Question

I’m getting the error “A switch expression or case label must be a bool, char, string, integral, enum, or corresponding nullable type” in my code at the line,

switch (job_selecter.SelectedValue)

Here’s my code:

    private void start()
    {
        switch (job_selecter.SelectedValue)
        {
            case 0:
                head_seal_label.Text = "Ravager's Seal: Head (8)";
                break;
        }
    }

Could anyone tell me why this is happening and how I can fix it? Thanks!

Answer 1

It seems like what you really want to do is this:

switch(job_selecter.SelectedIndex)
{
    case 0:
        // do whatever
        break;

    default:
        // handle default case
        break;
}

You’ve noted in one of your responses that casting SelectedValue to string or int or whatever can cause a null reference exception if you then use it in a switch–which makes perfect sense, because it’s perfectly legal for a combo box to have nothing selected, and you’re going to need to account for that case. If you switch on SelectedIndex, handling -1 will allow you to handle a case of “no selection” specifically.

Of course, it’s worth pointing out that switching on SelectedIndex only makes sense if the combo box contains a known, unchanging set of values. Adding or removing values will potentially cause the indices of everything in the box to change, thus breaking the switch.