//创建饼状图表
Chart chart = sheet.Charts.Add(ExcelChartType.Pie);
//设置图表的数据范围,使用的也是和前面单元格获取的Range对象
chart.DataRange = sheet.Range["B2:B5"];
chart.SeriesDataFromRange = false;

//设置图表的位置
chart.LeftColumn = 1;//图表左边列
chart.TopRow = 6;//图表上部的行
chart.RightColumn = 6;//图表右边列
chart.BottomRow = 18;//图表底部行

//图表标题
chart.ChartTitle = "饼形图例子";
//设置字体
chart.ChartTitleArea.IsBold = true;
chart.ChartTitleArea.Size = 12;

//初始化图例
Spire.Xls.Charts.ChartSerie cs = chart.Series[0];
//图表的标签目录数据
cs.CategoryLabels = sheet.Range["A2:A5"];
//图表的主要值，也就是饼状图的数据
cs.Values = sheet.Range["B2:B5"];

//给Sheet对象添加一个图表对象，可以直接添加类型，也可以单独用ChartType赋值来添加
Chart chart = sheet.Charts.Add();
chart.ChartType = ExcelChartType.Line3D;

//设置图表的数据范围
chart.DataRange = sheet.Range["A1:E5"];

//设置图表的保存位置，这个基本都差不多
chart.LeftColumn = 1;
chart.TopRow = 6;
chart.RightColumn = 7;
chart.BottomRow = 22;

//图表标题
chart.ChartTitle = "折线图例子";
//设置字体加粗和大小
chart.ChartTitleArea.IsBold = true;
chart.ChartTitleArea.Size = 12;
//设置横坐标的标题
chart.PrimaryCategoryAxis.Title = "月份";
chart.PrimaryCategoryAxis.Font.IsBold = true;
chart.PrimaryCategoryAxis.TitleArea.IsBold = true;
//设置纵坐标，也就是值 的标题
chart.PrimaryValueAxis.Title = "销售额";
chart.PrimaryValueAxis.HasMajorGridLines = false;
chart.PrimaryValueAxis.TitleArea.TextRotationAngle = 90;
chart.PrimaryValueAxis.MinValue = 1000;
chart.PrimaryValueAxis.TitleArea.IsBold = true;
//循环绘制不同国家的销售额折线图，有多个系列
foreach (Spire.Xls.Charts.ChartSerie cs in chart.Series)
{
 cs.Format.Options.IsVaryColor = true;
 cs.DataPoints.DefaultDataPoint.DataLabels.HasValue = true;   
}

Workbook workbook = new Workbook();
workbook.LoadFromFile("chart.xlsx", ExcelVersion.Version2010);
Worksheet sheet=workbook.Worksheets[0];
Image[] imgs = workbook.SaveChartAsImage(sheet);
for (int i = 0; i < imgs.Length; i++)
{
 imgs[i].Save(string.Format("img-{0}.png", i), ImageFormat.Png);
}

chart.Width = 400;
chart.Height = 250;