Hide DataGridView columns with no data in any row

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web;
using System.Web.UI.WebControls;

namespace Dashboard_Test
{
    public static class ExtensionGridView
    {
        public static GridView RemoveEmptyColumns(this GridView gv)
        {
            // Make sure there are at least header row
            if (gv.HeaderRow != null)
            {
                int columnIndex = 0;

                // For each column
                foreach (DataControlFieldCell clm in gv.HeaderRow.Cells)
                {
                    bool notAvailable = true;

                    // For each row
                    foreach (GridViewRow row in gv.Rows)
                    {
                        string columnData = row.Cells[columnIndex].Text;
                        if (!(string.IsNullOrEmpty(columnData) || columnData ==" "))
                        {
                            notAvailable = false;
                            break;
                        }
                    }

                    if (notAvailable)
                    {
                        // Hide the target header cell
                        gv.HeaderRow.Cells[columnIndex].Visible = false;

                        // Hide the target cell of each row
                        foreach (GridViewRow row in gv.Rows)
                            row.Cells[columnIndex].Visible = false;
                    }

                    columnIndex++;
                }
            }

            return gv;
        }
    }
}

public static DataGridView RemoveEmptyColumns(this DataGridView grdView) {
    foreach (DataGridViewColumn clm in grdView.Columns) {
        bool notAvailable = true;
        //// If you don't want to hide button columns
        //if (clm is DataGridViewButtonColumn)
        //    continue;
        foreach (DataGridViewRow row in grdView.Rows) {
            if(row.Cells[clm.Index].Value == null)
                notAvailable = true;
           else if (!string.IsNullOrEmpty(row.Cells[clm.Index].Value.ToString())){
                notAvailable = false;
                break;
            }
        }
        if (notAvailable) {
            grdView.Columns[clm.Index].Visible = false;
        }
    }
    return grdView;
}