NPOI-Excel合并单元格后的边框设置

一个问题

用NPOI合并Excel单元格后，其边框如何设置，这个问题困扰了有段时间。因为不怎么看文档，只能在网上搜索。但基本上都是用HSSFWorkbook针对的xls文件，对xlsx文件的则没有。此外还有一些用循环做的，更是舍近求远。

用RegionUtil.SetBorderXXX解决

1、引用

using NPOI.SS.Util;

2、合并单元格

CellRangeAddress region = new CellRangeAddress(1, 2, i, i);
sheet.AddMergedRegion(region);//合并单元格。

3、设置框线

 RegionUtil.SetBorderLeft(1, region, sheet, workbook)//左
 RegionUtil.SetBorderRight(1, region, sheet, workbook)//右
 RegionUtil.SetBorderTop(1, region, sheet, workbook)//顶
 RegionUtil.SetBorderBottom(1, region, sheet, workbook)//底

附：

namespace NPOI.SS.Util
{
    public class RegionUtil
    {
        public static void SetBorderBottom(int border, CellRangeAddress region, ISheet sheet, IWorkbook workbook);
        public static void SetBorderLeft(int border, CellRangeAddress region, ISheet sheet, IWorkbook workbook);
        public static void SetBorderRight(int border, CellRangeAddress region, ISheet sheet, IWorkbook workbook);
        public static void SetBorderTop(int border, CellRangeAddress region, ISheet sheet, IWorkbook workbook);
        public static void SetBottomBorderColor(int color, CellRangeAddress region, ISheet sheet, IWorkbook workbook);
        public static void SetLeftBorderColor(int color, CellRangeAddress region, ISheet sheet, IWorkbook workbook);
        public static void SetRightBorderColor(int color, CellRangeAddress region, ISheet sheet, IWorkbook workbook);
        public static void SetTopBorderColor(int color, CellRangeAddress region, ISheet sheet, IWorkbook workbook);
    }
}