GridDocumentExportCustomizeCellEventArgsBase.DataItem Property

Returns the data item bound to the processed data row.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v25.1.dll

NuGet Package: DevExpress.Blazor

Declaration

public object DataItem { get; }

Property Value

Type	Description
Object	If the processed cell belongs to a data row, the property returns the data item bound to this row. Otherwise, the property returns null.

Remarks

When exporting Grid/TreeList data to PDF, handle the CustomizeCell event to customize table cells in the output file. Use the DataItem event argument to obtain the item bound to the processed data row. This argument returns null if the cell does not belong to a data row (the AreaType argument returns a value other than DataArea).

Pass the DataItem to the GetDataItemValue method to get the item’s field value when the component is bound to one of the following data sources:

• A collection of anonymous objects
• An Instant Feedback Data Source whose AreSourceRowsThreadSafe option is set to false (its default value)

In other cases, you can cast the DataItem to the corresponding type and use the {DataItem.FieldName} notation to get the item’s field value.

Grid Example

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

Razor

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

<DxGrid @ref="Grid" Data="@forecasts" ShowGroupPanel="true">
    <Columns>
        <DxGridDataColumn Caption="Date" FieldName="Date" />
        <DxGridDataColumn Caption="Temperature (C)" FieldName="TemperatureC" ExportWidth="300"/>
        <DxGridDataColumn Caption="Temperature (F)" FieldName="TemperatureF" ExportWidth="300" />
        <DxGridDataColumn Caption="Summary" FieldName="Summary" GroupIndex="0" />
    </Columns>
    <TotalSummary>
        <DxGridSummaryItem SummaryType="GridSummaryItemType.Count" FieldName="Date" />
        <DxGridSummaryItem SummaryType="GridSummaryItemType.Min" FieldName="TemperatureC" />
        <DxGridSummaryItem SummaryType="GridSummaryItemType.Max" FieldName="TemperatureC" />
    </TotalSummary>
    <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() {
            CustomizeCell = OnCustomizeCell,
        });
    }
    void OnCustomizeCell(GridDocumentExportCustomizeCellEventArgs args) {
        if (args.AreaType == DocumentExportAreaType.Header){
            args.ElementStyle.TextAlignment = DevExpress.XtraPrinting.TextAlignment.MiddleCenter;
            args.ElementStyle.Font = new DXFont("Arial", 10, DXFontStyle.Bold);
        }
        if (args.AreaType == DocumentExportAreaType.GroupHeader && args.GroupFieldName == "Summary")
            args.Text = args.Value + ":";
        if (args.AreaType == DocumentExportAreaType.DataArea) {
            args.ElementStyle.BackColor = System.Drawing.Color.MintCream;
            if (args.ColumnFieldName.Contains("Temperature")) {
                var forecast = (WeatherForecast)args.DataItem;
                if (forecast.TemperatureC < 0)
                    args.ElementStyle.ForeColor = System.Drawing.Color.Blue;
                if (forecast.TemperatureC > 30)
                    args.ElementStyle.ForeColor = System.Drawing.Color.Red;
            }
        }
        if (args.AreaType == DocumentExportAreaType.TotalFooter && args.ColumnFieldName == "TemperatureC") {
            args.Text = args.SummaryItems[0].Text + "°C\n" + args.SummaryItems[1].Text + "°C";
            args.ElementStyle.TextAlignment = DevExpress.XtraPrinting.TextAlignment.MiddleRight;
        }
        args.Handled = true;
    }
}

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 the 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" />
    </Columns>
    <TotalSummary>
        <DxTreeListSummaryItem SummaryType="TreeListSummaryItemType.Count" FieldName="Name" />
        <DxTreeListSummaryItem SummaryType="TreeListSummaryItemType.Min" FieldName="MeanRadiusInKM" />
        <DxTreeListSummaryItem SummaryType="TreeListSummaryItemType.Max" FieldName="MeanRadiusInKM" />
    </TotalSummary>
    <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() {
            CustomizeCell = OnCustomizeCell,
        });
    }
    void OnCustomizeCell(TreeListDocumentExportCustomizeCellEventArgs args) {
        if (args.AreaType == DocumentExportAreaType.Header) {
            args.ElementStyle.TextAlignment = DevExpress.XtraPrinting.TextAlignment.MiddleCenter;
            args.ElementStyle.Font = new DXFont("Arial", 10, DXFontStyle.Bold);
        }
        if (args.AreaType == DocumentExportAreaType.DataArea) {
            var spaceObject = (SpaceObject)args.DataItem;
            if (spaceObject.TypeOfObject == "Planet")
            args.ElementStyle.BackColor = System.Drawing.Color.LightBlue;
            if (args.ColumnFieldName == "Mass10pow21kg" && (double)args.Value > 10)
                args.ElementStyle.Font = new DXFont(args.ElementStyle.Font, DXFontStyle.Bold);
        }
        if (args.AreaType == DocumentExportAreaType.TotalFooter && args.ColumnFieldName == "MeanRadiusInKM") {
            args.Text = args.SummaryItems[0].Text + " km\n" + args.SummaryItems[1].Text + "km";
            args.ElementStyle.TextAlignment = DevExpress.XtraPrinting.TextAlignment.MiddleRight;
        }
        args.Handled = true;
    }
}

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>();