一、思路： 1、excel是可以通过NPOI插入图片的；
2、C#通过NPOI生成饼状图；
3、把生成的饼状图以字节流的形式插入到表格
二、看代码：
#region 生成饼图图例/// <summary>/// 生成饼图饼图的颜色随机产生/// </summary>/// <param name="width">图片宽度</param>/// <param name="height">图片高度</param>/// <param name="radius">饼图半径</param>/// <param name="data">数据源</param>/// <param name="legends">图例</param>/// <returns></returns>public static Bitmap GetPieGraphic(int width, int height, int radius, float[] data, string[] legends){if (data != null){string familyName = "Arial";Bitmap objbitmap = new Bitmap(width, height);Graphics objgraphics = Graphics.FromImage(objbitmap);objgraphics.Clear(Color.White);//抗锯齿 objgraphics.SmoothingMode = SmoothingMode.HighQuality;//高质量的文字 objgraphics.TextRenderingHint = TextRenderingHint.ClearTypeGridFit;//像素均偏移0.5个单位，以消除锯齿 objgraphics.PixelOffsetMode = PixelOffsetMode.Half;//定位饼图绘制的位置Rectangle rect = new Rectangle(width / 2, height / 6, radius, radius);Random random = new Random();float currentdegree = 0.0f;float Total = data.Sum();List<Color> listColor =new List<Color>();for (int i = 0; i < data.Length; i++){Color temC = Color.FromArgb(random.Next(255), random.Next(255), random.Next(255));listColor.Add(temC);SolidBrush brush = new SolidBrush(temC);objgraphics.FillPie(brush, rect, currentdegree, Convert.ToSingle(data[i] / Total * 360));currentdegree += Convert.ToSingle(data[i] / Total * 360);}//放置图例 PointF basePoint = new PointF(10, 20);//色块的大小 SizeF theSize = new SizeF(45, 16);//第一个色块的说明文字的位置PointF textPoint = new PointF(basePoint.X + 50, basePoint.Y);for (int j = 0; j < listColor.Count; j++){RectangleF baseRectangle = new RectangleF(basePoint, theSize);//画代表色块 objgraphics.FillRectangle(new SolidBrush(listColor[j]), baseRectangle);string temstr = String.Format("{0}%", (data[j] / Total * 100).ToString("#0.00"));objgraphics.DrawString(legends[j] + " " + temstr, new Font(familyName, 11), Brushes.Black, textPoint);basePoint.Y += 30;textPoint.Y += 30;}return objbitmap;}else{return null;}}/// <summary>/// 将BitMap类型的图像数据转换成byte[]/// </summary>/// <param name="bitmap">图像数据</param>/// <returns></returns>public static byte[] Bitmap2Byte(Bitmap bitmap){using (MemoryStream stream = new MemoryStream()){bitmap.Save(stream, ImageFormat.Jpeg);byte[] data = new byte[stream.Length];stream.Seek(0, SeekOrigin.Begin);stream.Read(data, 0, Convert.ToInt32(stream.Length));return data;}}#endregion 生成饼图图例
三、在处理表格数据出插入下面代码：
//legends和data可以是动态数据String[] legends = {"A满意","B基本满意","C不满意" };float[] data = {1,3,1 };Bitmap bitmap = GetPieGraphic(200,200,100,data,legends);var row101 = sheet.CreateRow(82);row101.Height = 80 * 20;//将图片文件读入一个字符串byte[] bytes = Bitmap2Byte(bitmap);int pictureIdx = workbook.AddPicture(bytes, PictureType.JPEG);HSSFPatriarch patriarch = (HSSFPatriarch)sheet.CreateDrawingPatriarch();// 插图片的位置 HSSFClientAnchor（dx1,dy1,dx2,dy2,col1,row1,col2,row2) 后面再作解释HSSFClientAnchor anchor = new HSSFClientAnchor(100, 100, 0, 0, 1, 82, 6, 94);//把图片插到相应的位置HSSFPicture pict = (HSSFPicture)patriarch.CreatePicture(anchor, pictureIdx);
