Merge pull request #255 from taosdata/ExecuteSubscribe

加入订阅的示例 和孔方法， 后续开始实现。

src/Example/Program.cs

@@ -9,6 +9,7 @@
 using System.Data.Common;
 using System.Linq;
 using System.Net.NetworkInformation;
+using System.Security.Cryptography.X509Certificates;
 using System.Text.Json.Nodes;
 using System.Threading;
 using System.Threading.Tasks;
@@ -82,6 +83,53 @@ private static void Main(string[] args)
  ExecSqlByWebSocket(builder.UseWebSocket());
  UseTaosEFCore(builder.UseWebSocket());
 #endif
+ using (var connection = new TaosConnection(builder.ConnectionString))
+ {
+ try
+ {
+ connection.Open();
+ connection.CreateCommand($"select * from power.meters where current > 10").ExecuteSubscribe("topic-meter-current-bg-10", reader =>
+ {
+ if (reader.HasRows)
+ {
+ while (reader.Read())
+ {
+ Console.WriteLine($"ts:{reader.GetDateTime("ts")} current:{reader.GetDouble("current")} voltage:{reader.GetDouble("voltage")} phase:{reader.GetDouble("phase")} location:{reader.GetDouble("location")} "); ;
+ }
+ }
+ });
+ }
+ catch (Exception ex)
+ {
+ Console.WriteLine("执行TDengine异常" + ex.Message);
+ }
+ finally
+ {
+ connection.Close();
+ }
+ }
+
+
+ using (var connection = new TaosConnection(builder.ConnectionString))
+ {
+ try
+ {
+ connection.Open();
+
+ connection.CreateCommand($"select * from power.meters where current > 10")
+ .ExecuteSubscribe<(DateTime ts, double current, double voltage, double phase, string location)>
+ ("topic-meter-current-bg-10", data => Console.WriteLine($"ts:{data.ts} current:{data.current} voltage:{data.voltage} phase:{data.phase} location:{data.location} "));
+
+ }
+ catch (Exception ex)
+ {
+ Console.WriteLine("执行TDengine异常" + ex.Message);
+ }
+ finally
+ {
+ connection.Close();
+ }
+ }
  }
 
  private static void ExecSqlByNative(TaosConnectionStringBuilder builder)

src/IoTSharp.Data.Taos/TaosCommand.cs

@@ -387,15 +387,37 @@ public override object ExecuteScalar()
  }
  return result;
  }
-
+ /// <summary>
+ /// 订阅数据， 使用 TaosDataReader自行处理数据。 
+ /// </summary>
+ /// <param name="subscribe"></param>
+ /// <returns></returns>
+ /// <exception cref="NotImplementedException"></exception>
+ public bool ExecuteSubscribe(string topic, Action<TaosDataReader> subscribe)
+ {
+ throw new NotImplementedException();
+ }
+ /// <summary>
+ /// 订阅数据， 以对象方式返回。 
+ /// </summary>
+ /// <typeparam name="T"></typeparam>
+ /// <param name="subscribe"></param>
+ /// <returns></returns>
+ /// <exception cref="NotImplementedException"></exception>
+ public bool ExecuteSubscribe<T>(string topic, Action<T> subscribe)
+ {
+ throw new NotImplementedException();
+ }
+
  /// <summary>
  /// Attempts to cancel the execution of the command. Does nothing.
  /// </summary>
  public override void Cancel()
  {
+ //unsubscribe 
  }
 
- 
+
  }
 
 }