'stringByAppendingPathComponent'不可用

Question

I'm getting the error

'stringByAppendingPathComponent' is unavailable: Use 'stringByAppendingPathComponent' on NSString instead.

when I try to do

let documentsFolder = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as String
let databasePath = documentsFolder.stringByAppendingPathComponent("test.sqlite")

This apparently worked for people before, but it doesn't work for me now in Xcode 7 beta 5.

This thread on the Apple Developer Forums had the suggestion to use an extension or do a direct cast to NSString . But if I do convert it to an NSString

let databasePath = documentsFolder.stringByAppendingPathComponent("test.sqlite" as NSString)

then I get the error

'NSString' is not implicitly convertible to 'String'...

and it gives me the option to "fix-it" by inserting as String , which brings us back to the original error.

This also happens for stringByAppendingPathExtension .

What do I do?

Answer 1

You can create a URL rather rather than a String path.

let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first
let fileURL = documentsURL?.appendingPathComponent("test.sqlite")

If you absolutely need the path, then you can get it like this:

guard let path = fileURL?.path else {
    return
}

print(path) // path will exist at this point

There was some discussion in the thread you mentioned that Apple may be purposely guiding people toward using URLs rather than String paths.

See also:

• What's the difference between path and URL in iOS?
• NSFileManager URL vs Path
• Swift 2.0: Why Guard is Better than If

Answer 2

您可以使用：

let dbPath = (documentsFolder as NSString).stringByAppendingPathComponent("db.sqlite")