DxGridColumn.VisibleIndexChanged Event

Fires when the column’s visible index changes.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v23.2.dll

NuGet Package: DevExpress.Blazor

Declaration

[Parameter]
public EventCallback<int> VisibleIndexChanged { get; set; }

Parameters

Type	Description
Int32	A new value of the VisibleIndex property.

Remarks

The VisibleIndex property allows you to define display order for Grid columns explicitly. Users can then reorder columns at runtime. Handle the VisibleIndexChanged event to respond to column position changes.

Razor

@inject WeatherForecastService ForecastService

<DxGrid Data="@Data">
    <Columns>
        <DxGridDataColumn FieldName="Date" DisplayFormat="D" VisibleIndex="@CurrentIndex"
                          VisibleIndexChanged="OnVisibleIndexChanged" />
        <DxGridDataColumn FieldName="TemperatureC" Caption="@("Temp. (\x2103)")" Width="120px" />
        <DxGridDataColumn FieldName="TemperatureF" Caption="@("Temp. (\x2109)")" Width="120px" />
        <DxGridDataColumn FieldName="Forecast" />
        <DxGridDataColumn FieldName="CloudCover" />
    </Columns>
</DxGrid>

<div>@IndexInfo</div>

@code {
    object Data { get; set; }
    int CurrentIndex { get; set; }
    string IndexInfo { get; set; }

    protected override void OnInitialized() {
        Data = ForecastService.GetForecast();
    }

    void OnVisibleIndexChanged(int newIndex) {
        CurrentIndex = newIndex;
        IndexInfo = "You moved the 'Date' column to position " + (newIndex + 1);
    }
}

WeatherForecast

using System;

public class WeatherForecast {
    public DateTime Date { get; set; }
    public int TemperatureC { get; set; }
    public double TemperatureF => Math.Round((TemperatureC * 1.8 + 32), 2);
    public string Forecast { get; set; }
    public string CloudCover { get; set; }
    public bool Precipitation { get; set; }
}

WeatherForecastService

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, 15).Select(index => {
            var temperatureC = rng.Next(-10, 30);
            return new WeatherForecast {
                Date = startDate.AddDays(index),               
                TemperatureC = temperatureC,
                CloudCover = CloudCover[rng.Next(0, 4)],
                Precipitation = Convert.ToBoolean(rng.Next(0, 2)),
                Forecast = ConditionsForForecast.First(c => c.Item1 <= temperatureC).Item2
            };
        }).ToList();
    }

    public IEnumerable<WeatherForecast> GetForecast() {
        return Forecast.ToArray();
    }
    // ...
}

Program.cs

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

Set DxGrid.AllowColumnReorder or DxGridColumn.AllowReorder property to false to prevent users from reordering columns.