用WPF做报表控件（五）

导出Excel表格

导出Excel表格可以使用Office的插件，但我们现场用的电脑不一定是装过Office的，所以也就不能用Office的插件。一开始，我采用了csv格式的文件，直接把后缀改成了xls。这样Excel当然是会打开的。但csv格式太过简单，打开的时候往往不怎么好看。后来终于找到了NPOI这个第三方库，用起来还不错。

部分代码如下：

public static MemoryStream DataTableToExcel(DataTable OriginData, DataTable StatisticData, HeaderClass header)
{
    try
    {
        HSSFWorkbook workbook = new HSSFWorkbook();
        sheet = (HSSFSheet)workbook.CreateSheet();
        HSSFFont font = (HSSFFont)workbook.CreateFont();
        font.FontHeightInPoints = 20;
        font.Boldweight = 700;
        HSSFFont fontt = (HSSFFont)workbook.CreateFont();
        fontt.FontHeightInPoints = 12;
        fontt.Boldweight = 700;
        style = GetCellStyle(workbook, null, null, FillPatternType.NO_FILL, null, HorizontalAlignment.CENTER, VerticalAlignment.CENTER, false, false);
        titleStyle = GetCellStyle(workbook, fontt, null, FillPatternType.NO_FILL, null, HorizontalAlignment.CENTER, VerticalAlignment.CENTER, false, true);
        headStyle = GetCellStyle(workbook, font, null, FillPatternType.NO_FILL, null, HorizontalAlignment.CENTER, VerticalAlignment.CENTER, false, false);
        dateStyle = GetCellStyle(workbook, null, null, FillPatternType.NO_FILL, null, HorizontalAlignment.CENTER, VerticalAlignment.CENTER, true, false);

        int i = 0;
        int j = 0;

        #region 新建表，填充表头，填充列头，样式

        InitHeader(header, OriginData);

        #endregion

        #region 填充内容

        for (i = 0; i < OriginData.Rows.Count; i++)
        {
            HSSFRow dataRow = (HSSFRow)sheet.CreateRow(total_row + i);
            for (j = 0; j < OriginData.Columns.Count; j++)
            {
                HSSFCell newCell = (HSSFCell)dataRow.CreateCell(j);
                string drValue = OriginData.Rows[i][j].ToString();
                switch (j)
                {
                    case 0:
                        DateTime dateV;
                        DateTime.TryParse(drValue, out dateV);
                        newCell.SetCellValue(dateV);
                        newCell.CellStyle = dateStyle;
                        break;
                    default:
                        newCell.SetCellValue(drValue);
                        newCell.CellStyle = style;
                        break;
                }
                Global.mWaitWnd.ShowProgress(OriginData.Rows.Count, i);
            }
        }

        #endregion

        #region 填充统计值

        if (StatisticData != null)
        {
            for (i = 0; i < 4; i++)
            {
                HSSFRow dataRowS = (HSSFRow)sheet.CreateRow(total_row + OriginData.Rows.Count + i);
                for (j = 0; j < StatisticData.Columns.Count; j++)
                {
                    HSSFCell newCell = (HSSFCell)dataRowS.CreateCell(j);
                    string drValue = StatisticData.Rows[i][j].ToString();
                    newCell.SetCellValue(drValue);
                    newCell.CellStyle = style;
                }
            }
        }
        Global.mWaitWnd.ShowProgress(100, 100);

        #endregion

        #region 写入文件

        using (MemoryStream ms = new MemoryStream())
        {
            workbook.Write(ms);
            ms.Flush();
            ms.Position = 0;
            sheet.Dispose();
            return ms;
        }

        #endregion
    }
    catch (Exception ex)
    {
        System.Windows.MessageBox.Show(ex.ToString());
        return null;
    }
}