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
最简单可靠的方法是使用Kedar Paranjape推荐的UITextView。基于Karl Nosworthy的回答,我最终想出了一个简单的UITextView子类:
class LinkTextView: UITextView, UITextViewDelegate {
typealias Links = [String: String]
typealias OnLinkTap = (URL) -> Bool
var onLinkTap: OnLinkTap?
override init(frame: CGRect, textContainer: NSTextContainer?) {
super.init(frame: frame, textContainer: textContainer)
isEditable = false
isSelectable = true
isScrollEnabled = false //to have own size and behave like a label
delegate = self
}
required init?(coder: NSCoder) {
super.init(coder: coder)
}
func addLinks(_ links: Links) {
guard attributedText.length > 0 else {
return
}
let mText = NSMutableAttributedString(attributedString: attributedText)
for (linkText, urlString) in links {
if linkText.count > 0 {
let linkRange = mText.mutableString.range(of: linkText)
mText.addAttribute(.link, value: urlString, range: linkRange)
}
}
attributedText = mText
}
func textView(_ textView: UITextView, shouldInteractWith URL: URL, in characterRange: NSRange) -> Bool {
return onLinkTap?(URL) ?? true
}
// to disable text selection
func textViewDidChangeSelection(_ textView: UITextView) {
textView.selectedTextRange = nil
}
}
用法非常简单:
let linkTextView = LinkTextView()
let tu = "Terms of Use"
let pp = "Privacy Policy"
linkTextView.text = "Please read the Some Company \(tu) and \(pp)"
linkTextView.addLinks([
tu: "https://some.com/tu",
pp: "https://some.com/pp"
])
linkTextView.onLinkTap = { url in
print("url: \(url)")
return true
}
请注意,isScrollEnabled默认为false,因为在大多数情况下,我们需要有自己大小且没有滚动的类似标签的小视图。如果你想要一个可滚动的文本视图,就把它设为true。
还要注意,UITextView不像UILabel有默认的文本填充。要删除它,使布局与UILabel相同,只需添加:linkTextView。textContainerInset = . 0
实现onLinkTap闭包是不必要的,没有它url是由UIApplication自动打开的。
由于文本选择在大多数情况下是不可取的,但它不能关闭,它在委托方法中被解散(感谢Carson Vo)
其他回答
我强烈建议使用自动检测文本中的url并将其转换为链接的库。 试一试:
TTTAttributedLabel (pod) ZSWTappableLabel (under).
两者都得到了麻省理工学院的许可。
基于Charles Gamble的答案,这是我使用的(我删除了一些让我困惑并给我错误索引的行):
- (BOOL)didTapAttributedTextInLabel:(UILabel *)label inRange:(NSRange)targetRange TapGesture:(UIGestureRecognizer*) gesture{
NSParameterAssert(label != nil);
// create instances of NSLayoutManager, NSTextContainer and NSTextStorage
NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:label.attributedText];
// configure layoutManager and textStorage
[textStorage addLayoutManager:layoutManager];
// configure textContainer for the label
NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:CGSizeMake(label.frame.size.width, label.frame.size.height)];
textContainer.lineFragmentPadding = 0.0;
textContainer.lineBreakMode = label.lineBreakMode;
textContainer.maximumNumberOfLines = label.numberOfLines;
// find the tapped character location and compare it to the specified range
CGPoint locationOfTouchInLabel = [gesture locationInView:label];
[layoutManager addTextContainer:textContainer]; //(move here, not sure it that matter that calling this line after textContainer is set
NSInteger indexOfCharacter = [layoutManager characterIndexForPoint:locationOfTouchInLabel
inTextContainer:textContainer
fractionOfDistanceBetweenInsertionPoints:nil];
if (NSLocationInRange(indexOfCharacter, targetRange)) {
return YES;
} else {
return NO;
}
}
我扩展了@samwize的答案来处理多行UILabel,并给出了一个使用UIButton的例子
extension UITapGestureRecognizer {
func didTapAttributedTextInButton(button: UIButton, inRange targetRange: NSRange) -> Bool {
guard let label = button.titleLabel else { return false }
return didTapAttributedTextInLabel(label, inRange: targetRange)
}
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.locationInView(label)
let textBoundingBox = layoutManager.usedRectForTextContainer(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 locationOfTouchInTextContainer = CGPointMake((locationOfTouchInLabel.x - textContainerOffset.x),
0 );
// Adjust for multiple lines of text
let lineModifier = Int(ceil(locationOfTouchInLabel.y / label.font.lineHeight)) - 1
let rightMostFirstLinePoint = CGPointMake(labelSize.width, 0)
let charsPerLine = layoutManager.characterIndexForPoint(rightMostFirstLinePoint, inTextContainer: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
let indexOfCharacter = layoutManager.characterIndexForPoint(locationOfTouchInTextContainer, inTextContainer: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
let adjustedRange = indexOfCharacter + (lineModifier * charsPerLine)
return NSLocationInRange(adjustedRange, targetRange)
}
}
从iOS 15开始,SwiftUI内置支持Markdown标记语言,因此Markdown中的文本:
Text("You can [click this link](https://www.example.com) to visit the website.")
或者作为一个使用SwiftUI的最简单的例子,你可以这样做:
HStack() {
Text("Open the")
.foregroundColor(.black)
Link(destination: URL(string: "https://www.example.com/TOS.html")!) {
Text("link")
.foregroundColor(.blue)
.underline()
}
Text("in browser")
.foregroundColor(.black)
}
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];
}
推荐文章
- 是否有可能更新一个本地化的故事板的字符串?
- 以编程方式获取Bundle Identifier
- 为iPad和iPhone设计输入按钮
- 如何在我的iPhone应用程序中使用NSError ?
- 我的预发行应用已经在iTunes Connect中“处理”了一周多,这是怎么回事?
- Xcode iOS项目只显示“我的Mac 64位”,但不显示模拟器或设备
- Objective-C中的自动引用计数不能防止或减少什么样的泄漏?
- 在Xcode 9中如何从打开的多个模拟器中退出或关闭单个模拟器?
- 如何使用Swift播放声音?
- UINavigationBar自定义返回按钮没有标题
- 如何精确地以毫秒为单位记录方法的执行时间?
- 在整个UIWindow中获取UIView的位置
- 如何解散ViewController在Swift?
- 如何创建在移动设备上呼叫电话号码的超链接?
- 保存字符串到NSUserDefaults?