using (OpenFileDialog fd = new OpenFileDialog()){    fd.Filter = "Excel 2007文件(*.xlsx)|*.xlsx|所有文件(*.*)|*.*";    if (fd.ShowDialog(this) == System.Windows.Forms.DialogResult.OK)    {        try        {            using (ExcelPackage pack = new ExcelPackage(new FileInfo(fd.FileName)))            {                ExcelWorksheet sheet = pack.Workbook.Worksheets[1];                var rowCount = sheet.Dimension.End.Row;                var columnCount = sheet.Dimension.End.Column;                DataTable dt = new DataTable();                for (int j = 1; j <= columnCount; j++)                {                    dt.Columns.Add("A" + j.ToString());                }                for (int i = 1; i <= rowCount; i++)                {                    dt.Rows.Add(dt.NewRow());                    for (int j = 1; j <= columnCount; j++)                    {                        dt.Rows[i - 1][j - 1] = sheet.Cells[i, j].Value;                    }                }                dataGridView1.DataSource = dt;            }        }        catch (Exception ex)        {            MessageBox.Show(this, ex.Message, "错误", MessageBoxButtons.OK, MessageBoxIcon.Warning);        }    }}

需要注意的是，Epplus 开源免费，但只支持 Excel 2007 或更高版本