饼图中的自定义切片或扇区颜色

本文介绍如何向饼图切片/扇区添加自定义颜色。默认情况下，饼图使用 Microsoft Excel 默认模板。要使用其他颜色，请重新定义图表中的颜色。

要为饼图的各个切片或扇区设置自定义颜色：

1. 访问系列对象的图表点.
2. 使用分配您选择的颜色ChartPoint.Area.ForegroundColor财产。

本文还解释了如何：

• 图表的类别数据。
• 链接到单元格的图表标题。
• 图表标题字体设置。
• 图例的位置。

ChartPoint.Area.ForegroundColor不特定于饼图，但它可用于所有类型的图表。

// For complete examples and data files, please go to https://github.com/aspose-cells/Aspose.Cells-for-.NET
// The path to the documents directory.
string dataDir = RunExamples.GetDataDir(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

// Create a workbook object from the template file
Workbook workbook = new Workbook();

// Access the first worksheet.
Worksheet worksheet = workbook.Worksheets[0];

// Put the sample values used in a pie chart
worksheet.Cells["C3"].PutValue("India");
worksheet.Cells["C4"].PutValue("China");
worksheet.Cells["C5"].PutValue("United States");
worksheet.Cells["C6"].PutValue("Russia");
worksheet.Cells["C7"].PutValue("United Kingdom");
worksheet.Cells["C8"].PutValue("Others");

// Put the sample values used in a pie chart
worksheet.Cells["D2"].PutValue("% of world population");
worksheet.Cells["D3"].PutValue(25);
worksheet.Cells["D4"].PutValue(30);
worksheet.Cells["D5"].PutValue(10);
worksheet.Cells["D6"].PutValue(13);
worksheet.Cells["D7"].PutValue(9);
worksheet.Cells["D8"].PutValue(13);

// Create a pie chart with desired length and width
int pieIdx = worksheet.Charts.Add(ChartType.Pie, 1, 6, 15, 14);

// Access the pie chart
Chart pie = worksheet.Charts[pieIdx];

// Set the pie chart series
pie.NSeries.Add("D3:D8", true);

// Set the category data
pie.NSeries.CategoryData = "=Sheet1!$C$3:$C$8";

// Set the chart title that is linked to cell D2
pie.Title.LinkedSource = "D2";

// Set the legend position at the bottom.
pie.Legend.Position = LegendPositionType.Bottom;

// Set the chart title's font name and color
pie.Title.Font.Name = "Calibri";
pie.Title.Font.Size = 18;

// Access the chart series
Series srs = pie.NSeries[0];

// Color the indvidual points with custom colors
srs.Points[0].Area.ForegroundColor = System.Drawing.Color.FromArgb(0, 246, 22, 219);
srs.Points[1].Area.ForegroundColor = System.Drawing.Color.FromArgb(0, 51, 34, 84);
srs.Points[2].Area.ForegroundColor = System.Drawing.Color.FromArgb(0, 46, 74, 44);
srs.Points[3].Area.ForegroundColor = System.Drawing.Color.FromArgb(0, 19, 99, 44);
srs.Points[4].Area.ForegroundColor = System.Drawing.Color.FromArgb(0, 208, 223, 7);
srs.Points[5].Area.ForegroundColor = System.Drawing.Color.FromArgb(0, 222, 69, 8);

// Autofit all columns
worksheet.AutoFitColumns();

dataDir = dataDir+ "output.out.xlsx";
// Save the workbook
workbook.Save(dataDir, SaveFormat.Xlsx);