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

这是沙玛林。基于Kedar的答案的iOS c#实现。

MyClickableTextViewWithCustomUrlScheme实现与ShouldInteractWithUrl覆盖:

// Inspired from https://stackoverflow.com/a/44112932/15186
internal class MyClickableTextViewWithCustomUrlScheme : UITextView, IUITextViewDelegate
{
    public MyClickableTextViewWithCustomUrlScheme()
    {
        Initialize();
    }

    public MyClickableTextViewWithCustomUrlScheme(Foundation.NSCoder coder) : base(coder)
    {
        Initialize();
    }

    public MyClickableTextViewWithCustomUrlScheme(Foundation.NSObjectFlag t) : base(t)
    {
        Initialize();
    }

    public MyClickableTextViewWithCustomUrlScheme(IntPtr handle) : base(handle)
    {
        Initialize();
    }

    public MyClickableTextViewWithCustomUrlScheme(CoreGraphics.CGRect frame) : base(frame)
    {
        Initialize();
    }

    public MyClickableTextViewWithCustomUrlScheme(CoreGraphics.CGRect frame, NSTextContainer textContainer) : base(frame, textContainer)
    {
        Initialize();
    }

    void Initialize()
    {
        Delegate = this;
    }

    [Export("textView:shouldInteractWithURL:inRange:")]
    public new bool ShouldInteractWithUrl(UITextView textView, NSUrl URL, NSRange characterRange)
    {
        if (URL.Scheme.CompareTo(@"username") == 0)
        {
            // Launch the Activity
            return false;
        }
        // The system will handle the URL
        return base.ShouldInteractWithUrl(textView, URL, characterRange);
    }
}

在c#中转换的objective-C代码变成:

MyClickableTextViewWithCustomUrlScheme uiHabitTile = new MyClickableTextViewWithCustomUrlScheme();
uiHabitTile.Selectable = true;
uiHabitTile.ScrollEnabled = false;
uiHabitTile.Editable = false;

// https://stackoverflow.com/a/34014655/15186
string wholeTitle = @"This is an example by marcelofabri";

NSMutableAttributedString attributedString = new NSMutableAttributedString(wholeTitle);
attributedString.AddAttribute(UIStringAttributeKey.Link,
   new NSString("username://marcelofabri"),
   attributedString.Value.RangeOfString(@"marcelofabri")
);
NSMutableDictionary<NSString, NSObject> linkAttributes = new NSMutableDictionary<NSString, NSObject>();
linkAttributes[UIStringAttributeKey.ForegroundColor] = UIColor.Green;
linkAttributes[UIStringAttributeKey.UnderlineColor] = UIColor.LightGray;
linkAttributes[UIStringAttributeKey.UnderlineStyle] = new NSNumber((short)NSUnderlineStyle.PatternSolid);

uiHabitTile.AttributedText = attributedString;

确保将Editable = false和Selectable = true设置为能够单击链接。

同样,ScrollEnabled = true允许textview正确地调整其高度大小。

其他回答

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)

UIButtonTypeCustom是一个可点击的标签,如果你没有为它设置任何图像。

- (BOOL)didTapAttributedTextInLabel:(UILabel *)label inRange:(NSRange)targetRange{
    NSLayoutManager *layoutManager = [NSLayoutManager new];
    NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:CGSizeZero];
    NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:label.attributedText];

    [layoutManager addTextContainer:textContainer];
    [textStorage addLayoutManager:layoutManager];

    textContainer.lineFragmentPadding = 0.0;
    textContainer.lineBreakMode = label.lineBreakMode;
    textContainer.maximumNumberOfLines = label.numberOfLines;
    CGSize labelSize = label.bounds.size;
    textContainer.size = labelSize;

    CGPoint locationOfTouchInLabel = [self locationInView:label];
    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(locationOfTouchInLabel.x - textContainerOffset.x,
                                                         locationOfTouchInLabel.y - textContainerOffset.y);
    NSUInteger indexOfCharacter =[layoutManager characterIndexForPoint:locationOfTouchInTextContainer inTextContainer:textContainer fractionOfDistanceBetweenInsertionPoints:nil];

    return NSLocationInRange(indexOfCharacter, targetRange);
}
    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;
}

老问题,但如果任何人都可以使用UITextView而不是UILabel,那就很容易了。标准网址,电话号码等将自动检测(并可点击)。

然而,如果你需要自定义检测,也就是说,如果你想在用户点击一个特定的单词后能够调用任何自定义方法,你需要使用NSAttributedStrings和一个NSLinkAttributeName属性,它将指向一个自定义URL方案(而不是在默认情况下使用http URL方案)。雷·温德里奇在这里报道

引用上述链接中的代码:

NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:@"This is an example by @marcelofabri_"];
[attributedString addAttribute:NSLinkAttributeName
                     value:@"username://marcelofabri_"
                     range:[[attributedString string] rangeOfString:@"@marcelofabri_"]];

NSDictionary *linkAttributes = @{NSForegroundColorAttributeName: [UIColor greenColor],
                             NSUnderlineColorAttributeName: [UIColor lightGrayColor],
                             NSUnderlineStyleAttributeName: @(NSUnderlinePatternSolid)};

// assume that textView is a UITextView previously created (either by code or Interface Builder)
textView.linkTextAttributes = linkAttributes; // customizes the appearance of links
textView.attributedText = attributedString;
textView.delegate = self;

要检测这些链接点击,实现这个:

- (BOOL)textView:(UITextView *)textView shouldInteractWithURL:(NSURL *)URL inRange:(NSRange)characterRange {
    if ([[URL scheme] isEqualToString:@"username"]) {
        NSString *username = [URL host]; 
        // do something with this username
        // ...
        return NO;
    }
    return YES; // let the system open this URL
}

PS:确保你的UITextView是可选的。