总结 | C#实现Excel导出功能

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一、效果展示

在最近开发任务中使用到了第三方类库NPOI，简单总结一下自己使用的心得体会。如果存在漏洞或不足请多多指正。

1.实现功能

• 表格数据的写入
• 下拉框
• 图片插入

2.效果展示

• 表格数据写入 与 图片插入
  
• 下拉框
  

二、代码实现

1.引入库

2.读入数据

代码如下（示例）：

		/// 

        /// 导出Excel样例
        /// 
        /// 
        public string GetExportExcelExamples()
        {
            string result = "导出失败";

            try
            {
                int CurrRow = 0;//当前Excel写入的行数

                #region 1、创建Excel格式，并写入数据

                HSSFWorkbook workbook = new HSSFWorkbook();//初始化一个新的HSSFWorkbook实例
                ISheet sheet = workbook.CreateSheet("销售财务统计表");//创建一个sheet表
                //设置列宽
                for (int i = 0; i < 13; i++)
                {
                    sheet.SetColumnWidth(i, 20 * 130);
                }
                sheet.SetColumnWidth(0, 20 * 150);
                //设置单元格样式类型（单元格样式【单元格图案、填充模式、单元格背景色、边框、是否自动换行】、字体样式【字体类型、字体大小、字体颜色、字体是否加粗】）
                //(1)大标题格式
                ICellStyleVo cellStyleVo = new ICellStyleVo(HSSFColor.Grey50Percent.Index, FillPattern.SolidForeground, HSSFColor.Grey50Percent.Index, BorderStyle.Thin, true);
                FontStyleVo fontStyleVo = new FontStyleVo("华文行楷", 18 * 18, HSSFColor.White.Index, false);
                ICellStyle bigHeadStyle = SetICellStyle(workbook, cellStyleVo, fontStyleVo);
                //(2)表格标题格式
                cellStyleVo = new ICellStyleVo(HSSFColor.Grey50Percent.Index, FillPattern.SolidForeground, HSSFColor.Grey50Percent.Index, BorderStyle.Thin, true);
                fontStyleVo = new FontStyleVo("华文行楷", 15 * 15, HSSFColor.White.Index, false);
                ICellStyle tableHeadStyle = SetICellStyle(workbook, cellStyleVo, fontStyleVo);
                //(3)表格正文格式（加粗）
                cellStyleVo = new ICellStyleVo(HSSFColor.Grey40Percent.Index, FillPattern.SolidForeground, HSSFColor.Grey40Percent.Index, BorderStyle.Thin, true);
                fontStyleVo = new FontStyleVo("华文行楷", 15 * 15, HSSFColor.Black.Index, true);
                ICellStyle tableTextBoldStyle = SetICellStyle(workbook, cellStyleVo, fontStyleVo);
                //(4)表格正文格式（不加粗）
                cellStyleVo = new ICellStyleVo(HSSFColor.Grey25Percent.Index, FillPattern.SolidForeground, HSSFColor.Grey25Percent.Index, BorderStyle.Thin, true);
                fontStyleVo = new FontStyleVo("华文行楷", 15 * 15, HSSFColor.Black.Index, false);
                ICellStyle tableTextStyle = SetICellStyle(workbook, cellStyleVo, fontStyleVo);

                #region 1.1、写入头部信息

                sheet.AddMergedRegion(new CellRangeAddress(CurrRow, CurrRow, 0, 12));//合并单元格
                IRow rowH = sheet.CreateRow(CurrRow);//创建一行
                ICell cell = rowH.CreateCell(0);//创建一列
                cell.SetCellValue("年终销售业绩财务数据统计表—动态分析");
                cell.CellStyle = bigHeadStyle;//设置单元格样式

                CurrRow += 2;

                #endregion

                #region 1.2、写入表格信息

                //表格头部
                rowH = sheet.CreateRow(CurrRow);
                for (int i = 0; i < 13; i++)
                {
                    cell = rowH.CreateCell(i);
                    if (i > 0)
                        cell.SetCellValue(i + "月");
                    cell.CellStyle = tableHeadStyle;
                }
                CurrRow += 1;
                //表格Body
                int[,] saleData = new int[,] 
                {
                    { 5,28,50,69,58,122,134,158,28,93,94,183},
                    { 150,125,24,82,58,114,81,85,124,25,94,72},
                    { 138,123,68,85,5,12,34,58,128,83,114,83},
                    { 18,4,50,69,58,22,34,118,128,43,88,133},
                    { 8,65,150,169,158,22,34,134,128,113,35,138},
                    { 132,128,30,79,88,122,184,58,128,56,63,156},
                    { 10,28,150,169,58,142,43,78,28,73,124,153}
                };//销售数据
                for (int i = 0; i < saleData.GetLength(0); i++)//数组行数
                {
                    rowH = sheet.CreateRow(CurrRow);
                    cell = rowH.CreateCell(0);
                    cell.SetCellValue("销售"+ (i + 1) +"部");
                    cell.CellStyle = tableTextStyle;

                    for (int j = 0; j < saleData.GetLength(1); j++)//数组列数
                    {
                        cell = rowH.CreateCell(j + 1);
                        cell.SetCellValue(saleData[i, j]);
                        cell.CellStyle = tableTextStyle;
                    }

                    CurrRow += 1;
                }



                #endregion

                #region 1.3、插入图片

                //下拉菜单
                rowH = sheet.CreateRow(CurrRow);
                cell = rowH.CreateCell(11);
                cell.SetCellValue("下拉框");
                cell.CellStyle = tableHeadStyle;
                cell = rowH.CreateCell(12);
                cell.SetCellValue("请选择");
                cell.CellStyle = tableHeadStyle;
                CellRangeAddressList cellRangeAddressList = new CellRangeAddressList(CurrRow, CurrRow, 12, 12);
                DVConstraint dVConstraint = DVConstraint.CreateExplicitListConstraint(new string[] { "销售1部", "销售2部", "销售3部", "销售4部", "销售5部", "销售6部", "销售7部" });
                HSSFDataValidation dataValidate = new HSSFDataValidation(cellRangeAddressList, dVConstraint);
                sheet.AddValidationData(dataValidate);

                CurrRow += 1;

                //簇状柱状图
                string picPath = "C:/Users/Administrator/Desktop/Export/柱状图.png";
                byte[] bytes = System.IO.File.ReadAllBytes(picPath);
                int pictureIdx = workbook.AddPicture(bytes, PictureType.PNG);
                HSSFPatriarch patriarch = (HSSFPatriarch)sheet.CreateDrawingPatriarch();//在sheet中创建画布
                HSSFClientAnchor anchor = new HSSFClientAnchor(0, 0, 0, 0, 0, 11, 13, 38);//设置锚点（在起始单元格的X坐标0-1023，Y的坐标0-255，在终止单元格的X坐标0-1023，Y的坐标0-255，起始单元格列数，行数，终止单元格列数，行数）
                HSSFPicture pict = (HSSFPicture)patriarch.CreatePicture(anchor, pictureIdx);//把图片插到相应的位置
                pict.Resize();//自动调节图片大小，防止图片被拉伸变形

                #endregion

                #endregion

                #region 2、文件导出

                string path = "C:/Users/Administrator/Desktop/Export/Example1.xls";
                if (System.IO.File.Exists(path))
                {
                    File.Delete(Path.GetFullPath(path));
                }
                FileStream file = new FileStream(path, FileMode.Create);
                workbook.Write(file);
                file.Close();

                #endregion

                result = "导出成功";
            }
            catch (Exception ex)
            {
                object msg = string.Concat("ExportExcels(GetExportExcelExamples)——导出Excel样例");
                Log4NetHelper.ErrorLog(msg, ex);
            }

            return result;
        }

3.设置单元格样式

		/// 

        /// 设置单元格样式
        /// 
        /// Excel工作单元
        /// 单元格图案
        /// 填充模式
        /// 单元格背景色
        /// 边框
        /// 是否自动换行
        /// 字体类型
        /// 字体大小
        /// 字体颜色
        /// 字体是否加粗
        /// 
        public ICellStyle SetICellStyle(HSSFWorkbook workbook, ICellStyleVo cellStyleVo, FontStyleVo fontStyleVo)
        {
            ICellStyle cellStyle = workbook.CreateCellStyle();
            
            #region [+]设置通用样式

            #region [+]1、单元格通用样式

            cellStyle.VerticalAlignment = VerticalAlignment.Center;//垂直居中
            cellStyle.Alignment = HorizontalAlignment.Center;//水平居中
            //设置单元格的背景和图案（注意坑：顺序）
            cellStyle.FillBackgroundColor = cellStyleVo.FillBackgroundColor;//背景
            cellStyle.FillPattern = cellStyleVo.FillPattern;//填充模式（必须设置）
            cellStyle.FillForegroundColor = cellStyleVo.FillForegroundColor;//图案
            //设置边框
            //cellStyle.BorderTop = cellStyleVo.BorderStyle;
            //cellStyle.BorderBottom = cellStyleVo.BorderStyle;
            //cellStyle.BorderLeft = cellStyleVo.BorderStyle;
            //cellStyle.BorderRight = cellStyleVo.BorderStyle;
            //自动换行
            cellStyle.WrapText = cellStyleVo.IsWrapText;

            #endregion

            #region [+]2、字体通用样式

            IFont font = workbook.CreateFont();
            font.FontName = fontStyleVo.FontName;//字体类型
            font.FontHeight = fontStyleVo.FontHeight;//字体大小
            font.Color = fontStyleVo.fontColor;//字体颜色
            font.IsBold = fontStyleVo.IsBold;//字体是否加粗
            cellStyle.SetFont(font);//把字体应用到当前样式

            #endregion

            return cellStyle;

            #endregion
        }

4.自定义类

	/// 

    /// 单元格样式模型
    /// 
    public class ICellStyleVo
    {
        /// 

        /// 单元格图案
        /// 
        public short FillForegroundColor { get; set; } = HSSFColor.White.Index;
        /// 

        /// 填充模式
        /// 
        public FillPattern FillPattern { get; set; } = FillPattern.SolidForeground;
        /// 

        /// 单元格背景色
        /// 
        public short FillBackgroundColor { get; set; } = HSSFColor.White.Index;
        /// 

        /// 边框
        /// 
        public BorderStyle BorderStyle { get; set; } = BorderStyle.None;
        /// 

        /// 是否自动换行
        /// 
        public bool IsWrapText { get; set; } = false;

        public ICellStyleVo(short FillForegroundColor = HSSFColor.White.Index, FillPattern FillPattern = FillPattern.SolidForeground, short FillBackgroundColor = HSSFColor.White.Index, BorderStyle BorderStyle = BorderStyle.Thin, bool IsWrapText = false)
        {
            this.FillForegroundColor = FillForegroundColor;
            this.FillPattern = FillPattern;
            this.FillBackgroundColor = FillBackgroundColor;
            this.BorderStyle = BorderStyle;
            this.IsWrapText = IsWrapText;
        }

    }

    /// 

    /// 字体样式模型
    /// 
    public class FontStyleVo
    {
        /// 

        /// 字体类型
        /// 
        public string FontName { get; set; } = "宋体";
        /// 

        /// 字体大小
        /// 
        public double FontHeight { get; set; } = 15 * 15;
        /// 

        /// 字体颜色
        /// 
        public short fontColor { get; set; } = HSSFColor.Black.Index;
        /// 

        /// 字体是否加粗
        /// 
        public bool IsBold { get; set; } = false;

        public FontStyleVo(string FontName = "宋体", double FontHeight = 15 * 15, short fontColor = HSSFColor.Black.Index, bool IsBold = false)
        {
            this.FontName = FontName;
            this.FontHeight = FontHeight;
            this.fontColor = fontColor;
            this.IsBold = IsBold;
        }
    }

三、遇到的坑

• 竖向合并单元格时，必须在第一行写入数据，否则无法写入数据；

例如：合并第一列中的第1~3行

//正确使用方法
int CurrRow = 0;
IRow rowTemp = sheet.CreateRow(CurrRow);
sheet.AddMergedRegion(new CellRangeAddress(CurrRow, CurrRow + 3, 0, 0));
cell = rowTemp.CreateCell(0);
cell.SetCellValue("学习");
//错误使用方法
int CurrRow = 3;
IRow rowTemp = sheet.CreateRow(CurrRow);
sheet.AddMergedRegion(new CellRangeAddress(CurrRow - 3, CurrRow, 0, 0));
cell = rowTemp.CreateCell(0);
cell.SetCellValue("学习");

四、参考文档

• NPOI使用手册：https://www.cnblogs.com/joean/p/4661056.html
• FillPattern填充模式效果：https://blog.csdn.net/qq_39541254/article/details/107940224
• HSSFColor中Excel表格颜色对照表：https://blog.csdn.net/qq_27937043/article/details/72779442
• 自定义色调：https://blog.csdn.net/pyc_01/article/details/100599632

总结

目前NPOI对基础的表格导出的API比较完善，但对于高级Chart图的开发接口比较匮乏。