Query parameters allow passing data through the URL — like /search?term=blazor&page=2. Blazor supports reading query parameters directly as component parameters.

Reading Query Parameters

@page "/search"

<h1>Search: @Term</h1>

@code {
    [Parameter, SupplyParameterFromQuery]
    public string? Term { get; set; }

    [Parameter, SupplyParameterFromQuery(Name = "page")]
    public int Page { get; set; } = 1;
}

Building URLs with Query Strings

@inject NavigationManager Nav

private void Search(string term)
{
    var uri = Nav.GetUriWithQueryParameters(
        Nav.Uri,
        new Dictionary<string, object?> {
            ["term"] = term,
            ["page"] = 1
        });
    Nav.NavigateTo(uri);
}

Best Practices

• Use query params for shareable bookmarkable state: search terms, filters, pagination
• Use component state or AppState for transient UI state that should not persist in the URL

Reference:

Wikipedia: Query String

https://en.wikipedia.org/wiki/Query_string