Create Gantt Chart in Excel using C#

create-gantt-chart-in-excel-using-csharp.md

Learn how to Create Gantt Chart in Excel using C#

create-gantt-chart-in-excel-using-csharp_code.cs

using Aspose.Cells;
using Aspose.Cells.Charts;

// Load the Excel file
Workbook workbook = new Workbook("sample-data.xlsx");
Worksheet sheet = workbook.Worksheets[0];

// Add Gantt Chart
int chartIndex = sheet.Charts.Add(ChartType.BarStacked, 7, 0, 30, 10);
Chart chart = sheet.Charts[chartIndex];
chart.Title.Text = "Gantt Chart";

// Add offset and duration as series
chart.NSeries.Add("D2:D6", true); // Start Offset
chart.NSeries.Add("C2:C6", true); // Duration

// Set task names as categories
chart.NSeries.CategoryData = "A2:A6";

// Make offset bars invisible
chart.NSeries[0].Area.Formatting = FormattingType.None;

// Style duration bars
chart.NSeries[1].Area.Formatting = FormattingType.Custom;
chart.NSeries[1].Area.ForegroundColor = Color.SteelBlue;
chart.NSeries[1].DataLabels.ShowValue = true;

// Axis settings
chart.CategoryAxis.IsPlotOrderReversed = true;
chart.CategoryAxis.Title.Text = "Tasks";
chart.ValueAxis.Title.Text = "Days from Start";
chart.ValueAxis.MajorGridLines.IsVisible = true;

// Hide legend
chart.ShowLegend = false;

// Resize chart (optional)
chart.ChartObject.Width = 700;
chart.ChartObject.Height = 400;

// Save the result
workbook.Save("GanttChartResult.xlsx", SaveFormat.Xlsx);

create-gantt-chart-in-excel-using-csharp_customize.cs

using Aspose.Cells;
using Aspose.Cells.Charts;

// Initialize workbook and worksheet
Workbook workbook = new Workbook();
Worksheet sheet = workbook.Worksheets[0];
sheet.Name = "Gantt Data";

// Sample Task Data with Dates
DateTime projectStart = new DateTime(2025, 4, 1);

// Headers
sheet.Cells["A1"].PutValue("Task");
sheet.Cells["B1"].PutValue("Start Date");
sheet.Cells["C1"].PutValue("Duration (Days)");
sheet.Cells["D1"].PutValue("Start Offset");
sheet.Cells["E1"].PutValue("End Date");

// Data
string[,] tasks = {
        { "Task 1", "2025-04-01", "3" },
        { "Task 2", "2025-04-03", "6" },
        { "Task 3", "2025-04-08", "10" },
        { "Task 4", "2025-04-18", "3" },
        { "Task 5", "2025-04-21", "5" }
    };

for (int i = 0; i < tasks.GetLength(0); i++)
{
    int row = i + 1 + 1; // Start from row 2

    sheet.Cells[row, 0].PutValue(tasks[i, 0]); // Task Name
    sheet.Cells[row, 1].PutValue(DateTime.Parse(tasks[i, 1])); // Start Date
    sheet.Cells[row, 2].PutValue(int.Parse(tasks[i, 2])); // Duration

    // Offset: = StartDate - ProjectStartDate
    sheet.Cells[row, 3].Formula = $"=B{row + 1} - DATE(2025,4,1)";
    sheet.Cells[row, 4].Formula = $"=B{row + 1} + C{row + 1}";
}

// Autofit
sheet.AutoFitColumns();

// Add a chart
int chartIndex = sheet.Charts.Add(ChartType.BarStacked, 10, 0, 30, 10);
Chart chart = sheet.Charts[chartIndex];
chart.Title.Text = "Project Gantt Chart";

// Add Series: Offset (invisible), Duration (visible)
chart.NSeries.Add("D2:D6", true); // Offset
chart.NSeries.Add("C2:C6", true); // Duration

// Set category labels
chart.NSeries.CategoryData = "A2:A6";

// Make Offset series transparent
chart.NSeries[0].Area.Formatting = FormattingType.None;

// Color each task bar differently
Series durationSeries = chart.NSeries[1];
for (int i = 0; i < durationSeries.Points.Count; i++)
{
    durationSeries.Points[i].Area.ForegroundColor = Color.FromArgb(255, 100 + i * 30, 150); // Gradient color variation
}

// Show data labels
chart.NSeries[1].DataLabels.ShowValue = true;


// Axis Settings
chart.CategoryAxis.Title.Text = "Tasks";
chart.CategoryAxis.IsPlotOrderReversed = true;
chart.ValueAxis.Title.Text = "Days from Project Start";
chart.ValueAxis.MajorGridLines.IsVisible = true;
chart.ValueAxis.MinValue = 0;
chart.ValueAxis.MajorUnit = 5;

// Remove Legend
chart.ShowLegend = false;

// Resize chart
chart.ChartObject.Width = 700;
chart.ChartObject.Height = 400;

// Export to Excel
workbook.Save("CustomizedGanttChart.xlsx", SaveFormat.Xlsx);