistanceBetweenInsertionPoints: nil)
if linkedRange.lowerBound <= index && linkedRange.upperBound >= index {
completionBlock()
}
}
}
/**
* This method will be used to set an attributed text specifying the linked text with a
* handler when the link is clicked
*/
public func setLinkedTextWithHandler(text:String, link: String, handler: @escaping ()->()) -> Bool {
let attributextText = NSMutableAttributedString(string: text)
let foundRange = attributextText.mutableString.range(of: link)
if foundRange.location != NSNotFound {
self.linkedRange = foundRange
self.completion = handler
attributextText.addAttribute(NSAttributedStringKey.link, value: text, range: foundRange)
self.isUserInteractionEnabled = true
self.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(linkClicked(sender:))))
return true
}
return false
}
}
电话的例子:
button.setLinkedTextWithHandler(text: "This website (stackoverflow.com) is awesome", link: "stackoverflow.com")
{
// show popup or open to link
}
对于完全自定义的链接,你需要使用UIWebView -你可以拦截调用,这样当链接被按下时,你可以转到应用程序的其他部分。
在Swift 3中工作,将整个代码粘贴在这里
//****Make sure the textview 'Selectable' = checked, and 'Editable = Unchecked'
import UIKit
class ViewController: UIViewController, UITextViewDelegate {
@IBOutlet var theNewTextView: UITextView!
override func viewDidLoad() {
super.viewDidLoad()
//****textview = Selectable = checked, and Editable = Unchecked
theNewTextView.delegate = self
let theString = NSMutableAttributedString(string: "Agree to Terms")
let theRange = theString.mutableString.range(of: "Terms")
theString.addAttribute(NSLinkAttributeName, value: "ContactUs://", range: theRange)
let theAttribute = [NSForegroundColorAttributeName: UIColor.blue, NSUnderlineStyleAttributeName: NSUnderlineStyle.styleSingle.rawValue] as [String : Any]
theNewTextView.linkTextAttributes = theAttribute
theNewTextView.attributedText = theString
theString.setAttributes(theAttribute, range: theRange)
}
func textView(_ textView: UITextView, shouldInteractWith URL: URL, in characterRange: NSRange, interaction: UITextItemInteraction) -> Bool {
if (URL.scheme?.hasPrefix("ContactUs://"))! {
return false //interaction not allowed
}
//*** Set storyboard id same as VC name
self.navigationController!.pushViewController((self.storyboard?.instantiateViewController(withIdentifier: "TheLastViewController"))! as UIViewController, animated: true)
return true
}
}
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