我使用textView(_: shouldChangeTextIn: replacementText:)
函数来根据情况更改输入数据。我使用范围,但在使用unicode字符符号(例如(͡°͜ʖ͡°) )时,我无法获得Swift范围。请告诉我怎么做?
func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
let maxLenthNotReached = textView.text.count + (text.count - range.length) <= maxTextLength
if maxLenthNotReached {
guard let newRange = Range(range, in: identityString) else { return false }
identityString = identityString.replacingCharacters(in: newRange, with: text)
}
return maxLenthNotReached
}
应用程序崩溃示例http://take.ms/ojIJq
更新:我更改了此方法,但在删除时再次崩溃
"entering data" ""
"testString" "༼ つ ͡° ͜ʖ ͡° ༽つ( ͡° ͜ʖ ͡"
"entering data" ""
func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
debugPrint("textView.text", textView.text)
testString = textView.text.replacingCharacters(in: Range(range, in: textView.text)!, with: text)//
debugPrint("testString", testString)
return true
}
更新1:我在textView中输入了这些字符
( ͡° ͜ʖ ͡°)༼ つ ͡° ͜ʖ ͡° ༽つ
然后我开始删除带右向左的三个字符后,右边的几个符号被° ༽つ
删除了,而车里的emoji已经离开了,那么我就拿不到范围了,因为我放了守卫,应用程序不会崩溃,如果我删除了,当然会有应用程序崩溃。
完整代码
class ViewController: UIViewController {
// MARK: - IBOutlets
@IBOutlet private weak var textView: UITextView! {
didSet {
textView.delegate = self
textView.text = "( ͡° ͜ʖ ͡°)༼ つ ͡° ͜ʖ ͡° ༽つ"
}
}
// MARK: - Properties
private var testString = ""
}
extension ViewController: UITextViewDelegate {
func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
guard let newRange = Range(range, in: textView.text) else {
return false
}
testString = textView.text.replacingCharacters(in: newRange, with: text)
return true
}
}
更新2:在与Martin交谈后,我发现并提供了一个细节,即这个问题只在键盘上发生,而默认键盘则一切正常。
我的原始行是"( ͡° ͜ʖ ͡°)༼ つ ͡° ͜ʖ ͡° ༽つ”
,此行用于example.If我从左到右删除此行,应用程序崩溃,马丁要求在应用程序崩溃前在控制台中显示最新数据,崩溃前的最后一次打印是textView" "( ͡° ͜ʖ ͡°)༼ つ ͡° ͜ʖ ͡" "range" {27, 1}
发布于 2018-06-08 05:56:15
正如在讨论中所发现的:
textView.text = "(͡°͜ʖ͡°)༼つ͡°͜ʖ͡“range ={ 27,1}
让newRange =range(范围,单位: textView.text)
返回nil
.
原因是范围指向字符的“中间”,该字符存储为UTF-16代理项对。以下是一个简化的自包含示例:
let text = "Hello !"
let range = NSRange(location: 7, length: 1)
let newRange = Range(range, in: text)
print(newRange as Any) // nil
这看起来像是一个bug (在Google键盘上?)对我来说,但有一个可能的解决办法。
“诀窍”是确定“组合字符序列”的最接近的周围范围,下面是如何做到这一点的(比较From any UTF-16 offset, find the corresponding String.Index that lies on a Character boundary):
extension String {
func safeRange(from nsRange: NSRange) -> Range<String.Index>? {
guard nsRange.location >= 0 && nsRange.location <= utf16.count else { return nil }
guard nsRange.length >= 0 && nsRange.location + nsRange.length <= utf16.count else { return nil }
let from = String.Index(encodedOffset: nsRange.location)
let to = String.Index(encodedOffset: nsRange.location + nsRange.length)
return rangeOfComposedCharacterSequences(for: from..<to)
}
}
现在
let newRange = textView.text.safeRange(from: range)
返回将整个字符括起来的String
范围。在我们的简化示例中:
let text = "Hello !"
let range = NSRange(location: 7, length: 1)
let newRange = text.safeRange(from: range)
print(newRange as Any) // Optional(Range(...))
print(text.replacingCharacters(in: newRange!, with: "")) // Hello !
https://stackoverflow.com/questions/50721378
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