如何将nlog消息存储到sqllite中?使用Xamarin.ios

Question

在xamarin .ios中，我正在使用nlog，因为如果我创建xls file＆amp;存储消息正常工作，但我尝试将其存储到sqllite中。我创建了名为errolog的表，在该表中创建了4列。DatabaseStore到myDocument文件夹中。您可以在代码下方宣布我，什么是问题？

？

private void InitializeNLog()
{
    var saveDir = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
    var documents = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
    _pathToDatabase = Path.Combine(saveDir, "db_sqlite-net.db");
    // Create the database and a table to hold Person information.
    using (var conn= new SQLite.SQLiteConnection(_pathToDatabase))
    {
        conn.CreateTable<ErrorLog>();
    }
    // this coding insert is working but error value not updated
    // var errorlog = new ErrorLog { Time = "${longdate}", Level = "${level}", Lessage ="${message}", Logger = "${logger}" };
    //      
    // using (var db = new SQLite.SQLiteConnection(_pathToDatabase ))
    // {
    //     db.Insert(errorlog);
    // }
    DatabaseTarget target = new DatabaseTarget();
    target.DBProvider = "System.Data.SQLite.SQLiteConnection, System.Data.SQLite, Version=1.0.65.0, Culture=neutral, PublicKeyToken=db937bc2d44ff139";
    target.ConnectionString = "Data Source="+_pathToDatabase+";Version=3;";
    target.CommandText = "insert into ErrorLog( Time,Level,Lessage,Logger) values(@Time,@Level,@Lessage,@Logger)";
    // target.CommandText = "insert into ErrorLog( Time,Level,Lessage,Logger) values
    target.KeepConnection = true;
    target.Parameters.Add(new DatabaseParameterInfo("@Time","${longdate}"));
    target.Parameters.Add(new DatabaseParameterInfo("@Level","${level}"));
    target.Parameters.Add(new DatabaseParameterInfo("@Lessage","${message}"));
    target.Parameters.Add(new DatabaseParameterInfo("@Logger","${logger}"));
    SimpleConfigurator.ConfigureForTargetLogging(target, LogLevel.Info);
    _logger = LogManager.GetCurrentClassLogger ();
    _logger.Info ("Sample informational message");
    // SimpleConfigurator.ConfigureForTargetLogging(
    //     new FileTarget()
    //     {
    //         FileName = Path.Combine(saveDir,"${shortdate}.csv"),
    //         Layout = new CsvLayout()
    //         {
    //             Columns =
    //             {
    //                 new CsvColumn"Time", "${longdate}"),
    //                 new CsvColumn("Level", "${level}"),
    //                 new CsvColumn("Lessage", "${message}"),
    //                 new CsvColumn("Logger", "${logger}")
    //             },
    //         }
    //     },
    //     LogLevel.Info);
}

Answer 1

每次初始化时，您很可能会覆盖数据库。改用此方法：

if (!File.Exists(_pathToDatabase)) {
  using (var conn= new SQLite.SQLiteConnection(_pathToDatabase)) {
    conn.CreateTable<ErrorLog>();
  }
}