Install-Package Syncfusion.TreeMap.WinForms

using System.Collections.ObjectModel;

public class PopulationDetail
{
    public string Continent { get; set; }
    public string Country { get; set; }
    public double Growth { get; set; }
    public double Population { get; set; }
}

public class PopulationViewModel
{
    public ObservableCollection<PopulationDetail> PopulationDetails { get; set; }
    
    public PopulationViewModel()
    {
        PopulationDetails = new ObservableCollection<PopulationDetail>();
        
        PopulationDetails.Add(new PopulationDetail 
        { 
            Continent = "Asia", 
            Country = "Indonesia", 
            Growth = 3, 
            Population = 237641326 
        });
        
        PopulationDetails.Add(new PopulationDetail 
        { 
            Continent = "Asia", 
            Country = "Russia", 
            Growth = 2, 
            Population = 152518015 
        });
        
        PopulationDetails.Add(new PopulationDetail 
        { 
            Continent = "North America", 
            Country = "United States", 
            Growth = 4, 
            Population = 315645000 
        });
        
        // Add more data...
    }
}

using Syncfusion.Windows.Forms.TreeMap;

public class MyForm : Form
{
    private TreeMap treeMap;
    
    public MyForm()
    {
        InitializeComponent();
        
        // Create TreeMap instance
        treeMap = new TreeMap();
        
        // Set data source
        PopulationViewModel data = new PopulationViewModel();
        treeMap.ItemsSource = data.PopulationDetails;
        
        // Configure paths
        treeMap.WeightValuePath = "Population";
        treeMap.ColorValuePath = "Growth";
        
        // Set layout mode
        treeMap.ItemsLayoutMode = ItemsLayoutModes.Squarified;
        
        // Add first level (Continent)
        TreeMapFlatLevel level1 = new TreeMapFlatLevel();
        level1.GroupPath = "Continent";
        level1.ShowLabels = true;
        treeMap.Levels.Add(level1);
        
        // Add second level (Country)
        TreeMapFlatLevel level2 = new TreeMapFlatLevel();
        level2.GroupPath = "Country";
        level2.ShowLabels = true;
        level2.HeaderHeight = 25;
        treeMap.Levels.Add(level2);
        
        // Add color mapping
        UniColorMapping colorMapping = new UniColorMapping();
        colorMapping.Color = Color.MediumSlateBlue;
        treeMap.LeafColorMapping = colorMapping;
        
        // Set size and add to form
        treeMap.Size = new Size(800, 600);
        treeMap.Location = new Point(10, 10);
        this.Controls.Add(treeMap);
    }
}

// Create levels for nested grouping
TreeMapFlatLevel level1 = new TreeMapFlatLevel();
level1.GroupPath = "Category";
level1.ShowLabels = true;
treeMap.Levels.Add(level1);

TreeMapFlatLevel level2 = new TreeMapFlatLevel();
level2.GroupPath = "SubCategory";
level2.ShowLabels = true;
level2.HeaderHeight = 25;
treeMap.Levels.Add(level2);

TreeMapFlatLevel level3 = new TreeMapFlatLevel();
level3.GroupPath = "Item";
level3.ShowLabels = true;
level3.HeaderHeight = 20;
treeMap.Levels.Add(level3);

RangeBrushColorMapping rangeMapping = new RangeBrushColorMapping();

rangeMapping.Brushes.Add(new RangeBrush 
{ 
    Color = ColorTranslator.FromHtml("#77D8D8"), 
    From = 0, 
    To = 1, 
    LegendLabel = "Low" 
});

rangeMapping.Brushes.Add(new RangeBrush 
{ 
    Color = ColorTranslator.FromHtml("#FFAF51"), 
    From = 1, 
    To = 5, 
    LegendLabel = "Medium" 
});

rangeMapping.Brushes.Add(new RangeBrush 
{ 
    Color = ColorTranslator.FromHtml("#F3D240"), 
    From = 5, 
    To = 20, 
    LegendLabel = "High" 
});

treeMap.LeafColorMapping = rangeMapping;

// Enable tooltips
treeMap.IsToolTipVisible = true;

// Configure header tooltip
ToolTipInfo headerToolTip = new ToolTipInfo();
headerToolTip.ToolTipHeaderPattern = "<b>{Label}</b>";
headerToolTip.ToolTipContentPattern = "Growth: {Growth}%";
treeMap.HeaderToolTipInfo = headerToolTip;

// Configure item tooltip
ToolTipInfo itemToolTip = new ToolTipInfo();
itemToolTip.ToolTipHeaderPattern = "<b>{Country}</b>";
itemToolTip.ToolTipContentPattern = "Growth: {Growth}%\nPopulation: {Population}";
treeMap.ItemToolTipInfo = itemToolTip;