Create Pie Chart

Introduction

Creating charts is essential for visually representing data, and pie charts are one of the most popular ways to illustrate how parts make up a whole. With Aspose.Cells for .NET, you can easily automate the generation of pie charts in Excel files. In this tutorial, we’ll dive into how to create a pie chart from scratch using Aspose.Cells for .NET, with a step-by-step guide to make the process smooth and straightforward. Whether you’re new to the tool or looking to enhance your Excel automation skills, this guide has you covered!

Prerequisites

Before diving into the code, make sure you have the following set up:

  1. Aspose.Cells for .NET Library: Ensure that you have Aspose.Cells installed in your project. If you haven’t installed it yet, you can download it from here.
  2. .NET Development Environment: Make sure your project is set up to use .NET Framework or .NET Core.
  3. Basic Knowledge of C#: You should be comfortable with C# programming, particularly object-oriented programming (OOP).

For advanced users, a temporary license can be applied to unlock all the features of Aspose.Cells. You can request one from here.

Import Packages

To start, import the necessary namespaces and packages required for this tutorial. These include basic I/O operations and the Aspose.Cells package.

using System;
using System.IO;

using Aspose.Cells;
using Aspose.Cells.Drawing;
using System.Drawing;
using Aspose.Cells.Charts;

Step 1: Create a New Workbook

First, we need to create an instance of the Workbook class, which represents the Excel file. A workbook contains multiple sheets, and for our example, we will be working with two sheets—one for data and one for the pie chart.

Workbook workbook = new Workbook();

This initializes a new Excel workbook. But where does the data go? Let’s take care of that in the next step.

Step 2: Add Data to the Worksheet

Once the workbook is created, we need to access the first worksheet and give it a name. This is where we’ll input the data required for the pie chart.

Worksheet sheet = workbook.Worksheets[0];
sheet.Name = "Data";
Cells cells = sheet.Cells;

Now, we can input some dummy sales data representing different regions:

cells["A1"].PutValue("Region");
cells["A2"].PutValue("France");
cells["A3"].PutValue("Germany");
cells["A4"].PutValue("England");
cells["A5"].PutValue("Sweden");
cells["A6"].PutValue("Italy");
cells["A7"].PutValue("Spain");
cells["A8"].PutValue("Portugal");

cells["B1"].PutValue("Sales");
cells["B2"].PutValue(70000);
cells["B3"].PutValue(55000);
cells["B4"].PutValue(30000);
cells["B5"].PutValue(40000);
cells["B6"].PutValue(35000);
cells["B7"].PutValue(32000);
cells["B8"].PutValue(10000);

Here, we’re adding two columns: one for regions and another for sales figures. This data will be represented in the pie chart.

Step 3: Add a Chart Sheet

Next, let’s add a separate worksheet to hold the pie chart.

int sheetIndex = workbook.Worksheets.Add(SheetType.Chart);
Worksheet chartSheet = workbook.Worksheets[sheetIndex];
chartSheet.Name = "Chart";

This new sheet will host the pie chart. Giving it a name such as “Chart” ensures that users know what to expect when they open the file.

Step 4: Create the Pie Chart

Now it’s time to create the actual chart. We’ll specify that we want a pie chart, and we’ll define its position on the sheet.

int chartIndex = chartSheet.Charts.Add(Aspose.Cells.Charts.ChartType.Pie, 5, 0, 25, 10);
Aspose.Cells.Charts.Chart chart = chartSheet.Charts[chartIndex];

The method Add() accepts parameters for the chart type (in this case, ChartType.Pie), and its location on the worksheet. The numbers represent row and column positions.

Step 5: Customize the Chart Appearance

A pie chart wouldn’t be complete without some customization! Let’s make our chart visually appealing by tweaking the colors, labels, and title.

Set Chart Title

chart.Title.Text = "Sales By Region";
chart.Title.Font.Color = Color.Blue;
chart.Title.Font.IsBold = true;
chart.Title.Font.Size = 12;

Customize Plot Area

chart.PlotArea.Area.ForegroundColor = Color.Coral;
chart.PlotArea.Area.FillFormat.SetTwoColorGradient(Color.Yellow, Color.White, GradientStyleType.Vertical, 2);
chart.PlotArea.Border.IsVisible = false;

We set the gradient fill for the plot area and hide the border for a cleaner look.

Step 6: Define Chart Data

It’s time to link the chart to our data. The NSeries property of the chart binds the sales figures and regions to the pie chart.

chart.NSeries.Add("Data!B2:B8", true);
chart.NSeries.CategoryData = "Data!A2:A8";
chart.NSeries.IsColorVaried = true;

The first line specifies that we’re using the sales data from cells B2:B8. We also tell the chart to use the region names from A2:A8 as category labels.

Step 7: Add Data Labels

Adding labels directly to the chart segments can make it easier to understand. Let’s include the region names and sales values within the pie chart slices.

for (int i = 0; i < chart.NSeries.Count; i++)
{
    DataLabels labels = chart.NSeries[i].DataLabels;
    labels.ShowCategoryName = true;
    labels.ShowValue = true;
    labels.Position = LabelPositionType.InsideBase;
}

Step 8: Customize Chart Area and Legend

Lastly, let’s give the chart area and legend some final touches. This enhances the overall presentation of the chart.

Chart Area

ChartArea chartArea = chart.ChartArea;
chartArea.Area.Formatting = FormattingType.Custom;
chartArea.Area.FillFormat.Texture = TextureType.BlueTissuePaper;

Legend

Legend legend = chart.Legend;
legend.Position = LegendPositionType.Left;
legend.Font.IsBold = true;
legend.Border.Color = Color.Blue;
legend.Area.FillFormat.Texture = TextureType.Bouquet;

Step 9: Save the Workbook

Finally, we save the workbook to an Excel file. You can specify the output directory and filename as needed.

workbook.Save(outputDir + "outputHowToCreatePieChart.xlsx");

Conclusion

Creating a pie chart with Aspose.Cells for .NET is a straightforward and customizable process. By following this guide, you can generate a professional-looking chart that conveys valuable insights in just a few steps. Whether for business reporting or educational purposes, mastering chart creation will elevate your Excel automation skills. Remember, Aspose.Cells provides the flexibility you need to create stunning, data-driven Excel files effortlessly.

FAQ’s

Can I create other types of charts using Aspose.Cells for .NET?

Yes! Aspose.Cells supports various chart types, including bar charts, line charts, and scatter plots.

Do I need a paid license to use Aspose.Cells for .NET?

You can use the free version with some limitations. For full features, you’ll need a license, which you can buy here.

Can I export the chart to formats like PDF or images?

Absolutely! Aspose.Cells allows you to export charts to various formats, including PDF and PNG.

Is it possible to style each pie slice with different colors?

Yes, you can apply different colors to each slice by setting the IsColorVaried property to true, as shown in the tutorial.

Can I automate the generation of multiple charts in a single workbook?

Yes, you can create and customize as many charts as needed within a single Excel file.

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