Radzen Blazor DataGrid Is Slow with several columns

Marwan · May 16, 2022, 10:42am

Hello, not only the first render of Radzen's Blazor DataGrid's is slow with large number of columns, its response to every action is also unnecessarily slow.
My hypothesis is that ShouldRender() method of the components hasn't been properly implemented..
.
Do you have any ideas why its so?

enchev · May 16, 2022, 10:45am

There is no such implementation at all - the source code is here and you can debug your case:

github.com

radzenhq/radzen-blazor/blob/master/Radzen.Blazor/RadzenDataGrid.razor

@using System.Linq.Dynamic.Core
@using Microsoft.JSInterop
@using Microsoft.AspNetCore.Components.Forms
@using Radzen
@typeparam TItem
@inherits PagedDataBoundComponent<TItem>

@if (Columns != null)
{
    <CascadingValue Value=this>
        @Columns
    </CascadingValue>
}

@if (Visible)
{
    var visibleColumns = columns.Where(c => c.GetVisible()).ToList();

    <div @ref=@Element style="@Style;outline:none;" @attributes="Attributes" class="rz-data-grid @GetCssClass()" id="@GetId()" @onkeydown="@OnKeyDown" @onkeydown:preventDefault tabindex=0>
        @if (AllowGrouping || AllowColumnPicking)

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There are many example with many columns and the DataGrid is not slow, even with composite columns:

Marwan · May 16, 2022, 11:04am

Thanks for your response.
But I'm surprised! how come you don't override ShouldRender() in the components. Without ShouldRender() overridden not only there is no point in V-DOM, it even makes it slower.
You should consider overriding ShouldRender() in all the components.
.
.
Best Regards

enchev · May 16, 2022, 11:39am

ShouldRender() should be overridden only in special cases like this one otherwise you might brake the component lifecycle.