public async Task <IActionResult> OnGetAsync(string categoryName, int pageNumber)
{
var productList = await _catalogApi.GetCatalog();
CategoryList = productList.Select(p => p.Category).Distinct();
if (!string.IsNullOrWhiteSpace(categoryName))
{
ProductList = productList.Where(p => p.Category == categoryName);
SelectedCategory = categoryName;
}
else if (pageNumber > 0)
{
ProductList = await _catalogApi.GetProductByPage(pageNumber);
}
else
{
ProductList = productList;
}
return(Page());
}