DataColumn Name from DataRow (not DataTable)

I need to iterate the columnname and column datatype from a specific row. All of the examples I have seen have iterated an entire datatable. I want to pass a single row to a function to do a bunch of conditional processing. I want to separate the conditional processing for ease of readability.

This is what I have:

private void doMore(DataRow dr)
{
    foreach (DataColumn c in dr.ItemArray)  //loop through the columns. 
    {
        MessageBox.Show(c.ColumnName.ToString());
    }
}

The error returned is

>System.InvalidCastException: Unable to cast object of type 'System.String' to type 'System.Data.DataColumn'.

How would I get the column name from the row or do I have no choice and must pass the entire datatable to the function?

You would still need to go through the DataTable class. But you can do so using your DataRow instance by using the Table property.

foreach (DataColumn c in dr.Table.Columns)  //loop through the columns. 
{
    MessageBox.Show(c.ColumnName);
}

You can make it easier in your code (if you're doing this a lot anyway) by using an extension on the DataRow object, like:

static class Extensions
{
    public static string GetColumn(this DataRow Row, int Ordinal)
    {
        return Row.Table.Columns[Ordinal].ColumnName;
    }
}

Then call it using:

string MyColumnName = MyRow.GetColumn(5);

You need something like this:

foreach(DataColumn c in dr.Table.Columns)
{
  MessageBox.Show(c.ColumnName);
}

use DataTable object instead:

 private void doMore(DataTable dt)
    {
    foreach(DataColumn dc in dt.Columns)
    {
    MessageBox.Show(dc.ColumnName);
    }
    }