C#

InitializeGrid()
{
    // Create sample List of custom objects. First object uses a non-default
    // constructor, the second uses the default (no reason, just seemed
    // like something to do in the example).

    List<CustomItem> sourceList = new List<CustomItem>();
    CustomItem firstItem = new CustomItem("Special content");
    sourceList.Add(firstItem);
    CustomItem nextItem = new CustomItem();
    sourceList.Add(nextItem);

    // Create the BindingSource, add the list, and add an event handler
    // for the AddingNew event.

    BindingSource bindingSource = new BindingSource();
    bindingSource.DataSource = sourceList;
    bindingSource.AddingNew += new AddingNewEventHandler(bindingSource_AddingNew);

    // Bind to the DataGridView.

    dataGridView.DataSource = bindingSource;
}

private void bindingSource_AddingNew(object sender, AddingNewEventArgs e)
{
    // Use non-default constructor for the new object that will
    // be the source for the new row.

    e.NewObject = new CustomItem("Not default content");
}

Jason Pease wrote:

it leaks connections like a siv

Jason Pease wrote:

nderscores added for legibility

Guffa wrote:

Of course the behaviour depends on what else is happening in the code. You are never closing the data reader, so it will be depending on garbage collections to finalize it. If there doesn't happen to be a garbage collection soon, it will be leaking the connection.

Guffa wrote:

Perhaps even like a sieve?

Guffa wrote:

So much work for something that didn't end up very good anyway... Use the pre tag instead.

Jason Pease wrote:

The garbage collection doesn't seems to be the issue based on the counters in perfmon, but I'm not sure how reliable they are.

Jason Pease wrote:

Perhaps, you are missing the point.

Jason Pease wrote:

Try to read my initial post again and see you if you can pick out the phrase where I say the code works, and has worked for years, correctly in many parts of the application.

Jason Pease wrote:

If it were simply a question of never closing the data reader it would have leaked connections from day one.

using (SqlConnection myConnection = new SqlConnection(ConfigurationSettings.AppSettings["connectionStringUSR"]))
{
... Do the other database work here...
}

SqlDataReader dr = myCommand.ExecuteReader(CommandBehavior.CloseConnection);
try
{
  if(dr.Read()==true)
  {
    if(dr.IsDBNull(0))
      return -1;
    else
      return dr.GetInt32(0);
  }
  else
  {
    return -1;
  }
}
finally
{
  dr.Close();
}