我正在尝试使用名为 Data.plist 的文件来存储一些简单的非结构化数据,并将此文件放在我的应用程序的根文件夹中。为了便于读/写此文件,我创建了以下 DataManager 结构。它可以读取Data.plist文件没有问题,但它无法将数据写入文件。我不确定问题出在哪里,有人可以发现可能出错的地方吗?
struct DataManager {
static var shared = DataManager()
var dataFilePath: String? {
return Bundle.main.path(forResource: "Data", ofType: "plist")
}
var dict: NSMutableDictionary? {
guard let filePath = self.dataFilePath else { return nil }
return NSMutableDictionary(contentsOfFile: filePath)
}
let fileManager = FileManager.default
fileprivate init() {
guard let path = dataFilePath else { return }
guard fileManager.fileExists(atPath: path) else {
fileManager.createFile(atPath: path, contents: nil, attributes: nil) // create the file
print("created Data.plist file successfully")
return
}
}
func save(_ value: Any, for key: String) -> Bool {
guard let dict = dict else { return false }
dict.setObject(value, forKey: key as NSCopying)
dict.write(toFile: dataFilePath!, atomically: true)
// confirm
let resultDict = NSMutableDictionary(contentsOfFile: dataFilePath!)
print("saving, dict: \(resultDict)") // I can see this is working
return true
}
func delete(key: String) -> Bool {
guard let dict = dict else { return false }
dict.removeObject(forKey: key)
return true
}
func retrieve(for key: String) -> Any? {
guard let dict = dict else { return false }
return dict.object(forKey: key)
}
}
答案 0 :(得分:1)
您无法修改应用包内的文件。因此,Bundle.main.path(forResource:ofType:)
获得的所有文件都是可读的,但不可写。
如果您想修改此文件,则需要先将其复制到应用程序的文档目录中。
let initialFileURL = URL(fileURLWithPath: Bundle.main.path(forResource: "Data", ofType: "plist")!)
let documentDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).last!
let writableFileURL = documentDirectoryURL.appendingPathComponent("Data.plist", isDirectory: false)
do {
try FileManager.default.copyItem(at: initialFileURL, to: writableFileURL)
} catch {
print("Copying file failed with error : \(error)")
}
// You can modify the file at writableFileURL