Set "All" PageSize Option as Default

Environment

Product	Grid for Blazor
Version	5.1.1 or earlier

Description

I want to set the default selected entry in the Pager of the Telerik Grid to be "All" items. However, the PageSize property only accepts a non-nullable int, so I cannot bind it to a nullable int? variable. Is there a way to initialize the PageSize with null to indicate that I want the "All" option as the default?

Solution

The PageSize parameter of the Grid accepts a non-nullable int by design. To set the "All" option as the default for the page size in the Telerik Grid, use a custom approach as follows:

1. In the component's initialization method (OnInitializedAsync), load the data and set the PageSize property to the total count of the records.
2. Add the "All" option (null) to the PageSizes collection.
3. Bind the PageSize property to the @bind-PageSize attribute of the TelerikGrid component.
4. Specify the PageSizes collection in the GridPagerSettings component to display the dropdown with the available page sizes.

Starting with Telerik UI for Blazor 6.0.0, the above approach causes the pager DropDownList tо display the actual item count. The "All" item for the DropDownList shows only when the user selects it manually.

Set "All" PageSize Option as Default

Page size: @PageSize

<TelerikGrid Data="@GridData"
             Pageable="true"
             @bind-PageSize="@PageSize"
             Height="500px">
    <GridSettings>
        <GridPagerSettings InputType="PagerInputType.Buttons"
                           PageSizes="@PageSizes" 
                           ButtonCount="5">
        </GridPagerSettings>
    </GridSettings>
    <GridColumns>
        <GridColumn Field="@(nameof(Product.Name))" Title="Product Name" />
        <GridColumn Field="@(nameof(Product.Price))" />
        <GridColumn Field="@(nameof(Product.Released))" />
        <GridColumn Field="@(nameof(Product.Discontinued))" />
    </GridColumns>
</TelerikGrid>

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

    private int PageSize { get; set; }

    private List<int?> PageSizes { get; set; } = new List<int?> { null, 5, 10, 15 };

    protected override async Task OnInitializedAsync()
    {
        await LoadData();

        PageSize = GridData.Count();
    }

    private async Task LoadData()
    {
        GridData = Enumerable.Range(1, 30).Select(x => new Product
            {
                Id = x,
                Name = "Product name " + x,
                Price = (decimal)(x * 3.14),
                Released = DateTime.Now.AddMonths(-x).Date,
                Discontinued = x % 5 == 0
            }).ToList();
    }

    public class Product
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public decimal Price { get; set; }
        public DateTime Released { get; set; }
        public bool Discontinued { get; set; }
    }
}