记一次NPOI的使用

以下代码使用的NPOI版本为2.3.0

记录一些NPOI操作的代码

1.读取模板并且获取第一个sheet

string template = ExcelTemplatePath + "PFMEATemplate.xlsx";
FileStream fileStream = new FileStream(template, FileMode.Open, FileAccess.Read);
ISheet sheet = null;
XSSFWorkbook xssfworkbook = new XSSFWorkbook(fileStream);
sheet = xssfworkbook.GetSheetAt(0);

2.读取单元格

IRow Row = sheet.GetRow(i);  //获取行，i=0为第一行
ICell cell = Row.GetCell(j);  //获取单元格，此处为第i行，第j列的单元格
cell.ToString()  //单元格内容
cell.SetCellValue("123"); //给单元格赋值123

3.几个常用的样式

 #region 设置几个常用的样式
            IFont font = xssfworkbook.CreateFont();
            font.FontHeightInPoints = 9;
            font.FontName = "宋体";

            ICellStyle style = xssfworkbook.CreateCellStyle();
            style.BorderBottom = BorderStyle.Thin;
            style.BorderLeft = BorderStyle.Thin;
            style.BorderRight = BorderStyle.Thin;
            style.BorderTop = BorderStyle.Thin;
            style.VerticalAlignment = VerticalAlignment.Center;
            style.Alignment = HorizontalAlignment.Center;
            style.SetFont(font);
            style.WrapText = true;

            ICellStyle styleGreen = xssfworkbook.CreateCellStyle();
            styleGreen.BorderBottom = BorderStyle.Thin;
            styleGreen.BorderLeft = BorderStyle.Thin;
            styleGreen.BorderRight = BorderStyle.Thin;
            styleGreen.BorderTop = BorderStyle.Thin;
            styleGreen.FillPattern = FillPattern.SolidForeground;
            styleGreen.FillForegroundColor = GetXLColour(Color.DarkGreen);
            styleGreen.VerticalAlignment = VerticalAlignment.Center;
            styleGreen.Alignment = HorizontalAlignment.Center;
            styleGreen.SetFont(font);

            ICellStyle styleRed = xssfworkbook.CreateCellStyle();
            styleRed.BorderBottom = BorderStyle.Thin;
            styleRed.BorderLeft = BorderStyle.Thin;
            styleRed.BorderRight = BorderStyle.Thin;
            styleRed.BorderTop = BorderStyle.Thin;
            styleRed.FillPattern = FillPattern.SolidForeground;
            styleRed.FillForegroundColor = GetXLColour(Color.Red);
            styleRed.VerticalAlignment = VerticalAlignment.Center;
            styleRed.Alignment = HorizontalAlignment.Center;
            styleRed.SetFont(font);

            ICellStyle styleYellow = xssfworkbook.CreateCellStyle();
            styleYellow.BorderBottom = BorderStyle.Thin;
            styleYellow.BorderLeft = BorderStyle.Thin;
            styleYellow.BorderRight = BorderStyle.Thin;
            styleYellow.BorderTop = BorderStyle.Thin;
            styleYellow.FillPattern = FillPattern.SolidForeground;
            styleYellow.FillForegroundColor = GetXLColour(Color.Yellow);
            styleYellow.VerticalAlignment = VerticalAlignment.Center;
            styleYellow.Alignment = HorizontalAlignment.Center;
            styleYellow.SetFont(font);

            ICellStyle styleMerage = xssfworkbook.CreateCellStyle();
            styleMerage.BorderBottom = BorderStyle.Thin;
            styleMerage.BorderLeft = BorderStyle.Thin;
            styleMerage.BorderRight = BorderStyle.Thin;
            styleMerage.BorderTop = BorderStyle.Thin;
            styleMerage.VerticalAlignment = VerticalAlignment.Center;
            styleMerage.Alignment = HorizontalAlignment.Center;
            styleMerage.WrapText = true;
            styleMerage.SetFont(font);

            #endregion

ICell cell0 = dataRow.CreateCell(0);
cell0.CellStyle = style;   //给cell0单元格设定style样式

4.加载图片

//加载图片到workbook
public int LoadImage(string pircture, XSSFWorkbook xssfworkbook)
        {
            using (FileStream file = new FileStream(pircture, FileMode.Open, FileAccess.Read))
            {
                byte[] buffer = new byte[file.Length];
                file.Read(buffer, 0, (int)file.Length);
                file.Flush();
                return xssfworkbook.AddPicture(buffer, PictureType.PNG);
            }

        }

//将加载好的图片放到指定单元格
IDrawing drawing = sheet.CreateDrawingPatriarch();  
XSSFClientAnchor anchor = new XSSFClientAnchor(0, 0, 0, 0, picColumn, i+9, picColumn+1, i + 9+1);   //XSSFClientAnchor构造函数的参数依次是图片左上角的单元格x偏移量、y偏移量、图片右下角x偏移量、y偏移量、左上角单元格列、左上角单元格行、右下角单元格列、右下角单元格行
XSSFPicture xssfpicture = (XSSFPicture)drawing.CreatePicture(anchor, picColumn); //pieColumn为LoadImage函数返回的int索引

5.画线

 XSSFDrawing linedrawing = (XSSFDrawing)sheet.CreateDrawingPatriarch();
 XSSFClientAnchor lineAnchor = new XSSFClientAnchor(10, 10, 10, 10, 3, 15, 3, 18); 
 XSSFSimpleShape lineShape = linedrawing.CreateSimpleShape(lineAnchor);
lineShape.ShapeType = 1;
lineShape.SetLineStyleColor(0,0,0);

第4点、第5点有bug，设置的XSSFClientAnchor中的前4个变量偏移量不起作用（如果有哪位大神知道理由请指导），后将

XSSFClientAnchor对象改为HSSFClientAnchor对象，
这两个对象的区别

XSSFClientAnchor对应xlsx后缀

HSSFClientAnchor对应xls后缀
实际使用没有多少差别，生成相同的文件xlsx的大小比xls的大小小一些，实际体验基本没有区别
附上使用HSSFClientAnchor的代码

IDrawing drawing = sheet.CreateDrawingPatriarch();

HSSFClientAnchor anchor = new HSSFClientAnchor(250, 0, 250, 0, picColumn, i + 9, picColumn + 1, i + 9 + 1);
HSSFPicture hssfpicture = (HSSFPicture)drawing.CreatePicture(anchor, picColumn + 1);
hssfpicture.Resize();
//画直线
HSSFPatriarch linedrawing = (HSSFPatriarch)sheet.CreateDrawingPatriarch();
HSSFClientAnchor lineAnchor = new HSSFClientAnchor(500, 220, 500, 0, preCol, preRow, picColumn, i + 9);
HSSFSimpleShape lineShape = linedrawing.CreateSimpleShape(lineAnchor);
lineShape.ShapeType = HSSFSimpleShape.OBJECT_TYPE_LINE;
lineShape.SetLineStyleColor(0, 0, 0);