GridDocumentExportCustomizeColumnEventArgsBase.ColumnIndex Property

Returns the column position in the exported document.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v25.1.dll

NuGet Package: DevExpress.Blazor

Declaration

public int ColumnIndex { get; }

Property Value

Type	Description
Int32	A zero-based column index.

Remarks

The CustomizeColumn event occurs for each data column whose ExportEnabled property is set to true (default).

Use the ColumnIndex event argument to obtain the column position in the output table. When determining this index, the export engine counts only already exported columns (ignores columns whose IsHidden argument was set to true). As a result, the ColumnIndex reflects the actual position in the exported column collection.

Grid Example

The following example exports Grid data to PDF and customizes output table appearance:

Razor

@rendermode InteractiveServer
@using DevExpress.Drawing;
@inject WeatherForecastService ForecastService

<DxGrid @ref="Grid" Data="@forecasts">
    <Columns>
        <DxGridDataColumn Caption="Date" FieldName="Date" />
        <DxGridDataColumn Caption="Summary" FieldName="Summary" />
        <DxGridDataColumn Caption="Temperature (C)" FieldName="TemperatureC" />
        <DxGridDataColumn Caption="Temperature (F)" FieldName="TemperatureF" Visible="false" />
    </Columns>
    <ToolbarTemplate>
        <DxToolbar>
            <DxToolbarItem Text="Export to PDF" Click="ExportPdf_Click" BeginGroup="true" />
        </DxToolbar>
    </ToolbarTemplate>
</DxGrid>

@code {
    IGrid Grid;
    private WeatherForecast[]? forecasts;

    protected override async Task OnInitializedAsync() {
        forecasts = await ForecastService.GetForecastAsync(DateOnly.FromDateTime(DateTime.Now));
    }
    async Task ExportPdf_Click() {
        await Grid.ExportToPdfAsync("ExportResult", new GridPdfExportOptions() {
            FitToPage = false,
            CustomizeColumn = OnCustomizeColumn,
        });
    }
    void OnCustomizeColumn(GridDocumentExportCustomizeColumnEventArgs args) {
        args.Width = 400;
        args.IsHidden = false;
        if (args.ColumnIndex % 2 == 1)
            args.DataCellStyle.BackColor = System.Drawing.Color.LightGray;
        if (args.FieldName == "Date")
            args.DataCellStyle.Font = new DXFont(args.DataCellStyle.Font, DXFontStyle.Bold);
    }
}

WeatherForecast.cs

using System;

public class WeatherForecast {
    public DateTime Date { get; set; }
    public int TemperatureC { get; set; }
    public string Forecast { get; set; }
    public string CloudCover { get; set; }
}

WeatherForecastService.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

public class WeatherForecastService {
    private List<WeatherForecast> Forecast { get; set; }

    private static string[] CloudCover = new[] {
        "Sunny", "Partly cloudy", "Cloudy", "Storm"
    };

    Tuple<int, string>[] ConditionsForForecast = new Tuple<int, string>[] {
        Tuple.Create( 22 , "Hot"),
        Tuple.Create( 13 , "Warm"),
        Tuple.Create( 0 , "Cold"),
        Tuple.Create( -10 , "Freezing")
    };

    public WeatherForecastService() {
        Forecast = CreateForecast();
    }

    private List<WeatherForecast> CreateForecast() {
        var rng = new Random();
        DateTime startDate = DateTime.Now;
        return Enumerable.Range(1, 30).Select(index => {
            var temperatureC = rng.Next(-10, 30);
            return new WeatherForecast {
                Date = startDate.AddDays(index),
                TemperatureC = temperatureC,
                CloudCover = CloudCover[rng.Next(0, 4)],
                Forecast = ConditionsForForecast.First(c => c.Item1 <= temperatureC).Item2
            };
        }).ToList();
    }

    public List<WeatherForecast> GetForecast() {
        return Forecast;
    }

    public Task<WeatherForecast[]> GetForecastAsync(CancellationToken ct = default) {
        return Task.FromResult(Forecast.ToArray());
    }
}

Program.cs

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

TreeList Example

The following example exports TreeList data to PDF and customizes output table appearance:

Razor

@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" />
        <DxTreeListDataColumn FieldName="Volume10pow9KM3" Caption="Volume, km³" DisplayFormat="N2" Visible="false" />
        <DxTreeListDataColumn FieldName="SurfaceGravity" Caption="Gravity" DisplayFormat="N2" Visible="false" />
    </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; }
    protected override async Task OnInitializedAsync() {
        TreeListData = SpaceObjectDataProvider.GenerateData();
    }
    async Task ExportPdf_Click() {
        await TreeList.ExportToPdfAsync("ExportResult", new TreeListPdfExportOptions() {
            FitToPage = false,
            CustomizeColumn = OnCustomizeColumn,
        });
    }
    void OnCustomizeColumn (TreeListDocumentExportCustomizeColumnEventArgs args) {
        args.Width = 300;
        args.IsHidden = false;
        if (args.ColumnIndex % 2 == 1)
            args.DataCellStyle.BackColor = System.Drawing.Color.LightGray;
        if (args.FieldName == "Name") {
            args.DataCellStyle.Font = new DXFont(args.DataCellStyle.Font, DXFontStyle.Bold);
            args.Width = 400;
        }
    }
}

SpaceObject

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>();
    }
}

SpaceObjectDataProvider

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")
            })
        };
    }
}

Program.cs

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