ASP.Net: EshineASPNet教程-EXCEL導入與導出

完整教程鏈接：ASP.Net: EshineASPNet-基於ASP.Net敏捷開發開源框架

Excel的導入與導出是後臺最常用的功能之一了，這裏分享一下實現方式。

導入

要實現excel導入，這裏使用OLEDB，先引用System.Data.OleDb。

    public DataTable InputExcel(string TableName)
    {
        try
        {
            string strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + path  + ";" + "Extended Properties='Excel 8.0;HDR=YES;IMEX=1;'";
            OleDbConnection conn = new OleDbConnection(strConn);
            conn.Open();
            string strExcel = "select * from [" + TableName + "$]";
            OleDbDataAdapter myCommand = new OleDbDataAdapter(strExcel, strConn);
            DataTable dt = new DataTable();
            myCommand.Fill(dt);
            conn.Close();
            return dt;
        }
        catch (Exception ex)
        {
            return null;
        }
    }

上面的函數以Sheet名作爲輸入，支持中文，可以選擇Excel裏面的哪張表來導入，讀取的數據保存在DataTable。然後就可以對DataTable裏面的數據逐行處理並插入數據庫。

導出

如果數據是存在GridView控件裏面的，那麼有個簡便方法可以導出，先添加System.Web.UI和System.Web.UI.HtmlControls引用。

    public void gridviewtoexcel(GridView gv, string filename)
    {
        StringBuilder sb = new StringBuilder();
        StringWriter sw = new StringWriter(sb);
        HtmlTextWriter htw = new HtmlTextWriter(sw);

        Page page = new Page();
        HtmlForm form = new HtmlForm();

        for (int i = 0; i < gv.Rows.Count; i++)
        {
            if (gv.Rows[i].FindControl("GridView2") != null)
            {
                gv.Rows[i].Cells.RemoveAt(0);
                gv.Rows[i].Cells.RemoveAt(gv.Rows[i].Cells.Count - 1);
            }
        }

        gv.EnableViewState = false;

        // Deshabilitar la validación de eventos, sólo asp.net 2
        page.EnableEventValidation = false;

        // Realiza las inicializaciones de la instancia de la clase Page que requieran los diseñadores RAD.
        page.DesignerInitialize();

        page.Controls.Add(form);
        form.Controls.Add(gv);

        page.RenderControl(htw);

        System.Web.HttpContext.Current.Response.Clear();
        System.Web.HttpContext.Current.Response.AddHeader("content-disposition", "attachment;filename=" + filename + ".xls");
        System.Web.HttpContext.Current.Response.Charset = "UTF-8";
        System.Web.HttpContext.Current.Response.ContentEncoding = Encoding.Default;
        System.Web.HttpContext.Current.Response.ContentType = "application/excel";

        string style = @"<style> .text { mso-number-format:\@; } </script> ";
        System.Web.HttpContext.Current.Response.Write(style);

        System.Web.HttpContext.Current.Response.Write(sb.ToString());
        System.Web.HttpContext.Current.Response.End();
    }

上面是實現導出的標準代碼，其中Charset和style的設置用來支持中文和避免亂碼。
但如果是MVC的話這個就不太合適了，而且這種導出方式也有點問題，當遇到大且複雜的gridview時就知道了。那麼這時候就用下面的方法，在使用前需要引用NPOI.XSSF.UserModel，NPOI.SS.UserModel，NPOI.SS.Util。

    /// <summary>
    /// 根據dataTable生成Excel
    /// </summary>
    /// <param name="dt">數據源</param>
    /// <param name="sheetName">sheet名稱</param>
    /// <param name="header">標題</param>
    /// <returns></returns>
    public static XSSFWorkbook Export(DataTable dt, string sheetName, string header, out string msg)
    {
        try
        {
            XSSFWorkbook workbook = new XSSFWorkbook();
            ISheet sheet;
            if (!string.IsNullOrEmpty(sheetName))
                sheet = workbook.CreateSheet(sheetName);
            else
                sheet = workbook.CreateSheet("sheet1");

            ICellStyle dateStyle = workbook.CreateCellStyle();
            IDataFormat format = workbook.CreateDataFormat();
            dateStyle.DataFormat = format.GetFormat("yyyy-MM-dd hh:ss:mm");

            //取得列寬
            int[] arrColWidth = new int[dt.Columns.Count];
            foreach (DataColumn item in dt.Columns)
            {
                arrColWidth[item.Ordinal] = Encoding.GetEncoding(936).GetBytes(item.ColumnName.ToString()).Length;
            }

            for (int i = 0; i < dt.Rows.Count; i++)
            {
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    int intTemp = Encoding.GetEncoding(936).GetBytes(dt.Rows[i][j].ToString()).Length;
                    if (intTemp > arrColWidth[j])
                    {
                        arrColWidth[j] = intTemp;
                    }
                }
            }

            int rowIndex = 0;

            foreach (DataRow row in dt.Rows)
            {
                #region 新建表，填充表頭，填充列頭，樣式
                //if (rowIndex >= 1048570 || rowIndex == 0)
                if (rowIndex >= 1048570 || rowIndex == 0)
                {
                    if (rowIndex != 0)
                    {
                        sheet = workbook.CreateSheet();
                    }

                    #region 表頭及樣式
                    {
                        IRow headerRow = sheet.CreateRow(0);
                        headerRow.HeightInPoints = 25;
                        headerRow.CreateCell(0).SetCellValue(header);

                        ICellStyle headStyle = workbook.CreateCellStyle();
                        headStyle.Alignment = HorizontalAlignment.Center;
                        IFont font = workbook.CreateFont();
                        font.FontHeightInPoints = 20;
                        font.Boldweight = 700;
                        headStyle.SetFont(font);
                        headerRow.GetCell(0).CellStyle = headStyle;
                        sheet.AddMergedRegion(new CellRangeAddress(0, 0, 0, dt.Columns.Count - 1));
                        //headerRow
                    }
                    #endregion

                    #region 列頭及樣式
                    {
                        IRow headerRow = sheet.CreateRow(1);
                        ICellStyle headStyle = workbook.CreateCellStyle();
                        headStyle.Alignment = HorizontalAlignment.Center;
                        IFont font = workbook.CreateFont();
                        font.FontHeightInPoints = 10;
                        font.Boldweight = 700;
                        headStyle.SetFont(font);
                        foreach (DataColumn column in dt.Columns)
                        {
                            headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
                            headerRow.GetCell(column.Ordinal).CellStyle = headStyle;

                            //設置列寬
                            sheet.SetColumnWidth(column.Ordinal, (arrColWidth[column.Ordinal] + 1) * 256);
                        }
                        //headerRow.Dispose();
                    }
                    #endregion

                    rowIndex = 2;
                }
                #endregion

                #region 填充內容
                IRow dataRow = sheet.CreateRow(rowIndex);
                foreach (DataColumn column in dt.Columns)
                {
                    ICell newCell = dataRow.CreateCell(column.Ordinal);

                    string drValue = row[column].ToString();

                    switch (column.DataType.ToString())
                    {
                        case "System.String"://字符串類型
                            newCell.SetCellValue(drValue);
                            break;
                        case "System.DateTime"://日期類型
                            DateTime dateV;
                            bool torf = DateTime.TryParse(drValue, out dateV);
                            if (torf && dateV != System.Data.SqlTypes.SqlDateTime.MinValue && dateV != new DateTime())
                            {
                                newCell.SetCellValue(dateV);
                                newCell.CellStyle = dateStyle;//格式化顯示
                            }
                            else
                                newCell.SetCellValue("");
                            break;
                        case "System.Boolean"://布爾型
                            bool boolV = false;
                            bool.TryParse(drValue, out boolV);
                            newCell.SetCellValue(boolV);
                            break;
                        case "System.Int16"://整型
                        case "System.Int32":
                        case "System.Int64":
                        case "System.Byte":
                            int intV = 0;
                            int.TryParse(drValue, out intV);
                            newCell.SetCellValue(intV);
                            break;
                        case "System.Decimal"://浮點型
                        case "System.Double":
                            double doubV = 0;
                            double.TryParse(drValue, out doubV);
                            newCell.SetCellValue(doubV);
                            break;
                        case "System.DBNull"://空值處理
                            newCell.SetCellValue("");
                            break;
                        default:
                            newCell.SetCellValue("");
                            break;
                    }
                }
                #endregion

                rowIndex++;
            }
            msg = string.Empty;
            return workbook;
        }
        catch (Exception ex)
        {
            msg = ex.Message;
            return null;
        }
        //try
        //{
        //    FileStream fs = new FileStream(filename, FileMode.CreateNew);//(filename, FileMode.Create, FileAccess.Write);
        //    workbook.Write(fs);
        //    //fs.Flush();
        //    return true;
        //}
        //catch (Exception ex)
        //{
        //    throw new Exception(ex.Message);
        //    return false;
        //}
        //using (MemoryStream ms = new MemoryStream())
        //{
        //    workbook.Write(ms);
        //    ms.Flush();
        //    //ms.Position = 0;

        //    //sheet.Dispose();
        //    return ms;
        //}
    }


    public void DatatableToExcel(DataTable list)
    {
        string msg = string.Empty;
        XSSFWorkbook work = Export(list, "", "header", out msg);
        Response.Clear();
        Response.ClearHeaders();
        if (work == null && !string.IsNullOrEmpty(msg))
            throw new Exception(msg);
        Response.Buffer = false;
        Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";//ContentType;
        Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode("export.xlsx", System.Text.Encoding.UTF8));
        MemoryStream ms = new MemoryStream();
        work.Write(ms);
        Response.BinaryWrite(ms.ToArray());
        work = null;
        ms.Close();
        ms.Dispose();
        Response.Flush();
        Response.End();
    }

上面這種導出Excel方式同樣適用於MVC，可以實現DataTable到Excel的導出，並且網頁端直接彈出文件下載。如果要保存文件到本地可以參考註釋掉的那段代碼。

本教程代碼參考
EshineASPNet\Web\App_Code\upExcel.cs
EshineASPNet\Web\App_Code\PublicClass.cs

完整教程鏈接：ASP.Net: EshineASPNet-基於ASP.Net敏捷開發開源框架