IndexOutOfRange Exception when working with DataTable

Question

I'm using StreamReader to access to CSV text file and read all the lines to a DataTable.

public static DataTable ConvertToDataTable(string filePath, int numberOfColumns)
    {
        DataTable tbl = new DataTable();

        for (int col = 0; col < numberOfColumns; col++)
            tbl.Columns.Add(new DataColumn("Column" + (col + 1).ToString()));

        string line;
        System.IO.StreamReader file = new StreamReader("C:/ProgramData/3CX/Instance1/Data/Logs/CDRLogs/cdr.log");

        while ((line = file.ReadLine()) != null)
        {
            var cols = line.Split(',');
            DataRow dr = tbl.NewRow();
            for (int cIndex = 0; cIndex < cols.Length + 1; cIndex++)
            {
                dr[cIndex] = cols[cIndex];
            }
            tbl.Rows.Add(dr);
        }

Once I've added all the CSV rows to the DataTable I want to iterate through the rows and remomve unwanted rows on conditions.

DataTable dt = ConvertToDataTable("C:/ProgramData/3CX/Instance1/Data/Logs/CDRLogs", 4);

        for (int i = 0; i < dt.Rows.Count; i++)
        {
            string duration = dt.Rows[i][1].ToString();
            if (duration == "")
            {
                dt.Rows[i].Delete();
            }
            Console.WriteLine(i.ToString() + dt.Rows[i][1].ToString());
        }

This runs just fine until I reach the last row, where it seems to be looping through a row that doesn't exist.

Anyone have an idea as to why? Any and all help would be greatly appreciated!

Answer 1

You can iterate trough the rows backwards to keep the indices as they are.

for(int i = dt.Rows.Count - 1; i >= 0; i--)
{
   dt.Rows[i].Delete();
}