Nlog-动态修改DatabaseTarget，对数据库字符串进行加密

    private static Logger processLogger;  // ① LnProcessDBLog标签 LogManager.GetLogger("LnProcessDBLog");②使用前先保证不为null，否则InitNlog();

    // 修改Nlog.config配置的文件
    private static void InitNlog()
    {
        LoggingConfiguration loggingConfiguration = NLog.LogManager.Configuration;

        var rule = loggingConfiguration.LoggingRules.Where(a => a.LoggerNamePattern == "LnProcessDBLog")?.FirstOrDefault();
        // 方式一：
        //var targetDB = rule.target....FirstOrDefault() ;  // 找到DatabaseTarget；不能转化为DatabaseTarget
        //targetDB.con  // 找不到类型且找到也不可修改，只有get属性
    
        // 方式二：先删除再添加新的
        if (rule != null)
        {
            loggingConfiguration.LoggingRules.Remove(rule);  // 移除原来的DatabaseTarget配置
        }

        var logDatabase = new NLog.Targets.DatabaseTarget("LnProcessDBLog");
        logDatabase.DBProvider = "System.Data.SqlClient";  // 使用的连接类库

        string _connectionString = ConfigurationManager.AppSettings["DefaultConnection"];  // 加密的连接字符串
        logDatabase.ConnectionString = AESEncryptHelper.Decode(_connectionString);  // 解密连接字符串

        logDatabase.CommandType = CommandType.Text;  // 默认为CommandType.Text
        logDatabase.CommandText = @"INSERT INTO [SYS_LOG_DETAILS]([LogDate],[LogThread],[LogLevel],[LogLogger],[LogMessage],[LogActionClick],[UserName],[UserIP],[LogOrder]) VALUES(@LogDate,@LogThread,@LogLevel,@LogLogger,@LogMessage,@LogActionClick,@UserName,@UserIP,@LogOrder)";

        logDatabase.Parameters.Add(new DatabaseParameterInfo() { Name = "@LogDate", Layout = "${event-properties:item=LogDate}" });
        logDatabase.Parameters.Add(new DatabaseParameterInfo() { Name = "@LogThread", Layout = "${event-properties:item=LogThread}" });
        logDatabase.Parameters.Add(new DatabaseParameterInfo() { Name = "@LogLevel", Layout = "${event-properties:item=LogLevel}" });
        logDatabase.Parameters.Add(new DatabaseParameterInfo() { Name = "@LogLogger", Layout = "${event-properties:item=LogLogger}" });
        logDatabase.Parameters.Add(new DatabaseParameterInfo() { Name = "@LogMessage", Layout = "${event-properties:item=LogMessage}" });
        logDatabase.Parameters.Add(new DatabaseParameterInfo() { Name = "@LogActionClick", Layout = "${event-properties:item=LogActionClick}" });
        logDatabase.Parameters.Add(new DatabaseParameterInfo() { Name = "@LogOrder", Layout = "测试" });
        logDatabase.Parameters.Add(new DatabaseParameterInfo() { Name = "@UserName", Layout = "${event-properties:item=UserName}" });
        logDatabase.Parameters.Add(new DatabaseParameterInfo() { Name = "@UserIP", Layout = "${event-properties:item=UserIP}" });

        loggingConfiguration.AddRule(LogLevel.Trace, LogLevel.Fatal, logDatabase, "LnProcessDBLog", true);  // 添加新的DatabaseTarget配置
        NLog.LogManager.Configuration = loggingConfiguration;  // 赋值给NLog.LogManager.Configuration。

        processLogger = LogManager.GetLogger("LnProcessDBLog");  // 重新给全局变量赋值。
    }