public class TreeListDocumentExportCustomizePageHeaderFooterEventArgs :
    GridDocumentExportCustomizePageHeaderFooterEventArgsBase

@rendermode InteractiveServer
@using DevExpress.Drawing
@inject SpaceObjectDataProvider SpaceObjectDataProvider

<DxTreeList @ref="TreeList" Data="TreeListData" ChildrenFieldName="Satellites">
    <Columns>
        <DxTreeListDataColumn FieldName="Name" />
        <DxTreeListDataColumn FieldName="TypeOfObject" Caption="Type" />
        <DxTreeListDataColumn FieldName="Mass10pow21kg" Caption="Mass, kg" DisplayFormat="N2" />
        <DxTreeListDataColumn FieldName="MeanRadiusInKM" Caption="Radius, km" DisplayFormat="N2"/>
    </Columns>
    <ToolbarTemplate>
        <DxToolbar>
            <DxToolbarItem Text="Export to PDF" Click="ExportPdf_Click" BeginGroup="true" />
        </DxToolbar>
    </ToolbarTemplate>
</DxTreeList>

@code {
    ITreeList TreeList { get; set; }
    object TreeListData { get; set; }
    DXFont defaultFont = new DXFont("Times New Roman", 12, DXFontStyle.Regular);

    protected override async Task OnInitializedAsync() {
        TreeListData = SpaceObjectDataProvider.GenerateData();
    }
    async Task ExportPdf_Click() {
        await TreeList.ExportToPdfAsync("ExportResult", new TreeListPdfExportOptions() {
            CustomizeDocument = OnCustomizeDocument, // Customizes exported document appearance
            CustomizeDocumentHeader = OnCustomizeDocumentHeader, // Adds a document header
            CustomizeDocumentFooter = OnCustomizeDocumentFooter, // Adds a document footer
            CustomizePageHeader = OnCustomizePageHeader, // Adds page headers
            CustomizePageFooter = OnCustomizePageFooter, // Adds page footers
        });
    }
    void OnCustomizeDocument(TreeListDocumentExportCustomizeDocumentEventArgs args) {
        args.DefaultElementStyle.Font = defaultFont;
        args.PaperKind = DevExpress.Drawing.Printing.DXPaperKind.B5;
    }
    void OnCustomizeDocumentHeader(TreeListDocumentExportCustomizeDocumentHeaderFooterEventArgs args) {
        args.ElementStyle.Font = new DXFont("Arial", 16);
        args.Text = "Space Objects";
    }
    void OnCustomizeDocumentFooter(TreeListDocumentExportCustomizeDocumentHeaderFooterEventArgs args) {
        args.ElementStyle.Font = new DXFont(defaultFont.Name, defaultFont.Size, DXFontStyle.Bold);
        args.ElementStyle.TextAlignment = DevExpress.XtraPrinting.TextAlignment.MiddleLeft;
        args.Text = "The document data is intented for demonstration purposes only.";
    }
    void OnCustomizePageHeader(TreeListDocumentExportCustomizePageHeaderFooterEventArgs args) {
        args.ElementStyle.Font = new DXFont(defaultFont.Name, defaultFont.Size, DXFontStyle.Italic);
        args.Text = "Copyright © 1998-2025 Developer Express Inc.";
    }
    void OnCustomizePageFooter(TreeListDocumentExportCustomizePageHeaderFooterEventArgs args) {
        args.ElementStyle.Font = new DXFont(defaultFont.Name, defaultFont.Size, DXFontStyle.Italic);
        args.Text = "Page {0} of {1}";
    }
}

using System.Collections.Generic;

public class SpaceObject {
    public string Name { get; set; }
    public double MeanRadiusInKM { get; set; }
    public double Volume10pow9KM3 { get; set; }
    public double Mass10pow21kg { get; set; }
    public double Density { get; set; }
    public double SurfaceGravity { get; set; }
    public string TypeOfObject { get; set; }
    public List<SpaceObject> Satellites { get; set; }
    public SpaceObject(
        string name,
        double meanRadiusInKM,
        double volume10pow9KM3,
        double mass10pow21kg,
        double density,
        double surfaceGravity,
        string typeOfObject,
        List<SpaceObject> satellites = null
    ) {
        Name = name;
        MeanRadiusInKM = meanRadiusInKM;
        Volume10pow9KM3 = volume10pow9KM3;
        Mass10pow21kg = mass10pow21kg;
        Density = density;
        SurfaceGravity = surfaceGravity;
        TypeOfObject = typeOfObject;
        Satellites = satellites ?? new List<SpaceObject>();
    }
}

public class SpaceObjectDataProvider {
    public List<SpaceObject> GenerateData() {
        return new List<SpaceObject>() {
            new SpaceObject("Sun", 696000, 1412000000, 1989100000, 1.409, 274.0, "Star", new List<SpaceObject>() {
                new SpaceObject("Mercury", 2439.7, 60.83, 330.2, 5.43, 3.7, "Planet"),
                new SpaceObject("Venus", 6051.8, 928.43, 4868.5, 5.24, 8.872, "Planet"),
                new SpaceObject("Earth", 6371.0, 1083.21, 5973.6, 5.515, 9.78033, "Planet", new List<SpaceObject> () {
                    new SpaceObject("Moon", 1737.1, 21.958, 73.5, 3.3464, 1.625, "Satellite")
                }),
                new SpaceObject("Mars", 3390.0, 163.18, 641.85, 3.94, 3.7, "Planet"),
                new SpaceObject("Jupiter", 69911, 1431280, 1898600, 1.33, 24.79, "Planet", new List<SpaceObject>() {
                    new SpaceObject("Ganymede", 2631.2, 76.30, 148.2, 1.936, 1.428, "Satellite"),
                    new SpaceObject("Callisto", 2410.3, 58.65, 107.6, 1.83, 1.23603, "Satellite"),
                    new SpaceObject("Io", 1821.5, 25.32, 89.3, 3.528, 1.797, "Satellite"),
                    new SpaceObject("Europa", 1561, 15.93, 48, 3.01, 1.316, "Satellite"),
                }),
                new SpaceObject("Saturn", 58232, 827130, 568460, 0.70, 10.445, "Planet", new List<SpaceObject>() {
                    new SpaceObject("Titan", 2576, 71.52, 134.5, 1.88, 1.354, "Satellite"),
                    new SpaceObject("Rhea", 764.4, 1.87, 2.3166, 1.23, 0.26, "Satellite"),
                    new SpaceObject("Iapetus", 736, 1.55, 1.9739, 1.08, 0.223, "Satellite"),
                    new SpaceObject("Dione", 561.6, 0.73, 1.096, 1.48, 0.232, "Satellite"),
                    new SpaceObject("Tethys", 533, 0.624, 0.6173, 1.15, 0.145, "Satellite"),
                    new SpaceObject("Enceladus", 252.1, 0.067, 0.108, 1.61, 0.111, "Satellite"),
                    new SpaceObject("Mimas", 198.3, 0.033, 0.03749, 1.15, 0.06363, "Satellite")
                }),
                new SpaceObject("Uranus", 25362, 68340, 86832, 1.30, 8.87, "Planet", new List<SpaceObject>() {
                    new SpaceObject("Titania", 788.9, 2.06, 3.526, 1.72, 0.378, "Satellite"),
                    new SpaceObject("Oberon", 761.4, 1.85, 3.014, 1.63, 0.347, "Satellite"),
                    new SpaceObject("Umbriel", 584.7, 0.84, 1.2, 1.4, 0.234, "Satellite"),
                    new SpaceObject("Ariel", 578.9, 0.81, 1.35, 1.67, 0.269, "Satellite"),
                    new SpaceObject("Miranda", 235.8, 0.055, 0.0659, 1.20, 0.07910375, "Satellite"),
                }),
                new SpaceObject("Neptune", 24622, 62540, 102430, 1.76, 11.15, "Planet", new List<SpaceObject>() {
                    new SpaceObject("Triton", 1353.4, 10.38, 21.5, 2.061, 0.782, "Satellite"),
                    new SpaceObject("Proteus", 210, 0.038, 0.050, 1.3, 0.0666, "Satellite"),
                }),
                new SpaceObject("Eris", 1170, 7, 16.7, 2.25, 0.662, "Dwarf planet"),
                new SpaceObject("Pluto", 1153, 7.15, 13.105, 2.0, 0.61, "Dwarf planet"),
                new SpaceObject("Makemake", 710, 1.8, 3, 2.0, 0.4, "Dwarf planet"),
                new SpaceObject("Haumea", 575, 1.3, 4.006, 3, 0.44, "Dwarf planet"),
                new SpaceObject("Ceres", 475, 0.437, 0.95, 2.08, 0.27, "Dwarf planet"),
                new SpaceObject("Pallas", 266, 0.078, 0.211, 2.8, 0.2, "Asteroid"),
                new SpaceObject("Vesta", 264.6, 0.078, 0.262, 3.42, 0.251, "Asteroid")
            })
        };
    }
}

// ...
builder.Services.AddSingleton<SpaceObjectDataProvider>();