My.Settings save Combobox Items?

Hello! I have been working on code and wanna store Combo Box items in Application settings since that seems easiest. I have made the variable I made in the settings(comiclist) as Strings Collection basically. Anyways, when the user first loads the application, I have a form that comes up and allows the user to input values to populate the combobox. The code I have for them saving the values first is:

Code:

---

    Private Sub txtData_KeyDown(sender As Object, e As KeyEventArgs) Handles txtData.KeyDown
        If (e.KeyCode = Keys.Enter) Then
            My.Settings.ComicList.Add(txtdata.Text)
        End If
    End Sub

---

But the error I get is 'Object reference not set to an instance of an object.'
I figured to add the .ToString() at the end of My.Settings.ComicList.Add(txtdata.Text) but nah, that didn't work. This is the first time I've worked with String Collection so anything I am doing wrong?

My.Settings is one of those things I gave up on a long time ago because I was already used to maintaining my own settings files and I kept having to spend time on little warts that didn't make any sense.

In this case: if you don't pre-populate a StringCollection setting with any values, it has no values. As far as My.Settings is concerned, "no values" means it shouldn't bother making a StringCollection instance, which means it's Nothing by default.

So to be safe, your application should expect this and protect itself:

Code:

---

Protected Overrides Sub OnShown(e As EventArgs)
    MyBase.OnShown(e)

    If My.Settings.TestSetting Is Nothing Then
        My.Settings.TestSetting = New Specialized.StringCollection()
        My.Settings.Save()
    End If
End Sub

---

That's not the only way to do it, but it's a good way to make sure at startup the collection exists.

Alright, thank you man! May I ask, how did you do that Protected Overrides?

I know that Shown is an event forms implement. The pattern Microsoft follows is that for every event, there is a Protected Overridable On<EventName>() method you can override instead of messing with setting up an event handler on yourself. So I typed "Overrides OnShown" and Intellisense filled in the rest for me.

Oh. That is interesting. Thank you for the help! It all works good now for that issue. Thanks again mate, have a good day!