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
UIButtonTypeCustom是一个可点击的标签,如果你没有为它设置任何图像。
其他回答
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
我创建了一个名为ResponsiveLabel的UILabel子类,它是基于ios7中引入的textkit API。它使用了NAlexN建议的相同方法。它提供了在文本中指定搜索模式的灵活性。可以指定应用于这些模式的样式,以及在敲击模式时要执行的操作。
//Detects email in text
NSString *emailRegexString = @"[A-Z0-9._%+-]+@[A-Z0-9.-]+\\.[A-Z]{2,4}";
NSError *error;
NSRegularExpression *regex = [[NSRegularExpression alloc]initWithPattern:emailRegexString options:0 error:&error];
PatternDescriptor *descriptor = [[PatternDescriptor alloc]initWithRegex:regex withSearchType:PatternSearchTypeAll withPatternAttributes:@{NSForegroundColorAttributeName:[UIColor redColor]}];
[self.customLabel enablePatternDetection:descriptor];
如果你想让一个字符串可点击,你可以这样做。这段代码将属性应用到字符串“text”的每个出现处。
PatternTapResponder tapResponder = ^(NSString *string) {
NSLog(@"tapped = %@",string);
};
[self.customLabel enableStringDetection:@"text" withAttributes:@{NSForegroundColorAttributeName:[UIColor redColor],
RLTapResponderAttributeName: tapResponder}];
这是一个Objective-C类别,它支持现有UILabel中的可点击链接。attributedText字符串,利用现有的NSLinkAttributeName属性。
@interface UILabel (GSBClickableLinks) <UIGestureRecognizerDelegate>
@property BOOL enableLinks;
@end
#import <objc/runtime.h>
static const void *INDEX;
static const void *TAP;
@implementation UILabel (GSBClickableLinks)
- (void)setEnableLinks:(BOOL)enableLinks
{
UITapGestureRecognizer *tap = objc_getAssociatedObject(self, &TAP); // retreive tap
if (enableLinks && !tap) { // add a gestureRegonzier to the UILabel to detect taps
tap = [UITapGestureRecognizer.alloc initWithTarget:self action:@selector(openLink)];
tap.delegate = self;
[self addGestureRecognizer:tap];
objc_setAssociatedObject(self, &TAP, tap, OBJC_ASSOCIATION_RETAIN_NONATOMIC); // save tap
}
self.userInteractionEnabled = enableLinks; // note - when false UILAbel wont receive taps, hence disable links
}
- (BOOL)enableLinks
{
return (BOOL)objc_getAssociatedObject(self, &TAP); // ie tap != nil
}
// First check whether user tapped on a link within the attributedText of the label.
// If so, then the our label's gestureRecogizer will subsequently fire, and open the corresponding NSLinkAttributeName.
// If not, then the tap will get passed along, eg to the enclosing UITableViewCell...
// Note: save which character in the attributedText was clicked so that we dont have to redo everything again in openLink.
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
if (gestureRecognizer != objc_getAssociatedObject(self, &TAP)) return YES; // dont block other gestures (eg swipe)
// Re-layout the attributedText to find out what was tapped
NSTextContainer *textContainer = [NSTextContainer.alloc initWithSize:self.frame.size];
textContainer.lineFragmentPadding = 0;
textContainer.maximumNumberOfLines = self.numberOfLines;
textContainer.lineBreakMode = self.lineBreakMode;
NSLayoutManager *layoutManager = NSLayoutManager.new;
[layoutManager addTextContainer:textContainer];
NSTextStorage *textStorage = [NSTextStorage.alloc initWithAttributedString:self.attributedText];
[textStorage addLayoutManager:layoutManager];
NSUInteger index = [layoutManager characterIndexForPoint:[gestureRecognizer locationInView:self]
inTextContainer:textContainer
fractionOfDistanceBetweenInsertionPoints:NULL];
objc_setAssociatedObject(self, &INDEX, @(index), OBJC_ASSOCIATION_RETAIN_NONATOMIC); // save index
return (BOOL)[self.attributedText attribute:NSLinkAttributeName atIndex:index effectiveRange:NULL]; // tapped on part of a link?
}
- (void)openLink
{
NSUInteger index = [objc_getAssociatedObject(self, &INDEX) unsignedIntegerValue]; // retrieve index
NSURL *url = [self.attributedText attribute:NSLinkAttributeName atIndex:index effectiveRange:NULL];
if (url && [UIApplication.sharedApplication canOpenURL:url]) [UIApplication.sharedApplication openURL:url];
}
@end
这将通过一个UILabel子类(即没有objc_getAssociatedObject的混乱)来完成,但如果你像我一样,你更喜欢避免不必要的(第三方)子类,只是为了给现有的UIKit类添加一些额外的功能。此外,这有一个漂亮的地方,它添加了任何现有的UILabel的点击链接,例如现有的UITableViewCells!
我已经试着让它尽可能的最小化侵入性通过使用现有的NSLinkAttributeName属性在NSAttributedString中已经可用。所以很简单:
NSURL *myURL = [NSURL URLWithString:@"http://www.google.com"];
NSMutableAttributedString *myString = [NSMutableAttributedString.alloc initWithString:@"This string has a clickable link: "];
[myString appendAttributedString:[NSAttributedString.alloc initWithString:@"click here" attributes:@{NSLinkAttributeName:myURL}]];
...
myLabel.attributedText = myString;
myLabel.enableLinks = YES; // yes, that's all! :-)
基本上,它通过添加一个UIGestureRecognizer到你的UILabel来工作。最难的工作是在gestureRecognizerShouldBegin:中完成的,它会重新布局attributedText字符串,以找出被点击的字符。如果这个字符是NSLinkAttributeName的一部分,那么手势识别器将随后触发,检索相应的URL(从NSLinkAttributeName值),并打开每个通常的[UIApplication。sharedApplication openURL:url进程。
注意:通过在gestureRecognizerShouldBegin:中执行所有这些操作,如果你没有碰巧点击标签中的链接,事件就会被传递。因此,例如,你的UITableViewCell将捕获点击链接,但其他行为正常(选择单元格,取消选择,滚动,…)。
我把它放在了GitHub仓库里。 改编自Kai Burghardt的SO帖子。
以下是NAlexN的回答。
class TapabbleLabel: UILabel {
let layoutManager = NSLayoutManager()
let textContainer = NSTextContainer(size: CGSize.zero)
var textStorage = NSTextStorage() {
didSet {
textStorage.addLayoutManager(layoutManager)
}
}
var onCharacterTapped: ((label: UILabel, characterIndex: Int) -> Void)?
let tapGesture = UITapGestureRecognizer()
override var attributedText: NSAttributedString? {
didSet {
if let attributedText = attributedText {
textStorage = NSTextStorage(attributedString: attributedText)
} else {
textStorage = NSTextStorage()
}
}
}
override var lineBreakMode: NSLineBreakMode {
didSet {
textContainer.lineBreakMode = lineBreakMode
}
}
override var numberOfLines: Int {
didSet {
textContainer.maximumNumberOfLines = numberOfLines
}
}
/**
Creates a new view with the passed coder.
:param: aDecoder The a decoder
:returns: the created new view.
*/
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setUp()
}
/**
Creates a new view with the passed frame.
:param: frame The frame
:returns: the created new view.
*/
override init(frame: CGRect) {
super.init(frame: frame)
setUp()
}
/**
Sets up the view.
*/
func setUp() {
userInteractionEnabled = true
layoutManager.addTextContainer(textContainer)
textContainer.lineFragmentPadding = 0
textContainer.lineBreakMode = lineBreakMode
textContainer.maximumNumberOfLines = numberOfLines
tapGesture.addTarget(self, action: #selector(TapabbleLabel.labelTapped(_:)))
addGestureRecognizer(tapGesture)
}
override func layoutSubviews() {
super.layoutSubviews()
textContainer.size = bounds.size
}
func labelTapped(gesture: UITapGestureRecognizer) {
guard gesture.state == .Ended else {
return
}
let locationOfTouch = gesture.locationInView(gesture.view)
let textBoundingBox = layoutManager.usedRectForTextContainer(textContainer)
let textContainerOffset = CGPoint(x: (bounds.width - textBoundingBox.width) / 2 - textBoundingBox.minX,
y: (bounds.height - textBoundingBox.height) / 2 - textBoundingBox.minY)
let locationOfTouchInTextContainer = CGPoint(x: locationOfTouch.x - textContainerOffset.x,
y: locationOfTouch.y - textContainerOffset.y)
let indexOfCharacter = layoutManager.characterIndexForPoint(locationOfTouchInTextContainer,
inTextContainer: textContainer,
fractionOfDistanceBetweenInsertionPoints: nil)
onCharacterTapped?(label: self, characterIndex: indexOfCharacter)
}
}
然后你可以在你的viewDidLoad方法中创建一个类的实例,就像这样:
let label = TapabbleLabel()
label.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(label)
view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|-[view]-|",
options: [], metrics: nil, views: ["view" : label]))
view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|-[view]-|",
options: [], metrics: nil, views: ["view" : label]))
let attributedString = NSMutableAttributedString(string: "String with a link", attributes: nil)
let linkRange = NSMakeRange(14, 4); // for the word "link" in the string above
let linkAttributes: [String : AnyObject] = [
NSForegroundColorAttributeName : UIColor.blueColor(), NSUnderlineStyleAttributeName : NSUnderlineStyle.StyleSingle.rawValue,
NSLinkAttributeName: "http://www.apple.com"]
attributedString.setAttributes(linkAttributes, range:linkRange)
label.attributedText = attributedString
label.onCharacterTapped = { label, characterIndex in
if let attribute = label.attributedText?.attribute(NSLinkAttributeName, atIndex: characterIndex, effectiveRange: nil) as? String,
let url = NSURL(string: attribute) {
UIApplication.sharedApplication().openURL(url)
}
}
最好有一个自定义属性,以便在点击字符时使用。它是NSLinkAttributeName,但可以是任何东西你可以使用那个值去做其他的事情除了打开一个url,你可以做任何自定义动作。
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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