我知道UITextView默认可以检测到URL,但是如何让它检测到hashtags(#)？
它不需要在键入时检测主题标签,但是然后viewDidLoad文本在UITextView中设置,所以我想将主题标签检测为颜色或其他东西.
我一直在使用ActiveLabel,但这只适用于UILabel,我需要UITextView具有的滚动功能.
解决方法
这应该适合你
>使用任何名称创建一个新的swift文件(UITextViewHashtagExtension.swift)
>在下面插入以下代码：
import UIKit
extension UITextView {
func resolveHashTags(){
// turn string in to NSString
let nsText:NSString = self.text
// this needs to be an array of NSString. String does not work.
let words:[NSString] = nsText.componentsSeparatedByString(" ")
// you can't set the font size in the storyboard anymore,since it gets overridden here.
let attrs = [
NSFontAttributeName : UIFont.systemFontOfSize(17.0)
]
// you can staple URLs onto attributed strings
let attrString = NSMutableAttributedString(string: nsText as String,attributes:attrs)
// tag each word if it has a hashtag
for word in words {
// found a word that is prepended by a hashtag!
// homework for you: implement @mentions here too.
if word.hasPrefix("#") {
// a range is the character position,followed by how many characters are in the word.
// we need this because we staple the "href" to this range.
let matchRange:NSRange = nsText.rangeOfString(word as String)
// convert the word from NSString to String
// this allows us to call "dropFirst" to remove the hashtag
var stringifiedWord:String = word as String
// drop the hashtag
stringifiedWord = String(stringifiedWord.characters.dropFirst())
// check to see if the hashtag has numbers.
// ribl is "#1" shouldn't be considered a hashtag.
let digits = NSCharacterSet.decimalDigitCharacterSet()
if let numbersExist = stringifiedWord.rangeOfCharacterFromSet(digits) {
// hashtag contains a number,like "#1"
// so don't make it clickable
} else {
// set a link for when the user clicks on this word.
// it's not enough to use the word "hash",but you need the url scheme syntax "hash://"
// note: since it's a URL now,the color is set to the project's tint color
attrString.addAttribute(NSLinkAttributeName,value: "hash:\(stringifiedWord)",range: matchRange)
}
}
}
// we're used to textView.text
// but here we use textView.attributedText
// again,this will also wipe out any fonts and colors from the storyboard,// so remember to re-add them in the attrs dictionary above
self.attributedText = attrString
}
}
要使用它,您可以执行以下操作：
self.textView.text = "This is an #example test" self.textView.resolveHashTags()
针对Swift 4.0进行了更新：
extension UITextView {
func resolveHashTags() {
// turn string in to NSString
let nsText = NSString(string: self.text)
// this needs to be an array of NSString. String does not work.
let words = nsText.components(separatedBy: CharacterSet(charactersIn: "#ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_").inverted)
// you can staple URLs onto attributed strings
let attrString = NSMutableAttributedString()
attrString.setAttributedString(self.attributedText)
// tag each word if it has a hashtag
for word in words {
if word.count < 3 {
continue
}
// found a word that is prepended by a hashtag!
// homework for you: implement @mentions here too.
if word.hasPrefix("#") {
// a range is the character position,followed by how many characters are in the word.
// we need this because we staple the "href" to this range.
let matchRange:NSRange = nsText.range(of: word as String)
// drop the hashtag
let stringifiedWord = word.dropFirst()
if let firstChar = stringifiedWord.unicodeScalars.first,NSCharacterSet.decimalDigits.contains(firstChar) {
// hashtag contains a number,like "#1"
// so don't make it clickable
} else {
// set a link for when the user clicks on this word.
// it's not enough to use the word "hash",but you need the url scheme syntax "hash://"
// note: since it's a URL now,the color is set to the project's tint color
attrString.addAttribute(NSAttributedStringKey.link,range: matchRange)
}
}
}
// we're used to textView.text
// but here we use textView.attributedText
// again,// so remember to re-add them in the attrs dictionary above
self.attributedText = attrString
}
}