Variable 'fs' hides variable in an enclosing block

Question

I am currently using the following code:

    Public Sub CreateScore()
    ' open isolated storage, and write the savefile.
    Dim fs As IsolatedStorageFileStream = Nothing
    Using fs = savegameStorage.CreateFile("Score")
    If fs IsNot Nothing Then

        ' just overwrite the existing info for this example.
        Dim bytes As Byte() = System.BitConverter.GetBytes(Scorecount)
        fs.Write(bytes, 0, bytes.Length)
    End If

    End Using

End Sub

However the fs after using is underlined in blue and gives the error Variable 'fs' hides variable in an enclosing block.

Does anybody know how i can fix this?

Solution 1

You are declaring the variable, then using that same variable name in a Using block (which tries to declare it again).

Change it to this:

Public Sub CreateScore()
    ' open isolated storage, and write the savefile.
    Using fs As IsolateStorageFileStream = savegameStorage.CreateFile("Score")
    If fs IsNot Nothing Then

        ' just overwrite the existing info for this example.
        Dim bytes As Byte() = System.BitConverter.GetBytes(Scorecount)
        fs.Write(bytes, 0, bytes.Length)
    End If

    End Using

 End Sub

Solution 2

You don't need the Dim fs... line - the Using statement covers the declaration.

The Using statement on its own should be fine as you have it, but if you want to be sure of the typing then change it to:

Using fs As IsolatedStorageFileStream = savegameStorage.CreateFile("Score")
...

Comments

[Ňɏssa Pøngjǣrdenlarp]

try Using fs As IsolatedStorageFileStream = savegameStorage.CreateFile("Score") and get rid of the DIM statement. you have 2 versions of fs there, but I am not sure that is how ISO works.

[Idle_Mind]

The Using statement will dispose of the variable when the end of its block is reached. Since you've declared it previously, however, the block can't do that. You need to declare that variable in the Using statement itself as Plutonix and Jon Egerton have shown. The fs variable will only be scoped to that Using block then, and therefore it will be safe to be automatically disposed.

[Douglas Barbin]

The Using statement may or may not be fine as he has it. It won't be if he has Option Infer Off (which I realize is probably unlikely, but we have it off at my office for whatever reason).

[Jon Egerton]

Actually, with "Option Infer Off" he's still (sort of fine): fs would end up typed as "Object", which, while a pain to code against, should still work.