@using Telerik.DataSource
@using Telerik.DataSource.Extensions

<p>Grid Page Size from parameter: <strong>@GridPageSize</strong></p>
<p>Grid Page Size from OnRead event: <strong>@GridPageSizeFromOnRead</strong></p>

<TelerikGrid OnRead="@OnGridRead"
             TItem="@Product"
             FilterMode="GridFilterMode.FilterRow"
             Pageable="true"
             @bind-PageSize="@GridPageSize"
             Sortable="true"
             Height="400px">
    <GridSettings>
        <GridPagerSettings PageSizes="@( new List<int?> { null, 10, 20, 50 } )" />
    </GridSettings>
    <GridColumns>
        <GridColumn Field="@nameof(Product.Name)" />
        <GridColumn Field="@nameof(Product.Group)" />
        <GridColumn Field="@nameof(Product.Price)" DisplayFormat="{0:c2}" />
        <GridColumn Field="@nameof(Product.Quantity)" DisplayFormat="{0:n0}" />
        <GridColumn Field="@nameof(Product.Released)" DisplayFormat="{0:d}" />
        <GridColumn Field="@nameof(Product.Discontinued)" />
    </GridColumns>
</TelerikGrid>

@code {
    private List<Product> GridData { get; set; } = new();

    private int GridPageSize { get; set; } = 10;
    private int GridPageSizeFromOnRead { get; set; }

    private async Task OnGridRead(GridReadEventArgs args)
    {
        GridPageSizeFromOnRead = args.Request.PageSize;

        DataSourceResult result = await GridData.ToDataSourceResultAsync(args.Request);

        args.Data = result.Data;
        args.Total = result.Total;
        args.AggregateResults = result.AggregateResults;
    }

    protected override void OnInitialized()
    {
        var rnd = Random.Shared;

        for (int i = 1; i <= 77; i++)
        {
            GridData.Add(new Product()
            {
                Id = i,
                Name = $"Name {i} {(char)rnd.Next(65, 91)}{(char)rnd.Next(65, 91)}",
                Group = $"Group {i % 3 + 1}",
                Price = rnd.Next(1, 100) * 1.23m,
                Quantity = rnd.Next(0, 10000),
                Released = DateTime.Today.AddDays(-rnd.Next(60, 1000)),
                Discontinued = i % 4 == 0
            });
        }
    }

    public class Product
    {
        public int Id { get; set; }
        public string Name { get; set; } = string.Empty;
        public string Group { get; set; } = string.Empty;
        public decimal Price { get; set; }
        public int Quantity { get; set; }
        public DateTime Released { get; set; }
        public bool Discontinued { get; set; }
    }
}