GridPersistentLayoutColumn Class

Contains information about layout settings for columns.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v22.1.dll

NuGet Package: DevExpress.Blazor

Declaration

public class GridPersistentLayoutColumn :
    IEquatable<GridPersistentLayoutColumn>

Remarks

The Grid allows you to save and restore its layout settings that a user can change in the UI. A GridPersistentLayout object stores layout settings at the Grid level. The GridPersistentLayout.Columns collection stores layout settings for columns. Each collection item (a GridPersistentLayoutColumn object) includes the following data:

Saved information	Grid column parameter	GridPersistentLayoutColumn’s property
Column type	A column type defined in the markup: data, command, or selection.	LayoutColumn.ColumnType
A data field name	DxGridColumn.FieldName	LayoutColumn.FieldName
Group index[1]	DxGridColumn.GroupIndex	LayoutColumn.GroupIndex
Sort index	DxGridColumn.SortIndex	LayoutColumn.SortIndex
Sort direction	DxGridColumn.SortOrder	LayoutColumn.SortOrder
Position	DxGridColumn.VisibleIndex	LayoutColumn.VisibleIndex
Visibility	DxGridColumn.Visible	LayoutColumn.Visible
Width	DxGridColumn.Width	LayoutColumn.Width

Handle the following events to save and restore the Grid layout automatically:

• LayoutAutoSaving – Fires each time the grid’s layout changes and allows you to save the layout.
• LayoutAutoLoading – Fires once the grid component is initialized and allows you to restore the saved layout.

To save and restore the Grid layout on demand (for example, on a button click), call the following methods:

• SaveLayout() – Saves information about a Grid’s layout.
• LoadLayout(GridPersistentLayout) – Loads a layout and applies it to the Grid.

The code below excludes a column’s GroupIndex parameter from the list of saved column layout settings.

Razor

@using System.Text.Json
@inject NwindDataService NwindDataService
@inject IJSRuntime JSRuntime

@if(PreRendered) {
    <DxGrid @ref="Grid" Data="@GridData" AutoExpandAllGroupRows="true"
        ColumnResizeMode="GridColumnResizeMode.NextColumn"
        ShowGroupPanel="true" ShowFilterRow="true"
        PageSizeSelectorVisible="true" PageSizeSelectorAllRowsItemVisible="true"
        LayoutAutoLoading="Grid_LayoutAutoLoading"
        LayoutAutoSaving="Grid_LayoutAutoSaving">
        <Columns>
            <DxGridDataColumn FieldName="Country" GroupIndex="0" />
            <DxGridDataColumn FieldName="City" GroupIndex="1" />
            <DxGridDataColumn FieldName="CompanyName" />
            <DxGridDataColumn FieldName="Address" />
            <DxGridDataColumn FieldName="Phone" />
            <DxGridDataColumn FieldName="ContactName" />
        </Columns>
    </DxGrid>
} else {
    <em>Loading...</em>
}

@code {
    const string LocalStorageKey = "Grid-LayoutPersistence-Data";

    bool PreRendered { get; set; }
    IGrid Grid { get; set; }
    object GridData { get; set; }

    protected override async Task OnInitializedAsync() {
        GridData = await NwindDataService.GetCustomersAsync();
    }

    protected override void OnAfterRender(bool firstRender) {
        if(firstRender) {
            PreRendered = true;
            StateHasChanged();
        }
    }

    async Task Grid_LayoutAutoLoading(GridPersistentLayoutEventArgs e) {
        e.Layout = await LoadLayoutFromLocalStorageAsync();
    }

    async Task Grid_LayoutAutoSaving(GridPersistentLayoutEventArgs e) {
        var layout = e.Layout with {
            Columns = new GridPersistentLayoutCollection<GridPersistentLayoutColumn>(
                e.Layout.Columns.Select(i => i with { GroupIndex = null })
            )
        };
        await SaveLayoutToLocalStorageAsync(layout);
    }

    async Task<GridPersistentLayout> LoadLayoutFromLocalStorageAsync() {
        try {
            var json = await JSRuntime.InvokeAsync<string>("localStorage.getItem", LocalStorageKey);
            return JsonSerializer.Deserialize<GridPersistentLayout>(json);
        } catch {
            // Mute exceptions
            return null;
        }
    }

    async Task SaveLayoutToLocalStorageAsync(GridPersistentLayout layout) {
        try {
            var json = JsonSerializer.Serialize(layout);
            await JSRuntime.InvokeVoidAsync("localStorage.setItem", LocalStorageKey, json);
        } catch {
            // Mute exceptions
        }
    }
}

Invoice

using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;

namespace BlazorDemo.Data.Northwind {
    public class Invoice {
        public string ShipName { get; set; }
        public string ShipAddress { get; set; }
        public string ShipCity { get; set; }
        public string ShipRegion { get; set; }
        public string ShipPostalCode { get; set; }
        public string ShipCountry { get; set; }
        public string CustomerId { get; set; }
        public string CustomerName { get; set; }
        public string Address { get; set; }
        public string City { get; set; }
        public string Region { get; set; }
        public string PostalCode { get; set; }
        public string Country { get; set; }
        public string Salesperson { get; set; }
        public int OrderId { get; set; }
        public DateTime? OrderDate { get; set; }
        public DateTime? RequiredDate { get; set; }
        public DateTime? ShippedDate { get; set; }
        public string ShipperName { get; set; }
        public int ProductId { get; set; }
        public string ProductName { get; set; }
        public decimal UnitPrice { get; set; }
        public short Quantity { get; set; }
        public float Discount { get; set; }
        public decimal? ExtendedPrice { get; set; }
        public decimal? Freight { get; set; }
    }
}

Customer

using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;

namespace BlazorDemo.Data.Northwind {
    public partial class Customer {
        public Customer() {
            Orders = new HashSet<Order>();
        }

        public string CustomerId { get; set; }
        public string CompanyName { get; set; }
        public string ContactName { get; set; }
        public string ContactTitle { get; set; }
        public string Address { get; set; }
        public string City { get; set; }
        public string Region { get; set; }
        public string PostalCode { get; set; }
        public string Country { get; set; }
        public string Phone { get; set; }
        public string Fax { get; set; }

        public virtual ICollection<Order> Orders { get; set; }
    }
}

NwindDataService.Invoices

using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using BlazorDemo.Data.Northwind;
using BlazorDemo.DataProviders;

namespace BlazorDemo.Services {
    public partial class NwindDataService {
        public Task<IEnumerable<Invoice>> GetInvoicesAsync(CancellationToken ct = default) {
            // Return your data here
        }
    }
}

NwindDataService.Customers

using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using BlazorDemo.Data.Northwind;
using BlazorDemo.DataProviders;

namespace BlazorDemo.Services {
    public partial class NwindDataService {
        public Task<IEnumerable<Customer>> GetCustomersAsync(CancellationToken ct = default) {
            // Return your data here
        }
    }
}

Program.cs

// ...
builder.Services.AddScoped<NwindDataService>();

Implements

IEquatable<GridPersistentLayoutColumn>

Inheritance

Object

GridPersistentLayoutColumn

Footnotes

1. The saved layout does not include information about expanded rows in groups.