我會重用的OracleConnection對象爲多個查詢 所以我寫了一個簡單的類:重用的OracleConnection對象的
public static class DbConnectionsManager
{
/// <summary>
///
/// </summary>
private static OracleConnection _dbConnection = null;
/// <summary>
///
/// </summary>
/// <param name="aConnectionString"></param>
/// <returns></returns>
public static OracleConnection GetDatabaseConnection(string aConnectionString)
{
try
{
if (_dbConnection == null)
{
_dbConnection = new OracleConnection(aConnectionString);
_dbConnection.Open();
return _dbConnection;
}
if (_dbConnection.State == System.Data.ConnectionState.Closed)
{
_dbConnection.ConnectionString = aConnectionString;
_dbConnection.Open();
return _dbConnection;
}
if (!_dbConnection.ConnectionString.Equals(aConnectionString))
{
_dbConnection.Close();
_dbConnection.ConnectionString = aConnectionString;
_dbConnection.Open();
return _dbConnection;
}
return null;
}
catch (Exception e)
{
return null;
}
}
}
這樣我就可以使用連接多次:
using (OracleConnection connection =
DbConnectionsManager.GetDatabaseConnection(aDbConnectionString))
{
OracleCommand command = connection.CreateCommand();
string sql = "SELECT * FROM MYTABLE";
command.CommandText = sql;
OracleDataReader reader = command.ExecuteReader();
while (reader.Read())
{
string myField = (string)reader["EXAMPLE"];
Console.WriteLine(myField);
}
}
當我第一次調用該方法時,一切正常。 如果我記得該方法的靜態對象是!= null,但連接結果關閉! 我從不關閉連接!
當您嘗試重新打開我有這樣的例外
....
if (_dbConnection.State == System.Data.ConnectionState.Closed)
{
_dbConnection.ConnectionString = aConnectionString;
_dbConnection.Open();
return _dbConnection;
}
...
錯誤
Message = "Cannot access a disposed object.\r\nObject name: 'OracleConnection'."