如何检查在 swift 中声明的 UnsafeMutablePointer<ObjCBool​​> 类型的变量的值？ [复制]

Question

我需要检查从 Swift 中的函数返回的变量的值，该变量的类型为 UnsafeMutablePointer?。

声明如下：

    var isDirectory: UnsafeMutablePointer<ObjCBool>?

当我打印出来时：

    print(isDirectory)

我明白了：

无

我不太擅长将 Swift 与 Objective-C 混合使用。任何帮助将不胜感激。

这是我实际的完整代码：

    let directoryURL: URL = try! FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false)

    let pathOldLocalStorage: String = directoryURL.path + "/OldLocalStorage"

    FileManager.default.createFile(atPath: pathOldLocalStorage, contents: nil, attributes: nil)

    var isDirectory: UnsafeMutablePointer<ObjCBool>?

    let fileExists: Bool = FileManager.default.fileExists(atPath: pathOldLocalStorage, isDirectory: isDirectory)

    print("fileExists=", fileExists, "isDirectory=", isDirectory as Any)

这是调试窗口的结果：

fileExists=true isDirectory=nil

Answer 1

你需要这样称呼它：

var isDirectory: ObjCBool = false

let fileExists: Bool = FileManager.default.fileExists(atPath: pathOldLocalStorage, isDirectory: &isDirectory)

if fileExists {
    print("isDirectory=\(isDirectory)")
}