来个大佬，教教C# 写COM组件时 事件触发的细节

网络上找了一段代码，告诉了怎么定义事件接口，但在组件内部如何触发没说。来个大佬讲下。
namespace Database_COMObject
{
[Guid("6Array4C1820-04B6-4Array88-Array28F-FD858BArray5C880")]
public interface DBCOM_Interface
{
[DispId(1)]
void Init(string userid , string password);
[DispId(2)]
bool ExecuteSelectCommand(string selCommand);
[DispId(3)]
bool NextRow();
[DispId(4)]
void ExecuteNonSelectCommand(string insCommand);
[DispId(5)]
string GetColumnData(int pos);
}
// 事件接口Database_COMObjectEvents
[Guid("47CArray76E0-C208-4740-AC42-41212D3C34F0"),
InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
public interface DBCOM_Events
{
}
[Guid("ArrayE5E5FB2-21ArrayD-4ee7-AB27-E4DBED8E123E"),
ClassInterface(ClassInterfaceType.None),
ComSourceInterfaces(typeof(DBCOM_Events))]
public class DBCOM_Class : DBCOM_Interface
{
private SqlConnection myConnection = null ;
SqlDataReader myReader = null ;
public DBCOM_Class()
{
}
public void Init(string userid , string password)
{
try
{
string myConnectString = "user id="+userid+";password="+password+
";Database=NorthWind;Server=SKYWALKER;Connect Timeout=30";
myConnection = new SqlConnection(myConnectString);
myConnection.Open();
MessageBox.Show("CONNECTED");
}
catch(Exception e)
{
MessageBox.Show(e.Message);
}
}
public bool ExecuteSelectCommand(string selCommand)
{
if ( myReader != null )
myReader.Close() ;
SqlCommand myCommand = new SqlCommand(selCommand);
myCommand.Connection = myConnection;
myCommand.ExecuteNonQuery();
myReader = myCommand.ExecuteReader();
return true ;
}
public bool NextRow()
{
if ( ! myReader.Read() )
{
myReader.Close();
return false ;
}
return true ;
}
public string GetColumnData(int pos)
{
Object obj = myReader.GetValue(pos);
if ( obj == null ) return "" ;
return obj.ToString() ;
}
public void ExecuteNonSelectCommand(string insCommand)
{
SqlCommand myCommand = new SqlCommand(insCommand , myConnection);
int retRows = myCommand.ExecuteNonQuery();
}
}
}