C#导出数据到Excel的几种方法

首先说明，以下几种方法都是将DataTable 中导出数据到Excel 。

1、需要加载固定的Excel模板的方式

第一步，添加简单的 SaveFileDialog，以便将文件保存到合适的位置。

SaveFileDialog SaveDialog = new SaveFileDialog();
                    SaveDialog.Filter = "Excel 文件(*.xls)|*.xls|Excel 文件(*.xlsx)|*.xlsx|所有文件(*.*)|*.*";
                    SaveDialog.RestoreDirectory = true;
                    if (SaveDialog.ShowDialog() == DialogResult.OK)
                    {
                        GenerateAttachment(SaveDialog.FileName,dtExport);
                    }

第二步，真正的导出部分的代码

 try
            {
                //需要添加 Microsoft.Office.Interop.Excel引用 
                Microsoft.Office.Interop.Excel.Application app = new Microsoft.Office.Interop.Excel.Application();
                if (app == null)//服务器上缺少Excel组件，需要安装Office软件
                {
                    return;
                }
                app.Visible = false;
                app.UserControl = true;
                string strTempPath = System.Windows.Forms.Application.StartupPath + "\\Template\\Form.xls";
                Microsoft.Office.Interop.Excel.Workbooks workbooks = app.Workbooks;
                Microsoft.Office.Interop.Excel._Workbook workbook = workbooks.Add(strTempPath); //加载模板
                Microsoft.Office.Interop.Excel.Sheets sheets = workbook.Sheets;
                Microsoft.Office.Interop.Excel._Worksheet worksheet = (Microsoft.Office.Interop.Excel._Worksheet)sheets.get_Item(1); //第一个工作薄。
                if (worksheet == null)//工作薄中没有工作表
                {
                    return;
                }

                //1、获取数据
                int rowCount = DT.Rows.Count;
                if (rowCount < 1)//没有取到数据
                {
                    return;
                }
                //2、写入数据，Excel索引从1开始
                for (int i = 1; i <= rowCount; i++)
                {
                    int row_ = 1 + i;  //Excel模板上表头占了1行
                    int dt_row = i - 1; //dataTable的行是从0开始的 
                    worksheet.Cells[row_, 1] = DT.Rows[dt_row]["itemname"].ToString();
                    worksheet.Cells[row_, 2] = DT.Rows[dt_row]["Color"].ToString();
                    worksheet.Cells[row_, 3] = DT.Rows[dt_row]["Grade1"].ToString();
                   // worksheet.Cells[row_, 4] = DT.Rows[dt_row]["ProAreaName"].ToString();
                    worksheet.Cells[row_, 4] = DT.Rows[dt_row]["Quantity"].ToString();
                    worksheet.Cells[row_, 5] = DT.Rows[dt_row]["Unit_name"].ToString();
                    worksheet.Cells[row_, 6] = DT.Rows[dt_row]["TotalAmt"].ToString();
                    
                }
                worksheet.Cells[DT.Rows.Count + 2, 1] = "合计";
                worksheet.Cells[DT.Rows.Count + 2, 4] = DT.Compute("sum(Quantity)", "");
                worksheet.Cells[DT.Rows.Count + 2, 6] = DT.Compute("sum(TotalAmt)", "");
                //调整Excel的样式。
                //Microsoft.Office.Interop.Excel.Range rg = worksheet.Cells.get_Range("A3", worksheet.Cells[rowCount + 2, 32]);
                //rg.Borders.LineStyle = 1; //单元格加边框
                //worksheet.Columns.AutoFit(); //自动调整列宽

                //隐藏某一行
                //选中部分单元格，把选中的单元格所在的行的Hidden属性设为true
                //worksheet.get_Range(app.Cells[2, 1], app.Cells[2, 32]).EntireRow.Hidden = true;

                //删除某一行
               // worksheet.get_Range(app.Cells[2, 1], app.Cells[2, 32]).EntireRow.Delete(Microsoft.Office.Interop.Excel.XlDirection.xlUp);

                //3、保存生成的Excel文件
                //Missing在System.Reflection命名空间下
                //string savePath = System.Windows.Forms.Application.StartupPath+"/Temp/T1_" + DateTime.Now.ToString("yyyyMMddHHmmss") + ".xls";

                workbook.SaveAs(FileName, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlNoChange, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value);
                //workbook.SaveAs(FileName,FileFormat,Password,WriteResPassword,ReadOnlyRecommended,CreateBackup, AccessMode, ConflictResolution, AddToMru, TextCodepage, TextVisualLayout, Local) 
                //4、按顺序释放资源
                NAR(worksheet);
                NAR(sheets);
                NAR(workbook);
                NAR(workbooks);
                app.Quit();
                NAR(app);
                MessageBox.Show("保存成功", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            }
            catch (Exception ex)
            {
               MessageBox.Show("异常，异常信息为："+ex.ToString(),"");
            }

上述代码中  workbook.SaveAs()方法没有任何问题。开发过程中遇到错误为“值不在预期范围内”，报错位置在此方法，但出错的地方在上面的方法中，有可能是模板，有可能是FileName，总之，不会是这个方法。

第二种，调入内存导出

导入部分的方法

  public static void RenderDataTableToExcel(DataTable SourceTable, string FileName)
        {
            MemoryStream ms = RenderDataTableToExcel(SourceTable) as MemoryStream;
            FileStream fs = new FileStream(FileName, FileMode.Create, FileAccess.Write);
            byte[] data = ms.ToArray();

            fs.Write(data, 0, data.Length);
            fs.Flush();
            fs.Close();

            data = null;
            ms = null;
            fs = null;
        }

引用该方法的代码 ，其中strDataOutFile 同样可以用SaveFileDialog

 string strDataOutFile = TxtDataOutPath.Text.Trim() + TxtDataOutFileName.Text.Trim();
 RenderDataTableToExcel(DT_Item, strDataOutFile);

这种方法导出的数据全都是文本格式的，导出的Excel表格种的数据不能进行计算。暂时未找到合适的解决办法。
第三种，直接导出到临时表

 protected void ExportExcel(DataTable dt)
        {
            if (dt == null || dt.Rows.Count == 0) return;
            Microsoft.Office.Interop.Excel.Application xlApp = new Microsoft.Office.Interop.Excel.Application();

            if (xlApp == null)
            {
                return;
            }
            System.Globalization.CultureInfo CurrentCI = System.Threading.Thread.CurrentThread.CurrentCulture;
            System.Threading.Thread.CurrentThread.CurrentCulture = new System.Globalization.CultureInfo("en-US");
            Microsoft.Office.Interop.Excel.Workbooks workbooks = xlApp.Workbooks;
            Microsoft.Office.Interop.Excel.Workbook workbook = workbooks.Add(Microsoft.Office.Interop.Excel.XlWBATemplate.xlWBATWorksheet);
            Microsoft.Office.Interop.Excel.Worksheet worksheet = (Microsoft.Office.Interop.Excel.Worksheet)workbook.Worksheets[1];
            Microsoft.Office.Interop.Excel.Range range;
            long totalCount = dt.Rows.Count;
            long rowRead = 0;
            float percent = 0;
            for (int i = 1; i < dt.Columns.Count; i++)
            {
                worksheet.Cells[1, i] = dt.Columns[i].ColumnName;
                range = (Microsoft.Office.Interop.Excel.Range)worksheet.Cells[1, i];
                range.Interior.ColorIndex = 15;
                range.Font.Bold = true;
            }
            for (int r = 0; r < dt.Rows.Count; r++)
            {
                for (int i = 1; i < dt.Columns.Count; i++)
                {
                    worksheet.Cells[r + 2, i] = dt.Rows[r][i].ToString();
                }
                rowRead++;
                percent = ((float)(100 * rowRead)) / totalCount;
            }
            worksheet.Cells[dt.Rows.Count + 2, 1] = "合计";
            worksheet.Cells[dt.Rows.Count + 2, 5] = textBox2.Text;
            xlApp.Visible = true;
        }