在 UITextView 中更改一个 link 的属性

Question

我有一个带有多个 URL 的 UITextView，我通过将 dataDetectorTypes 属性设置为 UIDataDetectorTypeLink 来激活它们。然后我使用 linkTextAttributes 属性来设置 link 的颜色。现在，当用户点击 link 之一（使用 UITapGestureRecognizer）时，我只想更改 link 的颜色。如果我改变 linkTextAttributes，所有 link 都会改变颜色。

我怎样才能只改变被点击的 link 的颜色？

Answer 1

如果这些网址是固定的。例如：我有以下网址：

我会将它们放入 NSAttributedString 使用 NSMutableAttributedString 将它们全部组合起来

NSMutableAttributedString *urlsAttributedText = [[NSMutableAttributedString alloc]init];

NSAttributedString *url1 = [[NSAttributedString alloc]initWithString:NSLocalizedString(@"http://www.123.com\n", nil) attributes:@{NSForegroundColorAttributeName : [UIColor whiteColor], NSFontAttributeName : [UIFont systemFontOfSize:15.0f]}];

NSAttributedString *url2 = [[NSAttributedString alloc]initWithString:NSLocalizedString(@"http://www.456.com\n", nil) attributes:@{NSForegroundColorAttributeName : [UIColor greenColor], NSFontAttributeName : [UIFont systemFontOfSize:15.0f]}];

NSAttributedString *url3 = [[NSAttributedString alloc]initWithString:NSLocalizedString(@"http://www.789.com\n", nil) attributes:@{NSForegroundColorAttributeName : [UIColor redColor], NSFontAttributeName : [UIFont systemFontOfSize:15.0f]}];

[urlsAttributedText url1];
[urlsAttributedText appendAttributedString:url2];
[urlsAttributedText appendAttributedString:url3];

self.texView.attributedText = urlsAttributedText;

干杯！

Answer 2

我想我解决了它，使用名为 UITextView 的子类，它有一个 rangeOfLink 属性.

首先，在我的 UIViewController viewDidLoad: 中，我添加

self.textView.dataDetectorTypes = UIDataDetectorTypeLink; // change for other link types
self.textView.selectable = YES;
self.textView.userInteractionEnabled = YES;

UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget: self action: @selector(handleTap:)];
tapGesture.cancelsTouchesInView = YES;

[self.textView addGestureRecognizer: tapGesture];
[self.textView setNeedsDisplay]; // force a redraw so that drawRect is called

然后在 handleTap 中，我这样做：

MyTextViewWithLink *aTextView = (IDTextViewWithLink *) recognizer.view;

if (aTextView != self.textView)
    return;

if (recognizer.state == UIGestureRecognizerStateEnded)
{
    CGPoint location = [recognizer locationInView: aTextView];

 // this returns an NSTextCheckingResult if location is inside a link
    NSTextCheckingResult *result = [self textCheckingResultAtPoint: location inTextView: aTextView]; 

    if (result)
    {
        aTextView.rangeOfLink = result.range;
        [aTextView setNeedsDisplay]; // this will force the color change

        // open url
    }
}

最后我在我的 UITextView 子类中覆盖了 drawRect：

self.linkTextAttributes = [NSDictionary dictionary];

NSError *error = nil;
NSDataDetector *dataDetector = [NSDataDetector dataDetectorWithTypes: NSTextCheckingTypeLink error: &error];  // change for other link types

if (!error && dataDetector)
{
    NSArray* resultString = [dataDetector matchesInString: self.text
                                              options: NSMatchingReportProgress
                                                range: NSMakeRange(0, [self.text length])];
    if (resultString.count > 0)
    {
        NSMutableAttributedString *mas = [self.attributedText mutableCopy];

        for (NSTextCheckingResult* result in resultString)
        {
            if (result.resultType == NSTextCheckingTypeLink)
            {
                NSRange intersection = NSIntersectionRange(result.range, self.rangeOfLink);

                if (intersection.length <= 0) // no match
                    [mas addAttribute: NSForegroundColorAttributeName
                                value: [UIColor blueColor]
                                range: self.rangeOfLink];
                else
                    [mas addAttribute: NSForegroundColorAttributeName
                                value: [UIColor redColor]
                                range: self.rangeOfLink];
            }
        }

        self.attributedText = mas;
    }
}

[super drawRect: rect];

现在如果textView有多个link，只有被选中的会改变颜色。

在 UITextView 中更改一个 link 的属性

Change attributes of one link in UITextView

objective-c

uitextview

ios