DataTable only removes one row?

Question

Can somebody tell me my mistake? I have two Tables, merged in one. They are distinguishable by one column called source. (expected, found) I wan´t to remove all equal rows... But in case of removing both rows, only the row i-1 will be removed...

for (int i = 0; i < tbl.Rows.Count; i++)
            {
                try
                {

                    if (tbl.Rows[i].ItemArray.Contains(Constants.VALUE_SOURCE_FOUND) && tbl.Rows[i - 1].ItemArray.Contains(Constants.VALUE_SOURCE_EXPECTED))
                    {

                        var founded = (tbl.Rows[i].ItemArray).ToArray();
                        var expected = (tbl.Rows[i - 1].ItemArray).ToArray();


                        for (int u = 0; u < founded.Length; u++)
                        {
                            if (founded[u].ToString() == Constants.VALUE_SOURCE_FOUND)
                            {
                                founded = founded.Where(w => w != founded[u]).ToArray();        
                                expected = expected.Where(w => w != expected[u]).ToArray();     
                            }
                        }


                        if (founded.ToString() == expected.ToString())
                        {
                            tbl.Rows[i - 1].Delete();       
                            tbl.AcceptChanges();
                            tbl.Rows[i].Delete();           
                            tbl.AcceptChanges();
                        }

                    }
                }
                catch { }
            }
        }


        return tbl;

You should rather tell us why you think that there is something wrong in that piece of code — Nico Haase, Jan 30 '19 at 11:34
:) `tbl` returns a Table for a DataGrid. The code removes all the right rows from `i-1`, but shows the `i` rows... — Nick S., Jan 30 '19 at 11:36
If you remove `i-1`, then what was at `i` before is now at `i-1` — steve16351, Jan 30 '19 at 11:39

score 0 · Accepted Answer · edited Jan 30 '19 at 14:01

0

Does this work?

tbl.Rows[i].Delete();
tbl.AcceptChanges();

tbl.Rows[i-1].Delete();

tbl.AcceptChanges();

i = i - 2;

As far as i know, delete only "marks" the row as to be deleted, you have to commit it first. With your second call you commit the first one, but the second delete is never executed on the datatable.

edited Jan 30 '19 at 14:01

Nick S.

11
3

answered Jan 30 '19 at 11:45

goetterkomplex

61
3

1

If it would: please add some explanation such that the OP can learn from it – Nico Haase Jan 30 '19 at 11:48
now it deletes every secound simmular row :D wtf i´ve edited my code, can u have a look? – Nick S. Jan 30 '19 at 12:07
Maybe this would be a better solution for you alltogether: https://stackoverflow.com/questions/4415519/best-way-to-remove-duplicate-entries-from-a-data-table – goetterkomplex Jan 30 '19 at 12:31
@goetterkomplex nope, I already tryed everything from this side but thx – Nick S. Jan 30 '19 at 12:47

DataTable only removes one row?

1 Answers1