ios - 如何在更新 iOS 应用程序时保存用户详细信息？

Question

我有两个 sqlite 数据库，即 workout5.sqlite3 和 custom_ios.sqlite3。我在安装时将两个数据库复制到用户目录

if !fileManager.fileExists(atPath: dbPath) {
    let fromPath: String? = Bundle.main.resourcePath?.stringByAppendingPathComponent(fileName as String)
    var error : NSError?
    do {
        try fileManager.copyItem(atPath: fromPath!, toPath: dbPath)
    } 
    catch let error1 as NSError {
        error = error1
    }

    let alert: UIAlertView = UIAlertView()
    if (error != nil) {
        alert.title = "Error Occured"
        alert.message = error?.localizedDescription
    } 
    else {
        alert.title = "Successfully Copy"
        alert.message = "Your database copy successfully"
    }
}

安装时，我检查文件是否存在。但是每次我更新应用程序时，数据库都会被替换。如何解决这个问题？

Answer 1

只有在卸载应用程序时才会删除文档目录。检查路径中是否存在可读文件:isReadableFile(atPath:)。

示例代码如下:

let DBNAME = "myDB.sqlite"
let yourOriginalDatabasePath = URL(fileURLWithPath: Bundle.main.resourcePath ?? "").appendingPathComponent(DBNAME)
let pathsToDocuments = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
let dbPath = URL(fileURLWithPath: pathsToDocuments[0]).appendingPathComponent(DBNAME)
print("dataBasebPath: \(dbPath.absoluteString)")

let isFileExist = FileManager.default.fileExists(atPath: dbPath.absoluteString)
let isReadableFileExist = FileManager.default.isReadableFile(atPath: dbPath.absoluteString)
if !isReadableFileExist && !isFileExist {
     print("[DB] Copying DB to Documents Folder")
     do {
        try FileManager.default.copyItem(at: yourOriginalDatabasePath, to: dbPath)
     } catch {
        print("Fail to copy database from \(yourOriginalDatabasePath) to \(dbPath). Error: \(error)")
     }
}