BindingList for DTO which support object deleted state

Question

I have a BindingList for DTO which can bind directly to window form control and the problem was raised when user want to delete a row in my datagridview.

In that situation, the deleted object (row) go away and when that DTO BindingList get back to server for updating, I dont know which row to delete.

Can a BindingList have a collection for deleted object by default or I have to implement it manually or there is another option for my situation?

Any helps would be appreciated.

Answer 1

The BindingList has a ListChanged event that is raised when the list changes. You would need to write code that handles this event and tracks what items in the list were deleted.

http://msdn.microsoft.com/en-us/library/ms132742.aspx

Another option would be to track the deletes as they happen in the DataGridView.

Answer 2

In my opinion, get data manually with LinQ. Create a DataTable for result like

DataTable dt = new DataTable();

        dt.Columns.Add("Want to Delete?",typeof(bool));
        dt.Columns.Add("Data Id", typeof(string));
        dt.Columns.Add("Data 1", typeof(string));
        dt.AcceptChanges();

        return dt;

then create rows for your result like.

in a loop foreach(var result in myResult)

object[] row = new object[]
        {
        false,
        result.Id,
        result.Data1
        };
        dt.Rows.Add(row);

Let user can choice rows for delete, user can check first column. Because it is bool(checkBox) and after delete button click event, handle selected rows

foreach (DataRow dr in yourDataTable.Rows)
        {
            if (Convert.ToBoolean(dr[0])) // goes in if its checked
            {
                // delete dr[0]
            }
        }

I hope this will help you.