NPOI在DataGridView中展示excel中的数据

        HSSFWorkbook hssfworkbook;
        DataSet ds = new DataSet();
/// <summary>
/// 初始化一个工作薄
/// </summary>
/// <param name="path">工作薄的路径</param>
void InitializeWorkbook(string path)
        {
using (FileStream file = new FileStream(path, FileMode.Open, FileAccess.Read))
            {
                hssfworkbook = new HSSFWorkbook(file);
            }
        }
void ConvertToDataTable()
        {
            ISheet sheet = hssfworkbook.GetSheetAt(0);
            System.Collections.IEnumerator rows = sheet.GetRowEnumerator();

            DataTable dt = new DataTable();
for (int i = 0; i < sheet.GetRow(0).LastCellNum; i++)
            {
                dt.Columns.Add(Convert.ToChar(((int)'A') + i).ToString());
            }
while (rows.MoveNext())
            {
                IRow row = (HSSFRow)rows.Current;
                DataRow dr = dt.NewRow();
for (int j = 0; j < row.LastCellNum; j++)
                {
                    ICell cell = row.GetCell(j);
if (cell == null)
                    {
                        dr[j] = null;
                    }
else
                    {
                        dr[j] = cell;
                    }
                }
                dt.Rows.Add(dr);
            }
            ds.Tables.Add(dt);
        }
private void btnReader_Click(object sender, EventArgs e)
        {
            InitializeWorkbook("test.xls");
            ConvertToDataTable();
            dgViewTest.DataSource = ds.Tables[0];
        }

附：
使用NPOI将DataGridView的数据导出EXCEL