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
Drop-in解决方案作为UILabel上的一个类别(这假设你的UILabel使用一个带有NSLinkAttributeName属性的带属性字符串):
@implementation UILabel (Support)
- (BOOL)openTappedLinkAtLocation:(CGPoint)location {
CGSize labelSize = self.bounds.size;
NSTextContainer* textContainer = [[NSTextContainer alloc] initWithSize:CGSizeZero];
textContainer.lineFragmentPadding = 0.0;
textContainer.lineBreakMode = self.lineBreakMode;
textContainer.maximumNumberOfLines = self.numberOfLines;
textContainer.size = labelSize;
NSLayoutManager* layoutManager = [[NSLayoutManager alloc] init];
[layoutManager addTextContainer:textContainer];
NSTextStorage* textStorage = [[NSTextStorage alloc] initWithAttributedString:self.attributedText];
[textStorage addAttribute:NSFontAttributeName value:self.font range:NSMakeRange(0, textStorage.length)];
[textStorage addLayoutManager:layoutManager];
CGRect textBoundingBox = [layoutManager usedRectForTextContainer: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(location.x - textContainerOffset.x, location.y - textContainerOffset.y);
NSInteger indexOfCharacter = [layoutManager characterIndexForPoint:locationOfTouchInTextContainer inTextContainer:textContainer fractionOfDistanceBetweenInsertionPoints:nullptr];
if (indexOfCharacter >= 0) {
NSURL* url = [textStorage attribute:NSLinkAttributeName atIndex:indexOfCharacter effectiveRange:nullptr];
if (url) {
[[UIApplication sharedApplication] openURL:url];
return YES;
}
}
return NO;
}
@end
其他回答
NSString *string = name;
NSError *error = NULL;
NSDataDetector *detector =
[NSDataDetector dataDetectorWithTypes:(NSTextCheckingTypes)NSTextCheckingTypeLink | NSTextCheckingTypePhoneNumber
error:&error];
NSArray *matches = [detector matchesInString:string
options:0
range:NSMakeRange(0, [string length])];
for (NSTextCheckingResult *match in matches)
{
if (([match resultType] == NSTextCheckingTypePhoneNumber))
{
NSString *phoneNumber = [match phoneNumber];
NSLog(@" Phone Number is :%@",phoneNumber);
label.enabledTextCheckingTypes = NSTextCheckingTypePhoneNumber;
}
if(([match resultType] == NSTextCheckingTypeLink))
{
NSURL *email = [match URL];
NSLog(@"Email is :%@",email);
label.enabledTextCheckingTypes = NSTextCheckingTypeLink;
}
if (([match resultType] == NSTextCheckingTypeLink))
{
NSURL *url = [match URL];
NSLog(@"URL is :%@",url);
label.enabledTextCheckingTypes = NSTextCheckingTypeLink;
}
}
label.text =name;
}
下面是超链接UILabel的示例代码: 来源:http://sickprogrammersarea.blogspot.in/2014/03/adding-links-to-uilabel.html
#import "ViewController.h"
#import "TTTAttributedLabel.h"
@interface ViewController ()
@end
@implementation ViewController
{
UITextField *loc;
TTTAttributedLabel *data;
}
- (void)viewDidLoad
{
[super viewDidLoad];
UILabel *lbl = [[UILabel alloc] initWithFrame:CGRectMake(5, 20, 80, 25) ];
[lbl setText:@"Text:"];
[lbl setFont:[UIFont fontWithName:@"Verdana" size:16]];
[lbl setTextColor:[UIColor grayColor]];
loc=[[UITextField alloc] initWithFrame:CGRectMake(4, 20, 300, 30)];
//loc.backgroundColor = [UIColor grayColor];
loc.borderStyle=UITextBorderStyleRoundedRect;
loc.clearButtonMode=UITextFieldViewModeWhileEditing;
//[loc setText:@"Enter Location"];
loc.clearsOnInsertion = YES;
loc.leftView=lbl;
loc.leftViewMode=UITextFieldViewModeAlways;
[loc setDelegate:self];
[self.view addSubview:loc];
[loc setRightViewMode:UITextFieldViewModeAlways];
CGRect frameimg = CGRectMake(110, 70, 70,30);
UIButton *srchButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
srchButton.frame=frameimg;
[srchButton setTitle:@"Go" forState:UIControlStateNormal];
[srchButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
srchButton.backgroundColor=[UIColor clearColor];
[srchButton addTarget:self action:@selector(go:) forControlEvents:UIControlEventTouchDown];
[self.view addSubview:srchButton];
data = [[TTTAttributedLabel alloc] initWithFrame:CGRectMake(5, 120,self.view.frame.size.width,200) ];
[data setFont:[UIFont fontWithName:@"Verdana" size:16]];
[data setTextColor:[UIColor blackColor]];
data.numberOfLines=0;
data.delegate = self;
data.enabledTextCheckingTypes=NSTextCheckingTypeLink|NSTextCheckingTypePhoneNumber;
[self.view addSubview:data];
}
- (void)attributedLabel:(TTTAttributedLabel *)label didSelectLinkWithURL:(NSURL *)url
{
NSString *val=[[NSString alloc]initWithFormat:@"%@",url];
if ([[url scheme] hasPrefix:@"mailto"]) {
NSLog(@" mail URL Selected : %@",url);
MFMailComposeViewController *comp=[[MFMailComposeViewController alloc]init];
[comp setMailComposeDelegate:self];
if([MFMailComposeViewController canSendMail])
{
NSString *recp=[[val substringToIndex:[val length]] substringFromIndex:7];
NSLog(@"Recept : %@",recp);
[comp setToRecipients:[NSArray arrayWithObjects:recp, nil]];
[comp setSubject:@"From my app"];
[comp setMessageBody:@"Hello bro" isHTML:NO];
[comp setModalTransitionStyle:UIModalTransitionStyleCrossDissolve];
[self presentViewController:comp animated:YES completion:nil];
}
}
else{
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:val]];
}
}
-(void)mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error{
if(error)
{
UIAlertView *alrt=[[UIAlertView alloc]initWithTitle:@"Erorr" message:@"Some error occureed" delegate:nil cancelButtonTitle:@"" otherButtonTitles:nil, nil];
[alrt show];
[self dismissViewControllerAnimated:YES completion:nil];
}
else{
[self dismissViewControllerAnimated:YES completion:nil];
}
}
- (void)attributedLabel:(TTTAttributedLabel *)label didSelectLinkWithPhoneNumber:(NSString *)phoneNumber
{
NSLog(@"Phone Number Selected : %@",phoneNumber);
UIDevice *device = [UIDevice currentDevice];
if ([[device model] isEqualToString:@"iPhone"] ) {
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:[NSString stringWithFormat:@"tel:%@",phoneNumber]]];
} else {
UIAlertView *Notpermitted=[[UIAlertView alloc] initWithTitle:@"Alert" message:@"Your device doesn't support this feature." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[Notpermitted show];
}
}
-(void)go:(id)sender
{
[data setText:loc.text];
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
NSLog(@"Reached");
[loc resignFirstResponder];
}
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/"]];
}
}
以下是基于@Luca Davanzo的回答,重写touchesBegan事件而不是轻触手势:
import UIKit
public protocol TapableLabelDelegate: NSObjectProtocol {
func tapableLabel(_ label: TapableLabel, didTapUrl url: String, atRange range: NSRange)
}
public class TapableLabel: UILabel {
private var links: [String: NSRange] = [:]
private(set) var layoutManager = NSLayoutManager()
private(set) var textContainer = NSTextContainer(size: CGSize.zero)
private(set) var textStorage = NSTextStorage() {
didSet {
textStorage.addLayoutManager(layoutManager)
}
}
public weak var delegate: TapableLabelDelegate?
public override var attributedText: NSAttributedString? {
didSet {
if let attributedText = attributedText {
textStorage = NSTextStorage(attributedString: attributedText)
} else {
textStorage = NSTextStorage()
links = [:]
}
}
}
public override var lineBreakMode: NSLineBreakMode {
didSet {
textContainer.lineBreakMode = lineBreakMode
}
}
public override var numberOfLines: Int {
didSet {
textContainer.maximumNumberOfLines = numberOfLines
}
}
public override init(frame: CGRect) {
super.init(frame: frame)
setup()
}
public required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setup()
}
public override func layoutSubviews() {
super.layoutSubviews()
textContainer.size = bounds.size
}
/// addLinks
///
/// - Parameters:
/// - text: text of link
/// - url: link url string
public func addLink(_ text: String, withURL url: String) {
guard let theText = attributedText?.string as? NSString else {
return
}
let range = theText.range(of: text)
guard range.location != NSNotFound else {
return
}
links[url] = range
}
private func setup() {
isUserInteractionEnabled = true
layoutManager.addTextContainer(textContainer)
textContainer.lineFragmentPadding = 0
textContainer.lineBreakMode = lineBreakMode
textContainer.maximumNumberOfLines = numberOfLines
}
public override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
guard let locationOfTouch = touches.first?.location(in: self) else {
return
}
textContainer.size = bounds.size
let indexOfCharacter = layoutManager.glyphIndex(for: locationOfTouch, in: textContainer)
for (urlString, range) in links {
if NSLocationInRange(indexOfCharacter, range), let url = URL(string: urlString) {
delegate?.tapableLabel(self, didTapUrl: urlString, atRange: range)
}
}
}}
斯威夫特5.2
我在之前的回答中发现了多行文本标签的几个问题,所以我给出了我最终的工作解决方案。
它解决了多行和文本对齐的问题。
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 textStorage = NSTextStorage(attributedString: label.attributedText!)
// Configure layoutManager and textStorage
layoutManager.addTextContainer(textContainer)
textStorage.addLayoutManager(layoutManager)
// Configure textContainer
textContainer.lineFragmentPadding = 0.0
textContainer.lineBreakMode = label.lineBreakMode
textContainer.maximumNumberOfLines = label.numberOfLines
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 textAligmentOffset = aligmentOffset(for: label)
let textContainerOffset = CGPoint(x: (labelSize.width - textBoundingBox.size.width) * textAligmentOffset - textBoundingBox.origin.x,
y: (labelSize.height - textBoundingBox.size.height) * textAligmentOffset - textBoundingBox.origin.y)
let locationOfTouchInTextContainer = CGPoint(x: (locationOfTouchInLabel.x - textContainerOffset.x),
y: 0 )
// Adjust for multiple lines of text
let lineModifier = Int(floor(locationOfTouchInLabel.y / label.font.lineHeight)) - 1
let rightMostFirstLinePoint = CGPoint(x: labelSize.width,
y: 0)
let charsPerLine = layoutManager.characterIndex(for: rightMostFirstLinePoint, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
let indexOfCharacter = layoutManager.characterIndex(for: locationOfTouchInTextContainer, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
let adjustedRange = indexOfCharacter + (lineModifier * charsPerLine)
return NSLocationInRange(adjustedRange, targetRange)
}
private func aligmentOffset(for label: UILabel) -> CGFloat {
switch label.textAlignment {
case .left, .natural, .justified:
return 0.0
case .center:
return 0.5
case .right:
return 1.0
@unknown default:
return 0.0
}
}
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