DataGridview 增加删除行

using System;
using System.Windows.Forms;

namespace DataGridViewSampCs
{
    public class FormHelper
    {
        #region 添加一行

        public void AddRow(DataGridView dg, string value)
        {
            if (dg.Rows.Count > 1)
            {
                DelRow(dg, dg.Rows.Count - 1);
            }
            dg.Rows.Add();
            for (int i = 0; i < dg.Columns.Count; i++)
            {
                dg.Rows[dg.Rows.Count - 1].Cells[i].Value = value;
            }
            dg.CurrentCell = dg.Rows[dg.Rows.Count - 1].Cells[0];
            TotalRow(dg);
        }

        #endregion 添加一行

        #region 编辑一行

        public void EditRow(DataGridView dg)
        {
            DelRow(dg, dg.Rows.Count - 1);
            TotalRow(dg);
        }

        #endregion 编辑一行

        #region 删除一行

        public void DelRow(DataGridView dg, int index)
        {
            dg.Rows.Remove(dg.Rows[index]);
        }

        #endregion 删除一行

        #region 合计行

        public void TotalRow(DataGridView dg)
        {
            dg.Rows.Add();
            DataGridViewRow dgr = dg.Rows[dg.Rows.Count - 1];
            dgr.ReadOnly = true;
            dgr.DefaultCellStyle.BackColor = System.Drawing.Color.Khaki;
            dgr.Cells[0].Value = "合计";
            for (int i = 0; i < dg.Rows.Count - 1; i++)
            {
                dgr.Cells[3].Value = Convert.ToSingle(dgr.Cells[3].Value) + Convert.ToSingle(dg.Rows[i].Cells[3].Value);
            }
        }

        #endregion 合计行
    }
}