-1
我的下面代码崩溃:范围功能和崩溃在迅速3
func getrange(_ from: Int, length: Int) -> Range<String.Index>? {
guard let fromU16 = utf16.index(utf16.startIndex, offsetBy: from, limitedBy: utf16.endIndex), fromU16 != utf16.endIndex else {
return nil ----->crashes here
}
let toU16 = utf16.index(fromU16, offsetBy: length, limitedBy: utf16.endIndex) ?? utf16.endIndex
guard let from = String.Index(fromU16, within: self),
let to = String.Index(toU16, within: self) else { return nil }
return from ..< to
}
此代码与迅速3迁移崩溃。
有人可以帮助调试问题。
Below is the sequence of events:
//input for below function is: text “123456789”, string “0”, nsrange = location =9, length=0
1)函数1
static func numericText(_ text: String, replacedBy string: String, in nsrange: NSRange) -> String {
guard let range = text.range(for: nsrange) else {
//assertionFailure("Should never reach here")
return text.numericString()
}
// Apply Replacement String to the textField text and extract only the numeric values
return text.replacingCharacters(in: range, with: string)
.numericString()
}
2)函数2
func range(for nsrange: NSRange) -> Range<String.Index>? {
return range(nsrange.location, length: nsrange.length)
}
3)功能3
func range(_ from: Int, length: Int) -> Range<String.Index>? {
guard let fromU16 = utf16.index(utf16.startIndex, offsetBy: from, limitedBy: utf16.endIndex), fromU16 != utf16.endIndex else {
return nil
}
let toU16 = utf16.index(fromU16, offsetBy: length, limitedBy: utf16.endIndex) ?? utf16.endIndex
guard let from = String.Index(fromU16, within: self),
let to = String.Index(toU16, within: self) else { return nil }
return from ..< to
}
什么是错误信息? – rmaddy
你能提供更多的代码吗?因为我无法找到'utf16'从哪里来。在'String'的扩展中是这个函数的位置吗?请提供更多详细信息,以便我们可以帮助您。是的范围函数已经从Swift2更改了一些Swift3,Xcode自动转换总是无法正确转换它。 –
@PangHoMing是的这些都是String扩展中的函数。 – user1452936