swift - NSFileManager 文件存在于路径 :isDirectory and swift

Question

我试图理解如何在 Swift 中使用函数 fileExistsAtPath:isDirectory: 但我完全迷失了。

这是我的代码示例:

var b:CMutablePointer<ObjCBool>?

if (fileManager.fileExistsAtPath(fullPath, isDirectory:b! )){
    // how can I use the "b" variable?!
    fileManager.createDirectoryAtURL(dirURL, withIntermediateDirectories: false, attributes: nil, error: nil)
}

我不明白如何访问 b MutablePointer 的值。如果我想知道它是设置为 YES 还是 NO 怎么办？

Answer 1

second parameter类型为 UnsafeMutablePointer<ObjCBool> ， 意思就是你必须传递 ObjCBool 的地址多变的。示例:

var isDir : ObjCBool = false
if fileManager.fileExistsAtPath(fullPath, isDirectory:&isDir) {
    if isDir {
        // file exists and is a directory
    } else {
        // file exists and is not a directory
    }
} else {
    // file does not exist
}

Swift 3 和 Swift 4 更新:

let fileManager = FileManager.default
var isDir : ObjCBool = false
if fileManager.fileExists(atPath: fullPath, isDirectory:&isDir) {
    if isDir.boolValue {
        // file exists and is a directory
    } else {
        // file exists and is not a directory
    }
} else {
    // file does not exist
}