我有一个麻烦内更新数据库（嵌入式）毛伊岛应用程序，之前我添加existinf文件database.db为我的毛伊岛项目与嵌入式资源。现在我删除此database.db，然后使用FTP服务器下载此database.db，但我的应用程序无法捕获绑定数据。。你可以看到这里（我命名为1.0版）连接sqlite数据库，和我的应用程序捕捉绑定数据很好

public static string DatabasePath => 
   Path.Combine(Environment.GetFolderPath
  (Environment.SpecialFolder.MyDocuments), DatabaseFilename);

private SQLiteConnection _connection;
public SQLiteConnection Connection => _connection ??= new 
       SQLiteConnection(ConstantsInfo.DatabasePath);

public  void Initialize()
  {
    //1.open target file to filestream
    using var dbFileStream = new FileStream(ConstantsInfo.DatabasePath, FileMode.OpenOrCreate);
    //2.open resource file database -->resourcestream
    using var dbAssetStream = typeof(ProdottiStorage)
 .Assembly.GetManifestResourceStream("Dataoffline."+ConstantsInfo.DatabaseFilename);
    //3.copy resource stream to filestream 
    dbAssetStream.CopyTo(dbFileStream);
   }

现在（版本2.0）我想更新我的数据库-> database.db（相同的名称，但不同的数据），所以我删除旧的database.db和下载新的database.db从ftp服务器，代码在这里：

public RelayCommand _yesupdate;
public RelayCommand YesUpdate => _yesupdate ??= new 
RelayCommand(() =>
    {
     // Get the object used to communicate with the server.
      FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://" + ftpInfo.IPV4 + @"/" + ftpInfo.FileName);

     request.Method = WebRequestMethods.Ftp.DownloadFile;
     //login
     request.Credentials = new NetworkCredential(ftpInfo.UseName, ftpInfo.Pwd);

            FtpWebResponse response = (FtpWebResponse)request.GetResponse();

            Stream responseStream = response.GetResponseStream();
            StreamReader reader = new StreamReader(responseStream);
            string content = reader.ReadToEnd();
            content = content.ToUpperInvariant();
            string targetFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Personal), ftpInfo.FileName);
        
            using FileStream outputStream = System.IO.File.OpenWrite(targetFile);
            using StreamWriter streamWriter = new StreamWriter(outputStream);
            streamWriter.Write(content);
           
            Alert.Execute(null);
       
            reader.Close();
            response.Close();

结果是我的APP无法获取数据，但ftp服务器显示我下载成功时，我的android设备无法找到database.db，只能看到一个无效文件（缓存）