blazor-devexpress-dot-blazor-a7d0bdcf.md
Contains information about a DxGrid‘s layout.
Namespace : DevExpress.Blazor
Assembly : DevExpress.Blazor.v25.2.dll
NuGet Package : DevExpress.Blazor
public class GridPersistentLayout :
GridPersistentLayoutBase,
IEquatable<GridPersistentLayout>
The following members return GridPersistentLayout objects:
The Grid allows you to save and restore its layout settings that a user can change in the UI. A saved layout object includes the following data:
| Saved information | Grid parameter | GridPersistentLayout’s property |
|---|---|---|
| The current page. | DxGrid.PageIndex | Layout.PageIndex |
| The maximum number of rows displayed on a page. | DxGrid.PageSize | Layout.PageSize |
| A Boolean value that indicates whether the Grid displays all rows on one page. | DxGrid.ShowAllRows | Layout.ShowAllRows |
| Search text. | DxGrid.SearchText | Layout.SearchText |
| Filter values. | A concatenation of all Grid column filter criteria[1] with the AND operator. | Layout.FilterCriteria |
| Settings for individual columns. See the table below. | Layout.Columns.Item(i) |
Important
DevExpress components can incorrectly serialize custom enumeration values in criteria operators. Refer to the following troubleshooting topic for additional information: The XXX enumeration type is not registered for the parse operation…
The GridPersistentLayout.Columns collection stores information about column layout settings. 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, band, command, or selection. | LayoutColumn.ColumnType |
| A data field name | DxGridColumn.FieldName | LayoutColumn.FieldName |
| Group index[2] | 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 |
To save and restore the Grid layout automatically, handle the following events:
The following code snippet demonstrates how to ensure the grid’s layout persistence. When the component layout changes, the LayoutAutoSaving event handler saves the updated layout to the browser’s local storage. Once the page is reloaded or restored, the LayoutAutoLoading event handler loads the most recently-saved layout from the local storage and applies it to the grid.
@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) {
await SaveLayoutToLocalStorageAsync(e.Layout);
}
async Task<GridPersistentLayout> LoadLayoutFromLocalStorageAsync() {
try {
var json = await JSRuntime.InvokeAsync<string>("localStorage.getItem", LocalStorageKey);
return JsonSerializer.Deserialize<GridPersistentLayout>(json);
} catch {
// Mute exceptions for the server prerender stage
return null;
}
}
async Task SaveLayoutToLocalStorageAsync(GridPersistentLayout layout) {
try {
var json = JsonSerializer.Serialize(layout);
await JSRuntime.InvokeVoidAsync("localStorage.setItem", LocalStorageKey, json);
} catch {
// Mute exceptions for the server prerender stage
}
}
}
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; }
}
}
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; }
}
}
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
}
}
}
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
}
}
}
// ...
builder.Services.AddScoped<NwindDataService>();
Run Demo: Save and Restore the Layout
To prevent a specific grid setting from saving to GridPersistentLayout object, clear the corresponding option before save the grid layout. The following code snippet removes information about search text, filter, and grouping from the layout settings to be saved.
async Task Grid_LayoutAutoSaving(GridPersistentLayoutEventArgs e) {
var layout = e.Layout with {
// Prevent saving a search string text to the client layout
SearchText = null,
// Prevent saving a filter to the client layout
FilterCriteria = null,
// Prevent saving group settings to the client layout
Columns = new GridPersistentLayoutCollection<GridPersistentLayoutColumn>(
e.Layout.Columns.Select(i => i with { GroupIndex = -1 })
)
};
await SaveLayoutToLocalStorageAsync(layout);
}
To save and restore the Grid layout when necessary (for example, on a button click), call the following methods:
The following code snippet displays two buttons: Save Layout and Load Layout. When a user clicks the first button, the current Grid layout is saved to the Layout parameter. Once a user clicks the second button, the component loads the most recently-saved layout from the Layout parameter and applies it to the grid.
@using System.Text.Json
@inject NwindDataService NwindDataService
@inject IJSRuntime JSRuntime
<DxButton Text="Save Layout" Click="OnSaveClick" />
<DxButton Text="Load Layout" Click="OnLoadClick" />
<DxGrid @ref="Grid"
Data="@GridData"
AutoExpandAllGroupRows="true"
ColumnResizeMode="GridColumnResizeMode.NextColumn"
ShowGroupPanel="true"
ShowFilterRow="true"
PageSizeSelectorVisible="true"
PageSizeSelectorAllRowsItemVisible="true">
<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>
@code {
IGrid Grid { get; set; }
object GridData { get; set; }
GridPersistentLayout Layout { get; set; }
protected override async Task OnInitializedAsync() {
GridData = await NwindDataService.GetCustomersAsync();
}
void OnSaveClick() {
Layout = Grid.SaveLayout();
}
void OnLoadClick() {
Grid.LoadLayout(Layout);
}
}
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; }
}
}
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; }
}
}
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
}
}
}
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
}
}
}
// ...
builder.Services.AddScoped<NwindDataService>();
Run Demo: Save and Restore the LayoutView Example: Save and Load Layout Information
IEquatable<GridPersistentLayout>
Object DevExpress.Blazor.Grid.Internal.GridPersistentLayoutBase GridPersistentLayout
Footnotes
Filter criteria can be applied to grid data in the following ways:
The saved layout does not include information about expanded rows in groups.
See Also