NPOI DataGridView导出Excel

using NPOI.HSSF.UserModel; using NPOI.SS.UserModel;

#region NPOI DataGridView 导出 EXCEL        /// <summary>        /// NPOI DataGridView 导出 EXCEL        /// </summary>        /// <param name="fileName"> 默认保存文件名</param>        /// <param name="dgv">DataGridView</param>        /// <param name="fontname">字体名称</param>        /// <param name="fontsize">字体大小</param>        public void ExportExcel(string fileName, DataGridView dgv, string fontname, short fontsize)        {            //检测是否有数据            if (dgv.SelectedRows.Count == 0) return;            //创建主要对象            HSSFWorkbook workbook = new HSSFWorkbook();            HSSFSheet sheet = (HSSFSheet)workbook.CreateSheet("Weight");            //设置字体，大小，对齐方式            HSSFCellStyle style = (HSSFCellStyle)workbook.CreateCellStyle();            HSSFFont font = (HSSFFont)workbook.CreateFont();            font.FontName = fontname;            font.FontHeightInPoints = fontsize;            style.SetFont(font);            style.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center; //居中对齐            //添加表头            HSSFRow dataRow = (HSSFRow)sheet.CreateRow(0);            for (int i = 0; i < dgv.Columns.Count; i++)            {                dataRow.CreateCell(i).SetCellValue(dgv.Columns[i].HeaderText);                dataRow.GetCell(i).CellStyle = style;            }            //注释的这行是设置筛选的            //sheet.SetAutoFilter(new CellRangeAddress(0, dgv.Columns.Count, 0, dgv.Columns.Count));            //添加列及内容            for (int i = 0; i < dgv.Rows.Count; i++)            {                dataRow = (HSSFRow)sheet.CreateRow(i + 1);                for (int j = 0; j < dgv.Columns.Count; j++)                {                    string ValueType = dgv.Rows[i].Cells[j].Value.GetType().ToString();                    string Value = dgv.Rows[i].Cells[j].Value.ToString();                    switch (ValueType)                    {                        case "System.String"://字符串类型                            dataRow.CreateCell(j).SetCellValue(Value);                            break;                        case "System.DateTime"://日期类型                            System.DateTime dateV;                            System.DateTime.TryParse(Value, out dateV);                            dataRow.CreateCell(j).SetCellValue(dateV);                            break;                        case "System.Boolean"://布尔型                            bool boolV = false;                            bool.TryParse(Value, out boolV);                            dataRow.CreateCell(j).SetCellValue(boolV);                            break;                        case "System.Int16"://整型                        case "System.Int32":                        case "System.Int64":                        case "System.Byte":                            int intV = 0;                            int.TryParse(Value, out intV);                            dataRow.CreateCell(j).SetCellValue(intV);                            break;                        case "System.Decimal"://浮点型                        case "System.Double":                            double doubV = 0;                            double.TryParse(Value, out doubV);                            dataRow.CreateCell(j).SetCellValue(doubV);                            break;                        case "System.DBNull"://空值处理                            dataRow.CreateCell(j).SetCellValue("");                            break;                        default:                            dataRow.CreateCell(j).SetCellValue("");                            break;                    }                    dataRow.GetCell(j).CellStyle = style;                    //设置宽度                    sheet.SetColumnWidth(j, (Value.Length + 10) * 256);                }            }            //保存文件            string saveFileName = "";            SaveFileDialog saveDialog = new SaveFileDialog();            saveDialog.DefaultExt = "xls";            saveDialog.Filter = "Excel文件|*.xls";            saveDialog.FileName = fileName;            MemoryStream ms = new MemoryStream();            if (saveDialog.ShowDialog() == DialogResult.OK)            {                saveFileName = saveDialog.FileName;                if (!CheckFiles(saveFileName))                {                    MessageBox.Show("文件被站用，请关闭文件 " + saveFileName);                    workbook = null;                    ms.Close();                    ms.Dispose();                    return;                }                workbook.Write(ms);                FileStream file = new FileStream(saveFileName, FileMode.Create);                workbook.Write(file);                file.Close();                workbook = null;                ms.Close();                ms.Dispose();                MessageBox.Show(fileName + " 保存成功", "提示", MessageBoxButtons.OK);            }            else            {                workbook = null;                ms.Close();                ms.Dispose();            }        }        #endregion        #region 检测文件被占用         [DllImport("kernel32.dll")]        public static extern IntPtr _lopen(string lpPathName, int iReadWrite);        [DllImport("kernel32.dll")]        public static extern bool CloseHandle(IntPtr hObject);        public const int OF_READWRITE = 2;        public const int OF_SHARE_DENY_NONE = 0x40;        public readonly IntPtr HFILE_ERROR = new IntPtr(-1);        /// <summary>        /// 检测文件被占用         /// </summary>        /// <param name="FileNames">要检测的文件路径</param>        /// <returns></returns>        public bool CheckFiles(string FileNames)        {            if (!File.Exists(FileNames))            {                //文件不存在                return true;            }            IntPtr vHandle = _lopen(FileNames, OF_READWRITE | OF_SHARE_DENY_NONE);            if (vHandle == HFILE_ERROR)            {                //文件被占用                return false;            }            //文件没被占用            CloseHandle(vHandle);            return true;        }        #endregion

具体效果如下：