Unable to cast object of type 'System.String' to type 'System.IO.FileInfo'.

Hey everyone,

Code:

---

        Using SW As New IO.StreamWriter(My.Application.Info.DirectoryPath & "\mods.cfg", True)
            For Each itm As FileInfo In Me.ListBox2.Items  <--- error points to this line
                SW.WriteLine(itm)
            Next

---

Using that code, i get the exception: Unable to cast object of type 'System.String' to type 'System.IO.FileInfo'.

The idea behind the code is swapping items between two text boxes, this bit is called to update a text file which stores the remaining items after an item is deleted from the list.
This code works fine if i start with a blank list, i can add and remove items from the list with no problems.
If i exit the program and reload with items stored in the second list, and i remove from the list i get that problem, but only if theres more than 1 item in the list. If its just the 1 item it works fine.

The code im using to add to the list is almost the same,

Code:

---

For Each itm As FileInfo In Me.ListBox2.Items
            If itm.Name = ListBox1.Text Then
                MsgBox("Already Active!", , "title")
                Exit Sub
            End If
        Next

        ListBox2.Items.Add(ListBox1.SelectedItem)

        Using SW As New IO.StreamWriter(My.Application.Info.DirectoryPath & "\mods.cfg", True)

            SW.WriteLine(ListBox1.Text)

        End Using

---

And i can add fine using the code, so i'm stumped as to where i've gone wrong.

Thanks for any help in advance!

Quote:

---

The idea behind the code is swapping items between two text boxes

---

Doesnt let me edit yet, meant to say listboxes

Code:

---

Using SW As New IO.StreamWriter(My.Application.Info.DirectoryPath & "\mods.cfg", True)
            For Each itm As string In Me.ListBox2.Items                 
                    SW.WriteLine(itm)
            Next
SW.dispose()

---

Change FileInfo to string in your other procedure too..

Items in a listbox aren't of type FileInfo.

You must have added Strings in ListBox2, not FileInfo objects.

Thanks for the replies!

Quote:

---

Originally Posted by elielCT

Change FileInfo to string in your other procedure too..

Items in a listbox aren't of type FileInfo.

---

Using that i get "Conversion from type 'FileInfo' to type 'String' is not valid."

Quote:

---

You must have added Strings in ListBox2, not FileInfo objects.

---

How would i force that?
Im inputting to list box 2 from a text file using:

Code:

---

      ListBox2.Items.Clear()
        FileOpen(1, My.Application.Info.DirectoryPath & "\mods.cfg", OpenMode.Input)



        Do While Not EOF(1)
            Input(1, ModName)
            ListBox2.Items.Add(ModName)
        Loop

        FileClose(1)

---

the method you're using in your first post is vb6 legacy code. there are better ways to load your listbox:

vb.net Code:

ListBox2.Items.addrange(io.file.readalllines(My.Application.Info.DirectoryPath & "\mods.cfg"))

to rewrite your file:

vb.net Code:

Using SW As New IO.StreamWriter(My.Application.Info.DirectoryPath & "\mods.cfg", True)
   For Each itm As String In Me.ListBox2.Items
       SW.WriteLine(itm)
   Next
End Using

Thanks, the help is much appreciated!

This is my complete(ish) code

Code:

---

    Private Sub Form1_Shown(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Shown
        'refreshes list from file
        ListBox2.Items.Clear()


        ListBox2.Items.AddRange(IO.File.ReadAllLines(My.Application.Info.DirectoryPath & "\mods.cfg"))

        ListBox1.Items.Clear()

        Dim ModDir As New IO.DirectoryInfo(My.Application.Info.DirectoryPath)
        For Each myfile As IO.FileInfo In ModDir.GetFiles("*.mod", IO.SearchOption.TopDirectoryOnly)
            ListBox1.Items.Add(myfile)
        Next

    End Sub

    Private Sub cmd_Add_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmd_Add.Click

          For Each itm As String In Me.ListBox2.Items  ****ERRORS HERE*****
          If itm = ListBox1.Text Then
              MsgBox("Already Active!", , "Mod Manager")
            Exit Sub
          End If
        Next

        ListBox2.Items.Add(ListBox1.SelectedItem)

        Using SW As New IO.StreamWriter(My.Application.Info.DirectoryPath & "\mods.cfg", True)

            SW.WriteLine(ListBox1.Text)

        End Using
    End Sub



    Private Sub cmd_Remove_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmd_Remove.Click

        ListBox2.Items.Remove(ListBox2.SelectedItem)

        Using SW As New IO.StreamWriter(My.Application.Info.DirectoryPath & "\mods.cfg", True)
            For Each itm As String In Me.ListBox2.Items  ***ERRORS HERE****
                SW.WriteLine(itm)
            Next
            SW.Dispose()

        End Using

    End Sub

---

Now i have "Conversion from type 'FileInfo' to type 'String' is not valid." at the two places I've marked. One is when adding to the second list, and the second one is when removing an item from the list.
I guess the items are being added to the listbox as fileinfo types or something, im not sure :(

Ok i've narrowed it down to

- Remove function will work perfectly if used first
- As soon as i click add to list, it will add the item i've selected, but first time only
- Any subsequent used of either add or remove will result in a crash.

ListBox2.Items.Add(ListBox1.SelectedItem)

ListBox2, until that point, contains strings. ListBox1 contains IO.FileInfos.

Ahh ok! You can tell the last time i did VB it was in vb6..

Code:

---

  For Each myfile As IO.FileInfo In ModDir.GetFiles("*.mod", IO.SearchOption.TopDirectoryOnly)

---

I think thats the guilty line for making listbox1 fileinfo?

If so, how would i go about changing that to strings?

instead of this:

vb.net Code:

Dim ModDir As New IO.DirectoryInfo(My.Application.Info.DirectoryPath)
For Each myfile As IO.FileInfo In ModDir.GetFiles("*.mod", IO.SearchOption.TopDirectoryOnly)
    ListBox1.Items.Add(myfile)
Next

you can use this to display full filepaths:

vb.net Code:

ListBox1.Items.AddRange(IO.Directory.GetFiles(My.Application.Info.DirectoryPath, "*.mod"))

or this for filenames with extensions:

vb.net Code:

ListBox1.Items.AddRange(IO.Directory.GetFiles(My.Application.Info.DirectoryPath, "*.mod").Select(Function(s) IO.Path.GetFileName(s)).ToArray)

or this for filenames without extensions:

vb.net Code:

ListBox1.Items.AddRange(IO.Directory.GetFiles(My.Application.Info.DirectoryPath, "*.mod").Select(Function(s) IO.Path.GetFileNameWithoutExtension(s)).ToArray)

You, Sir, are a God!

The second one worked a charm, i massively appreciate the help :)

Glad it got resolved!