Dataset null reference exception

Question

I have a very simple page that retrieves records from the database and displays them on the page. In the code behind page, the records are retrieved successfully, but in the index.cshtml, it is raising a null reference exception error. Any idea why?

Answer 1

Hi @Eddy Wu

The null reference exception relates the above code, in the OnGet method, you create a new DataSet instance and set the data for it, without setting the data for the MenuItems property of PageModel. So, in the view page, it will show the null reference exception.

To solve this issue, change your code as below:

    public class IndexModel : PageModel
    {
        private readonly ILogger<IndexModel> _logger;
           
        public IndexModel(ILogger<IndexModel> logger)
        {
            _logger = logger;
        }
        public DataSet MenuItems { get; set; }
        public void OnGet()
        {
              ... // in the using statement.
               MenuItems = new DataSet();
               sda.Fill(MenuItems);
              ...
        }
    }

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Best regards,

Dillion