Handling 404 error in razor pages project

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In this video we will discuss handling 404 errors in an asp.net core razor pages project.

Consider the following OnGet() action. 

public IActionResult OnGet(int id)
{
    Employee = employeeRepository.GetEmployee(id);

    if(Employee == null)
    {
        return RedirectToPage("/NotFound");
    }

    return Page();
}

• If the employee with the specified ID is not found, the request is redirected to NotFound razor page using RedirectToPage() method.
• OnGet() method return type is IActionResult, where as RedirectToPage() method returns RedirectToPageResult. This is OK because RedirectToPageResult implements IActionResult.
• If the employee with the specified ID is found we want to re-render the same page. This is done by the Page() method. Page() method returns PageResult which also implements IActionResult interface.
• Changing the return type of OnGet() action from void to IActionResult allows us to return different result types that implement IActionResult interface.

NotFound razor page

@page

@{

    ViewData["Title"] = "NotFound";

}

<h1>The resource you are looking for cannot be found</h1>

<a asp-page="/Employees/Index" class="btn btn-primary">

    Click here to go back to Home

</a>