GridDocumentExportCustomizeCellEventArgs.GroupFieldName Property

Returns the column field name of the processed group.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v25.1.dll

NuGet Package: DevExpress.Blazor

Declaration

public string GroupFieldName { get; }

Property Value

Type	Description
String	If the processed cell belongs to a group header/footer, the property returns the group field name. Otherwise, the property returns null.

Remarks

When exporting Grid data to PDF, handle the CustomizeCell event to customize table cells in the output file. The AreaType event argument identifies the area containing the processed cell.

Use the GroupFieldName argument to obtain the column field name of the processed group. The argument returns null if the cell does not belong to a group header/footer (AreaType returns a value other than GroupHeader/GroupFooter).

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>();