• NPOI Excel Helper


     /// <summary>
        /// NPOIExcel帮助类
        /// </summary>
        public class NPOIExcelHelper
        {
            /// <summary>
            /// DataTable导出到Excel文件
            /// </summary>
            /// <param name="dtSource">源DataTable</param>
            /// <param name="strHeaderText">表头文本</param>
            /// <param name="strFileName">保存位置</param>
            public static void DataTableToExcel(DataTable dtSource, string strHeaderText, string strFileName)
            {
                ExcelFileSuffixType suffix = default(ExcelFileSuffixType);
                if (strFileName.IndexOf(".xlsx") > 0) // 2007版本
                    suffix = ExcelFileSuffixType.xlsx;
                else if (strFileName.IndexOf(".xls") > 0) // 2003版本
                    suffix = ExcelFileSuffixType.xls;
    
                using (MemoryStream ms = DataTableToExcelStream(dtSource, strHeaderText, suffix))
                {
                    using (FileStream fs = new FileStream(strFileName, FileMode.Create, FileAccess.Write))
                    {
                        byte[] data = ms.ToArray();
                        fs.Write(data, 0, data.Length);
                        fs.Flush();
                    }
                }
            }
    
            /// <summary>
            /// DataGridView导出到Excel文件
            /// </summary>
            /// <param name="dtSource">源DataTGridview</param>
            /// <param name="strHeaderText">表头文本</param>
            /// <param name="strFileName">保存位置</param>
            public static void DataGridViewToExcel(DataGridView myDgv, string strHeaderText, string strFileName)
            {
                ExcelFileSuffixType suffix = default(ExcelFileSuffixType);
                if (strFileName.IndexOf(".xlsx") > 0) // 2007版本
                    suffix = ExcelFileSuffixType.xlsx;
                else if (strFileName.IndexOf(".xls") > 0) // 2003版本
                    suffix = ExcelFileSuffixType.xls;
    
                using (MemoryStream ms = DataGridViewToExcelStream(myDgv, strHeaderText, suffix))
                {
                    using (FileStream fs = new FileStream(strFileName, FileMode.Create, FileAccess.Write))
                    {
                        byte[] data = ms.ToArray();
                        fs.Write(data, 0, data.Length);
                        fs.Flush();
                    }
                }
            }
    
            /// <summary>
            /// 将excel文件导入至DataTable
            /// </summary>
            /// <param name="strFileName">excel文件全路径</param>
            /// <returns></returns>
            public static DataTable ExcelToDataTable(string strFileName)
            {
                DataTable dt = new DataTable();
    
                IWorkbook workbook = null;
    
                using (FileStream file = new FileStream(strFileName, FileMode.Open, FileAccess.Read))
                {
    #if New_NPOI
                    if (strFileName.IndexOf(".xlsx") > 0) // 2007版本
                        workbook = new XSSFWorkbook(file);
                    else if (strFileName.IndexOf(".xls") > 0) // 2003版本
                        workbook = new HSSFWorkbook(file);
    #endif
    #if Old_NPOI
                    workbook = new HSSFWorkbook(file);
    #endif
                }
    
                ISheet sheet = workbook.GetSheetAt(0);
                System.Collections.IEnumerator rows = sheet.GetRowEnumerator();
    
                IRow headerRow = sheet.GetRow(0);
                int cellCount = headerRow.LastCellNum;
    
                for (int j = 0; j < cellCount; j++)
                {
                    ICell cell = headerRow.GetCell(j);
                    dt.Columns.Add(cell.ToString());
                }
    
                for (int i = (sheet.FirstRowNum + 1); i <= sheet.LastRowNum; i++)
                {
                    IRow row = sheet.GetRow(i);
                    DataRow dataRow = dt.NewRow();
    
                    for (int j = row.FirstCellNum; j < cellCount; j++)
                    {
                        if (row.GetCell(j) != null)
                            dataRow[j] = row.GetCell(j).ToString();
                    }
    
                    dt.Rows.Add(dataRow);
                }
    
                return dt;
            }
    
            #region private
            /// <summary>
            /// DataTable导出到Excel的MemoryStream
            /// </summary>
            /// <param name="dtSource">源DataTable</param>
            /// <param name="strHeaderText">表头文本</param>
            /// <param name="strHeaderText">excel文件后缀类型</param>
            private static MemoryStream DataTableToExcelStream(DataTable dtSource, string strHeaderText, ExcelFileSuffixType suffix)
            {
                ISheet sheet = null;
                IWorkbook workbook = null;
                ICellStyle cellStyle = null;
                IDataFormat dataFormat = null;
    
    #if New_NPOI
                if (suffix == ExcelFileSuffixType.xls)
                    workbook = new HSSFWorkbook();
                else if (suffix == ExcelFileSuffixType.xlsx)
                    workbook = new XSSFWorkbook();
    #endif
    #if Old_NPOI
                workbook = new HSSFWorkbook();
    #endif
    
                sheet = workbook.CreateSheet();
    
                cellStyle = workbook.CreateCellStyle();
                dataFormat = workbook.CreateDataFormat();
                cellStyle.DataFormat = dataFormat.GetFormat("yyyy-mm-dd");
    
                //取得列宽
                int[] arrColWidth = new int[dtSource.Columns.Count];
                foreach (DataColumn item in dtSource.Columns)
                {
                    arrColWidth[item.Ordinal] = Encoding.GetEncoding(936).GetBytes(item.ColumnName.ToString()).Length;
                }
                for (int i = 0; i < dtSource.Rows.Count; i++)
                {
                    for (int j = 0; j < dtSource.Columns.Count; j++)
                    {
                        int intTemp = Encoding.GetEncoding(936).GetBytes(dtSource.Rows[i][j].ToString()).Length;
                        if (intTemp > arrColWidth[j])
                        {
                            arrColWidth[j] = intTemp;
                        }
                    }
                }
                int rowIndex = 0;
                foreach (DataRow row in dtSource.Rows)
                {
                    #region 新建表,填充表头,填充列头,样式
                    if (rowIndex == 65535 || rowIndex == 0)
                    {
                        if (rowIndex != 0)
                        {
                            sheet = workbook.CreateSheet();
                        }
    
                        #region 表头及样式
                        {
                            IRow headerRow = sheet.CreateRow(0);
                            headerRow.HeightInPoints = 25;
                            headerRow.CreateCell(0).SetCellValue(strHeaderText);
    
                            ICellStyle headStyle = workbook.CreateCellStyle();
                            //headStyle.Alignment = CellHorizontalAlignment.CENTER;
                            IFont font = workbook.CreateFont();
                            font.FontHeightInPoints = 20;
    #if New_NPOI
                            font.IsBold = true;
    #endif
    #if Old_NPOI
                            font.Boldweight = 700;
    #endif
                            headStyle.SetFont(font);
                            headerRow.GetCell(0).CellStyle = headStyle;
                            //sheet.AddMergedRegion(new Region(0, 0, 0, dtSource.Columns.Count - 1));
                            //headerRow.Dispose();
                        }
                        #endregion
    
                        #region 列头及样式
                        {
                            IRow headerRow = sheet.CreateRow(1);
                            ICellStyle headStyle = workbook.CreateCellStyle();
                            //headStyle.Alignment = CellHorizontalAlignment.CENTER;
                            IFont font = workbook.CreateFont();
                            font.FontHeightInPoints = 10;
    #if New_NPOI
                            font.IsBold = true;
    #endif
    #if Old_NPOI
                            font.Boldweight = 700;
    #endif
                            headStyle.SetFont(font);
                            foreach (DataColumn column in dtSource.Columns)
                            {
                                headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
                                headerRow.GetCell(column.Ordinal).CellStyle = headStyle;
    
                                //设置列宽
                                //  sheet.SetColumnWidth(column.Ordinal, (arrColWidth[column.Ordinal] + 1) * 256); 
                            }
                            // headerRow.Dispose();
                        }
                        #endregion
    
                        rowIndex = 2;
                    }
                    #endregion
    
                    #region 填充内容
                    IRow dataRow = sheet.CreateRow(rowIndex);
                    foreach (DataColumn column in dtSource.Columns)
                    {
                        ICell newCell = dataRow.CreateCell(column.Ordinal);
    
                        string drValue = row[column].ToString();
    
                        switch (column.DataType.ToString())
                        {
                            case "System.String"://字符串类型
                                if (drValue.Length > 30000)
                                    drValue = drValue.Substring(0, 30000);
                                newCell.SetCellValue(drValue);
                                break;
                            case "System.DateTime"://日期类型
                                System.DateTime dateV;
                                System.DateTime.TryParse(drValue, out dateV);
                                newCell.SetCellValue(dateV);
    
                                newCell.CellStyle = cellStyle;//格式化显示
                                break;
                            case "System.Boolean"://布尔型
                                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"://浮点型
                            case "System.Double":
                                double doubV = 0;
                                double.TryParse(drValue, out doubV);
                                newCell.SetCellValue(doubV);
                                break;
                            case "System.DBNull"://空值处理
                                newCell.SetCellValue("");
                                break;
                            default:
                                newCell.SetCellValue("");
                                break;
                        }
    
                    }
                    #endregion
    
                    rowIndex++;
                }
    MemoryStream ms = new MemoryStream(); workbook.Write(ms); ms.Flush(); #if New_NPOI workbook.Close(); #endif return ms; } /// <summary> /// DataTable导出到Excel的MemoryStream /// </summary> /// <param name="myDgv">源DataTable</param> /// <param name="strHeaderText">表头文本</param> /// <param name="strHeaderText">excel文件后缀类型</param> private static MemoryStream DataGridViewToExcelStream(DataGridView myDgv, string strHeaderText, ExcelFileSuffixType suffix) { ISheet sheet = null; IWorkbook workbook = null; ICellStyle cellStyle = null; IDataFormat dataFormat = null; #if New_NPOI if (suffix == ExcelFileSuffixType.xls) workbook = new HSSFWorkbook(); else if (suffix == ExcelFileSuffixType.xlsx) workbook = new XSSFWorkbook(); #endif #if Old_NPOI workbook = new HSSFWorkbook(); #endif sheet = workbook.CreateSheet(); cellStyle = workbook.CreateCellStyle(); dataFormat = workbook.CreateDataFormat(); cellStyle.DataFormat = dataFormat.GetFormat("yyyy-mm-dd"); //取得列宽 int[] arrColWidth = new int[myDgv.Columns.Count]; foreach (DataGridViewColumn item in myDgv.Columns) { arrColWidth[item.Index] = Encoding.GetEncoding(936).GetBytes(item.HeaderText.ToString()).Length; } for (int i = 0; i < myDgv.Rows.Count; i++) { for (int j = 0; j < myDgv.Columns.Count; j++) { int intTemp = Encoding.GetEncoding(936).GetBytes(myDgv.Rows[i].Cells[j].ToString()).Length; if (intTemp > arrColWidth[j]) { arrColWidth[j] = intTemp; } } } int rowIndex = 0; foreach (DataGridViewRow row in myDgv.Rows) { #region 新建表,填充表头,填充列头,样式 if (rowIndex == 65535 || rowIndex == 0) { if (rowIndex != 0) { sheet = workbook.CreateSheet(); } #region 表头及样式 { IRow headerRow = sheet.CreateRow(0); headerRow.HeightInPoints = 25; headerRow.CreateCell(0).SetCellValue(strHeaderText); ICellStyle headStyle = workbook.CreateCellStyle(); //headStyle.Alignment = CellHorizontalAlignment.CENTER; IFont font = workbook.CreateFont(); font.FontHeightInPoints = 20; #if New_NPOI font.IsBold = true; #endif #if Old_NPOI font.Boldweight = 700; #endif headStyle.SetFont(font); headerRow.GetCell(0).CellStyle = headStyle; // sheet.AddMergedRegion(new Region(0, 0, 0, dtSource.Columns.Count - 1)); //headerRow.Dispose(); } #endregion #region 列头及样式 { IRow headerRow = sheet.CreateRow(1); ICellStyle headStyle = workbook.CreateCellStyle(); //headStyle.Alignment = CellHorizontalAlignment.CENTER; IFont font = workbook.CreateFont(); font.FontHeightInPoints = 10; #if New_NPOI font.IsBold = true; #endif #if Old_NPOI font.Boldweight = 700; #endif headStyle.SetFont(font); foreach (DataGridViewColumn column in myDgv.Columns) { headerRow.CreateCell(column.Index).SetCellValue(column.HeaderText); headerRow.GetCell(column.Index).CellStyle = headStyle; //设置列宽 //sheet.SetColumnWidth(column.Index, (arrColWidth[column.Index] + 1) * 256); } // headerRow.Dispose(); } #endregion rowIndex = 2; } #endregion #region 填充内容 IRow dataRow = sheet.CreateRow(rowIndex); if (row.Index > 0) { foreach (DataGridViewColumn column in myDgv.Columns) { ICell newCell = dataRow.CreateCell(column.Index); string drValue = myDgv[column.Index, row.Index - 1].Value.ToString(); switch (column.ValueType.ToString()) { case "System.String"://字符串类型 newCell.SetCellValue(drValue); break; case "System.DateTime"://日期类型 System.DateTime dateV; System.DateTime.TryParse(drValue, out dateV); newCell.SetCellValue(dateV); newCell.CellStyle = cellStyle;//格式化显示 break; case "System.Boolean"://布尔型 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"://浮点型 case "System.Double": double doubV = 0; double.TryParse(drValue, out doubV); newCell.SetCellValue(doubV); break; case "System.DBNull"://空值处理 newCell.SetCellValue(""); break; default: newCell.SetCellValue(""); break; } } } else { rowIndex--; } #endregion rowIndex++; }
    MemoryStream ms = new MemoryStream(); workbook.Write(ms); ms.Flush(); #if New_NPOI workbook.Close(); #endif return ms; } #endregion } /// <summary> /// excel文件后缀格式 /// </summary> enum ExcelFileSuffixType { /// <summary> /// Excel 2007及以上版本支持 /// </summary> xls, /// <summary> /// Excel 2003及以上版本兼容支持 /// </summary> xlsx }

    注,测试NPOI版本为:2.5.1.0,包含的文件及依赖:

     

    ------------恢复内容开始------------

     /// <summary>
        /// NPOIExcel帮助类
        /// </summary>
        public class NPOIExcelHelper
        {
            /// <summary>
            /// DataTable导出到Excel文件
            /// </summary>
            /// <param name="dtSource">源DataTable</param>
            /// <param name="strHeaderText">表头文本</param>
            /// <param name="strFileName">保存位置</param>
            public static void DataTableToExcel(DataTable dtSource, string strHeaderText, string strFileName)
            {
                ExcelFileSuffixType suffix = default(ExcelFileSuffixType);
                if (strFileName.IndexOf(".xlsx") > 0) // 2007版本
                    suffix = ExcelFileSuffixType.xlsx;
                else if (strFileName.IndexOf(".xls") > 0) // 2003版本
                    suffix = ExcelFileSuffixType.xls;
    
                using (MemoryStream ms = DataTableToExcelStream(dtSource, strHeaderText, suffix))
                {
                    using (FileStream fs = new FileStream(strFileName, FileMode.Create, FileAccess.Write))
                    {
                        byte[] data = ms.ToArray();
                        fs.Write(data, 0, data.Length);
                        fs.Flush();
                    }
                }
            }
    
            /// <summary>
            /// DataGridView导出到Excel文件
            /// </summary>
            /// <param name="dtSource">源DataTGridview</param>
            /// <param name="strHeaderText">表头文本</param>
            /// <param name="strFileName">保存位置</param>
            public static void DataGridViewToExcel(DataGridView myDgv, string strHeaderText, string strFileName)
            {
                ExcelFileSuffixType suffix = default(ExcelFileSuffixType);
                if (strFileName.IndexOf(".xlsx") > 0) // 2007版本
                    suffix = ExcelFileSuffixType.xlsx;
                else if (strFileName.IndexOf(".xls") > 0) // 2003版本
                    suffix = ExcelFileSuffixType.xls;
    
                using (MemoryStream ms = DataGridViewToExcelStream(myDgv, strHeaderText, suffix))
                {
                    using (FileStream fs = new FileStream(strFileName, FileMode.Create, FileAccess.Write))
                    {
                        byte[] data = ms.ToArray();
                        fs.Write(data, 0, data.Length);
                        fs.Flush();
                    }
                }
            }
    
            /// <summary>
            /// 将excel文件导入至DataTable
            /// </summary>
            /// <param name="strFileName">excel文件全路径</param>
            /// <returns></returns>
            public static DataTable ExcelToDataTable(string strFileName)
            {
                DataTable dt = new DataTable();
    
                IWorkbook workbook = null;
    
                using (FileStream file = new FileStream(strFileName, FileMode.Open, FileAccess.Read))
                {
    #if New_NPOI
                    if (strFileName.IndexOf(".xlsx") > 0) // 2007版本
                        workbook = new XSSFWorkbook(file);
                    else if (strFileName.IndexOf(".xls") > 0) // 2003版本
                        workbook = new HSSFWorkbook(file);
    #endif
    #if Old_NPOI
                    workbook = new HSSFWorkbook(file);
    #endif
                }
    
                ISheet sheet = workbook.GetSheetAt(0);
                System.Collections.IEnumerator rows = sheet.GetRowEnumerator();
    
                IRow headerRow = sheet.GetRow(0);
                int cellCount = headerRow.LastCellNum;
    
                for (int j = 0; j < cellCount; j++)
                {
                    ICell cell = headerRow.GetCell(j);
                    dt.Columns.Add(cell.ToString());
                }
    
                for (int i = (sheet.FirstRowNum + 1); i <= sheet.LastRowNum; i++)
                {
                    IRow row = sheet.GetRow(i);
                    DataRow dataRow = dt.NewRow();
    
                    for (int j = row.FirstCellNum; j < cellCount; j++)
                    {
                        if (row.GetCell(j) != null)
                            dataRow[j] = row.GetCell(j).ToString();
                    }
    
                    dt.Rows.Add(dataRow);
                }
    
                return dt;
            }
    
            #region private
            /// <summary>
            /// DataTable导出到Excel的MemoryStream
            /// </summary>
            /// <param name="dtSource">源DataTable</param>
            /// <param name="strHeaderText">表头文本</param>
            /// <param name="strHeaderText">excel文件后缀类型</param>
            private static MemoryStream DataTableToExcelStream(DataTable dtSource, string strHeaderText, ExcelFileSuffixType suffix)
            {
                ISheet sheet = null;
                IWorkbook workbook = null;
                ICellStyle cellStyle = null;
                IDataFormat dataFormat = null;
    
    #if New_NPOI
                if (suffix == ExcelFileSuffixType.xls)
                    workbook = new HSSFWorkbook();
                else if (suffix == ExcelFileSuffixType.xlsx)
                    workbook = new XSSFWorkbook();
    #endif
    #if Old_NPOI
                workbook = new HSSFWorkbook();
    #endif
    
                sheet = workbook.CreateSheet();
    
                cellStyle = workbook.CreateCellStyle();
                dataFormat = workbook.CreateDataFormat();
                cellStyle.DataFormat = dataFormat.GetFormat("yyyy-mm-dd");
    
                //取得列宽
                int[] arrColWidth = new int[dtSource.Columns.Count];
                foreach (DataColumn item in dtSource.Columns)
                {
                    arrColWidth[item.Ordinal] = Encoding.GetEncoding(936).GetBytes(item.ColumnName.ToString()).Length;
                }
                for (int i = 0; i < dtSource.Rows.Count; i++)
                {
                    for (int j = 0; j < dtSource.Columns.Count; j++)
                    {
                        int intTemp = Encoding.GetEncoding(936).GetBytes(dtSource.Rows[i][j].ToString()).Length;
                        if (intTemp > arrColWidth[j])
                        {
                            arrColWidth[j] = intTemp;
                        }
                    }
                }
                int rowIndex = 0;
                foreach (DataRow row in dtSource.Rows)
                {
                    #region 新建表,填充表头,填充列头,样式
                    if (rowIndex == 65535 || rowIndex == 0)
                    {
                        if (rowIndex != 0)
                        {
                            sheet = workbook.CreateSheet();
                        }
    
                        #region 表头及样式
                        {
                            IRow headerRow = sheet.CreateRow(0);
                            headerRow.HeightInPoints = 25;
                            headerRow.CreateCell(0).SetCellValue(strHeaderText);
    
                            ICellStyle headStyle = workbook.CreateCellStyle();
                            //headStyle.Alignment = CellHorizontalAlignment.CENTER;
                            IFont font = workbook.CreateFont();
                            font.FontHeightInPoints = 20;
    #if New_NPOI
                            font.IsBold = true;
    #endif
    #if Old_NPOI
                            font.Boldweight = 700;
    #endif
                            headStyle.SetFont(font);
                            headerRow.GetCell(0).CellStyle = headStyle;
                            //sheet.AddMergedRegion(new Region(0, 0, 0, dtSource.Columns.Count - 1));
                            //headerRow.Dispose();
                        }
                        #endregion
    
                        #region 列头及样式
                        {
                            IRow headerRow = sheet.CreateRow(1);
                            ICellStyle headStyle = workbook.CreateCellStyle();
                            //headStyle.Alignment = CellHorizontalAlignment.CENTER;
                            IFont font = workbook.CreateFont();
                            font.FontHeightInPoints = 10;
    #if New_NPOI
                            font.IsBold = true;
    #endif
    #if Old_NPOI
                            font.Boldweight = 700;
    #endif
                            headStyle.SetFont(font);
                            foreach (DataColumn column in dtSource.Columns)
                            {
                                headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
                                headerRow.GetCell(column.Ordinal).CellStyle = headStyle;
    
                                //设置列宽
                                //  sheet.SetColumnWidth(column.Ordinal, (arrColWidth[column.Ordinal] + 1) * 256); 
                            }
                            // headerRow.Dispose();
                        }
                        #endregion
    
                        rowIndex = 2;
                    }
                    #endregion
    
                    #region 填充内容
                    IRow dataRow = sheet.CreateRow(rowIndex);
                    foreach (DataColumn column in dtSource.Columns)
                    {
                        ICell newCell = dataRow.CreateCell(column.Ordinal);
    
                        string drValue = row[column].ToString();
    
                        switch (column.DataType.ToString())
                        {
                            case "System.String"://字符串类型
                                if (drValue.Length > 30000)
                                    drValue = drValue.Substring(0, 30000);
                                newCell.SetCellValue(drValue);
                                break;
                            case "System.DateTime"://日期类型
                                System.DateTime dateV;
                                System.DateTime.TryParse(drValue, out dateV);
                                newCell.SetCellValue(dateV);
    
                                newCell.CellStyle = cellStyle;//格式化显示
                                break;
                            case "System.Boolean"://布尔型
                                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"://浮点型
                            case "System.Double":
                                double doubV = 0;
                                double.TryParse(drValue, out doubV);
                                newCell.SetCellValue(doubV);
                                break;
                            case "System.DBNull"://空值处理
                                newCell.SetCellValue("");
                                break;
                            default:
                                newCell.SetCellValue("");
                                break;
                        }
    
                    }
                    #endregion
    
                    rowIndex++;
                }
                using (MemoryStream ms = new MemoryStream())
                {
                    workbook.Write(ms);
                    ms.Flush();
    #if New_NPOI
                    workbook.Close();
    #endif
                    return ms;
                }
            }
    
            /// <summary>
            /// DataTable导出到Excel的MemoryStream
            /// </summary>
            /// <param name="myDgv">源DataTable</param>
            /// <param name="strHeaderText">表头文本</param>
            /// <param name="strHeaderText">excel文件后缀类型</param>
            private static MemoryStream DataGridViewToExcelStream(DataGridView myDgv, string strHeaderText, ExcelFileSuffixType suffix)
            {
                ISheet sheet = null;
                IWorkbook workbook = null;
                ICellStyle cellStyle = null;
                IDataFormat dataFormat = null;
    
    #if New_NPOI
                if (suffix == ExcelFileSuffixType.xls)
                    workbook = new HSSFWorkbook();
                else if (suffix == ExcelFileSuffixType.xlsx)
                    workbook = new XSSFWorkbook();
    #endif
    #if Old_NPOI
                workbook = new HSSFWorkbook();
    #endif
                sheet = workbook.CreateSheet();
    
                cellStyle = workbook.CreateCellStyle();
                dataFormat = workbook.CreateDataFormat();
                cellStyle.DataFormat = dataFormat.GetFormat("yyyy-mm-dd");
    
                //取得列宽
                int[] arrColWidth = new int[myDgv.Columns.Count];
                foreach (DataGridViewColumn item in myDgv.Columns)
                {
                    arrColWidth[item.Index] = Encoding.GetEncoding(936).GetBytes(item.HeaderText.ToString()).Length;
                }
                for (int i = 0; i < myDgv.Rows.Count; i++)
                {
                    for (int j = 0; j < myDgv.Columns.Count; j++)
                    {
                        int intTemp = Encoding.GetEncoding(936).GetBytes(myDgv.Rows[i].Cells[j].ToString()).Length;
                        if (intTemp > arrColWidth[j])
                        {
                            arrColWidth[j] = intTemp;
                        }
                    }
                }
                int rowIndex = 0;
                foreach (DataGridViewRow row in myDgv.Rows)
                {
                    #region 新建表,填充表头,填充列头,样式
                    if (rowIndex == 65535 || rowIndex == 0)
                    {
                        if (rowIndex != 0)
                        {
                            sheet = workbook.CreateSheet();
                        }
    
                        #region 表头及样式
                        {
                            IRow headerRow = sheet.CreateRow(0);
                            headerRow.HeightInPoints = 25;
                            headerRow.CreateCell(0).SetCellValue(strHeaderText);
    
                            ICellStyle headStyle = workbook.CreateCellStyle();
                            //headStyle.Alignment = CellHorizontalAlignment.CENTER;
                            IFont font = workbook.CreateFont();
                            font.FontHeightInPoints = 20;
    #if New_NPOI
                            font.IsBold = true;
    #endif
    #if Old_NPOI
                            font.Boldweight = 700;
    #endif
                            headStyle.SetFont(font);
                            headerRow.GetCell(0).CellStyle = headStyle;
                            // sheet.AddMergedRegion(new Region(0, 0, 0, dtSource.Columns.Count - 1));
                            //headerRow.Dispose();
                        }
                        #endregion
    
    
                        #region 列头及样式
                        {
                            IRow headerRow = sheet.CreateRow(1);
                            ICellStyle headStyle = workbook.CreateCellStyle();
                            //headStyle.Alignment = CellHorizontalAlignment.CENTER;
                            IFont font = workbook.CreateFont();
                            font.FontHeightInPoints = 10;
    #if New_NPOI
                            font.IsBold = true;
    #endif
    #if Old_NPOI
                            font.Boldweight = 700;
    #endif
                            headStyle.SetFont(font);
                            foreach (DataGridViewColumn column in myDgv.Columns)
                            {
                                headerRow.CreateCell(column.Index).SetCellValue(column.HeaderText);
                                headerRow.GetCell(column.Index).CellStyle = headStyle;
    
                                //设置列宽
                                //sheet.SetColumnWidth(column.Index, (arrColWidth[column.Index] + 1) * 256);
                            }
                            // headerRow.Dispose();
                        }
                        #endregion
    
                        rowIndex = 2;
                    }
                    #endregion
    
                    #region 填充内容
                    IRow dataRow = sheet.CreateRow(rowIndex);
                    if (row.Index > 0)
                    {
                        foreach (DataGridViewColumn column in myDgv.Columns)
                        {
                            ICell newCell = dataRow.CreateCell(column.Index);
    
                            string drValue = myDgv[column.Index, row.Index - 1].Value.ToString();
    
                            switch (column.ValueType.ToString())
                            {
                                case "System.String"://字符串类型
                                    newCell.SetCellValue(drValue);
                                    break;
                                case "System.DateTime"://日期类型
                                    System.DateTime dateV;
                                    System.DateTime.TryParse(drValue, out dateV);
                                    newCell.SetCellValue(dateV);
    
                                    newCell.CellStyle = cellStyle;//格式化显示
                                    break;
                                case "System.Boolean"://布尔型
                                    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"://浮点型
                                case "System.Double":
                                    double doubV = 0;
                                    double.TryParse(drValue, out doubV);
                                    newCell.SetCellValue(doubV);
                                    break;
                                case "System.DBNull"://空值处理
                                    newCell.SetCellValue("");
                                    break;
                                default:
                                    newCell.SetCellValue("");
                                    break;
                            }
    
                        }
                    }
                    else
                    { rowIndex--; }
                    #endregion
    
                    rowIndex++;
                }
                using (MemoryStream ms = new MemoryStream())
                {
                    workbook.Write(ms);
                    ms.Flush();
    #if New_NPOI
                    workbook.Close();
    #endif
                    return ms;
                }
            }
            #endregion
        }
    
        /// <summary>
        /// excel文件后缀格式
        /// </summary>
        enum ExcelFileSuffixType
        {
            /// <summary>
            /// Excel 2007及以上版本支持
            /// </summary>
            xls,
            /// <summary>
            /// Excel 2003及以上版本兼容支持
            /// </summary>
            xlsx
        }

    注,测试NPOI版本为:2.5.1.0,包含的文件及依赖:

     

    ------------恢复内容结束------------

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  • 原文地址:https://www.cnblogs.com/seanyan/p/13813865.html
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