c# excel转换为DataTable

 System.Data.DataTable GetDataFromExcelByCom(bool hasTitle, string fileName)
        {
            //OpenFileDialog openFile = new OpenFileDialog();
            //openFile.Filter = "Excel(*.xlsx)|*.xlsx|Excel(*.xls)|*.xls";
            //openFile.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);
            //openFile.Multiselect = false;
            //if (openFile.ShowDialog() == DialogResult.Cancel) return null;
            //var excelFilePath = openFile.FileName;

            Microsoft.Office.Interop.Excel.Application app = new Microsoft.Office.Interop.Excel.Application();
            Sheets sheets;
            object oMissiong = System.Reflection.Missing.Value;
            Workbook workbook = null;
            System.Data.DataTable dt = new System.Data.DataTable();

            try
            {
                if (app == null) return null;
                workbook = app.Workbooks.Open(fileName, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong,
                    oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong);
                sheets = workbook.Worksheets;

                //将数据读入到DataTable中
                Worksheet worksheet = (Worksheet)sheets.get_Item(1);//读取第一张表  
                if (worksheet == null) return null;

                int iRowCount = worksheet.UsedRange.Rows.Count;
                int iColCount = worksheet.UsedRange.Columns.Count;
                //生成列头
                for (int i = 0; i < iColCount; i++)
                {
                    var name = "column" + i;
                    if (hasTitle)
                    {
                        var txt = ((Range)worksheet.Cells[1, i + 1]).Text.ToString();
                        if (!string.IsNullOrEmpty(txt)) name = txt;
                    }
                    while (dt.Columns.Contains(name)) name = name + "_1";//重复行名称会报错。
                    dt.Columns.Add(new DataColumn(name, typeof(string)));
                }
                //生成行数据
                Range range;
                int rowIdx = hasTitle ? 2 : 1;
                for (int iRow = rowIdx; iRow <= iRowCount; iRow++)
                {
                    DataRow dr = dt.NewRow();
                    for (int iCol = 1; iCol <= iColCount; iCol++)
                    {
                        range = (Range)worksheet.Cells[iRow, iCol];
                        dr[iCol - 1] = (range.Value2 == null) ? "" : range.Text.ToString();
                    }
                    dt.Rows.Add(dr);
                }



                return dt;
            }
            catch { return null; }
            finally
            {
                workbook.Close(false, oMissiong, oMissiong);
                System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook);
                workbook = null;
                app.Workbooks.Close();
                app.Quit();
                System.Runtime.InteropServices.Marshal.ReleaseComObject(app);
                app = null;
            }
        }