Remove last (empty) entry from StringBuilder object, when exporting to CSV

Question

I want to remove the last (empty) row of a StringBuilder Object

EDIT: The empty row is from the "AllowUserToAddRows" how can i skip it?

c# Forms application
dataGridView1 on form2
I want Export to CSV (separated by semicolon) [btw. it's just one column]
It Could happen, that a previously created CSV is parsed to the dataGridView again

I use a altered solution from here: Exporting datagridview to csv file

my code

void SaveDataGridViewToCSV(string filename)
{
    var sb = new StringBuilder();

    var headers = dataGridView1.Columns.Cast<DataGridViewColumn>();
    sb.AppendLine(string.Join(";", headers.Select(column => "" + column.HeaderText + ";").ToArray()));

    foreach (DataGridViewRow row in dataGridView1.Rows)
    {
        var cells = row.Cells.Cast<DataGridViewCell>();
        sb.AppendLine(string.Join(";", cells.Select(cell => "" + cell.Value + ";").ToArray()));
    }

    try
    {
        File.WriteAllText(filename, sb.ToString());
    }
    catch (Exception exceptionObject)
    {
        MessageBox.Show(exceptionObject.ToString());
    }
}

The sb.ToString looks like this {Coumn;90;90;626;626;;}

The "real" StringBuilder Object as String is: {Coumn;\r\n90;\r\n90;\r\n626;\r\n626;\r\n;}

I want to remove the empty last row.

I tried to parse the stringbuilder to a string, and then remove last semicolon but with no success (i have problem with the End Of Line.)

string s = sb.ToString();
while (s.EndsWith(";\r\n;") == true)
{
    s.Substring(0, s.Length - 5);
}

I tried to remove last element of array, but StingBuilder is no array

I'm stuck.

If you only have 1 column, why bothering with `string.Join` for the cells? — dymanoid, Jan 11 '19 at 14:22
@dymanoid looks like a copy and paste of [this answer](https://stackoverflow.com/a/16295690/6144259) — A Friend, Jan 11 '19 at 14:25
Note that `Substring` does not _modify_ the string - try `s = s.Substring(0, s.Length - 5);` — D Stanley, Jan 11 '19 at 14:26
@dymanoid yes that's a point; could be more columns in the future @A Friend as stated in the question, Yes its derived from that answer — cuilster, Jan 11 '19 at 14:28
Wouldn't it be easier to just not add the empty line in the first place? — stuartd, Jan 11 '19 at 14:33

score 0 · Answer 1 · answered Jan 11 '19 at 15:35

As i found out the empty set is always exported to the csv. It's from the ability that the user can input data to the dataGridView, and there is always a empty, active row.

if i disable dataGridView1.AllowUserToAddRows the empty row for userinput is not within the stringbuilder set of data.

   void SaveDataGridViewToCSV(string filename)
    {
        var sb = new StringBuilder();

        //SOLUTION disable AllowUserInput to avoid empty set saved to CSV
        dataGridView1.AllowUserToAddRows = false;

        var headers = dataGridView1.Columns.Cast<DataGridViewColumn>();
        sb.AppendLine(string.Join(";", headers.Select(column => "" + column.HeaderText + ";").ToArray()));

        foreach (DataGridViewRow row in dataGridView1.Rows)
        {
            var cells = row.Cells.Cast<DataGridViewCell>();
            sb.AppendLine(string.Join(";", cells.Select(cell => "" + cell.Value + ";").ToArray()));
        }

        try
        {
            File.WriteAllText(filename, sb.ToString());
        }
        catch (Exception exceptionObject)
        {
            MessageBox.Show(exceptionObject.ToString());
        }
    }

thanks for help!

Remove last (empty) entry from StringBuilder object, when exporting to CSV

1 Answers1