swift - 调用中的无关参数标签 'with:'

Question

在这段代码中

text = prospectiveText.substring( with: Range<String.Index>(prospectiveText.startIndex ..< prospectiveText.characters.index(prospectiveText.startIndex, offsetBy: maxLength)) )

我收到错误 Extraneous argument label 'with:' in call在我将 xcode 更新到 10.01 之后

如何修复错误？

Answer 1

如 Cannot invoke initializer for type 'Range<String.Index>' with an argument list of type '(Range<String.Index>)' ，可以通过删除 Range<String.Index>(...) 来修复编译器错误转换。这仍然会引起警告

'characters' is deprecated: Please use String or Substring directly
substring(with:)' is deprecated: Please use String slicing subscript.

可以用

修复

text = prospectiveText[..<prospectiveText.index(prospectiveText.startIndex, offsetBy: maxLength)]

但是，您可以使用

更简单地实现相同的结果

text = String(prospectiveText.prefix(maxLength))