Automate COM Object Memory Management

Related Topics

See Free COM Object in VBUC Upgrade Options

Visual Basic 6 will automatically release COM objects when they are not referenced any more.

.NET automatically handles managed resources but does not release all resources immediately. This difference can cause unexpected behaviors. For example, ADO Connections might remain open longer than in VB6.

This optional feature will generate explicit code to achieve the same behavior.

VB6 Code

Private Sub Command2_Click()
    Set conn = CreateObject("ADODB.Connection")
    conn.Open "northwind.mdb"
    Set rs = CreateObject("ADODB.recordset")
    rs.Open "Customers", conn
End Sub

.NET Code

private void  Command2_Click( Object eventSender,  EventArgs eventArgs)
{
      ADODB.Connection conn = null;
      ADODB.Recordset rs = null;
      try
     {
          conn = new ADODB.Connection();
          conn.Open("northwind.mdb", "", "", -1);
          rs = new ADODB.Recordset();
          rs.Open("Customers", conn, ADODB.CursorTypeEnum.adOpenUnspecified,      
                        ADODB.LockTypeEnum.adLockUnspecified, -1);
     }
finally
          MemoryHelper.ReleaseAndCleanObject(rs);
          rs = null;
          MemoryHelper.ReleaseAndCleanObject(conn);
          conn = null;
    }
}