[2005] Won't edit entry!!!

Hi all,

I'm trying to create a program... (Who isn't here -.-)

Well, I want to edit an entry in my current dictionary, but it just adds it.

This is my code:

Code:

---

    Private Sub SaveData()
        SR.Close()
        Dim SW As StreamWriter

        My.Computer.FileSystem.DeleteFile("Dictionary.txt")
        SW = New StreamWriter("Dictionary.txt")
            For Counter = 0 To NumTerms
            SW.WriteLine(Term(Counter))
            SW.WriteLine(Definition(Counter))
            Next

        SW.Close()
    End Sub
    Private Sub LoadDictionary()
        NumTerms = -1
        SR = New StreamReader("Dictionary.txt")

        Do While SR.EndOfStream = False
            NumTerms += 1
            Term(NumTerms) = SR.ReadLine
            Definition(NumTerms) = SR.ReadLine
        Loop
    End Sub
    Private Sub btn_Save2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_Save2.Click
        Term(lst_results.SelectedIndex) = txt_Name.Text
        Definition(lst_results.SelectedIndex) = txt_Description.Text
        SaveData()
        LoadDictionary()
    End Sub

---

I want to delete the text file and then "re-write" it all back, then load it again. Anyone have any ideas?

vb.net Code:

My.Computer.FileSystem.DeleteFile("FilePath")
        My.Computer.FileSystem.WriteAllText("FilePath", counter & " : " & definition, True)
        My.Computer.FileSystem.ReadAllText("FilePath")

Why do this:

vb.net Code:

My.Computer.FileSystem.DeleteFile("FilePath")
My.Computer.FileSystem.WriteAllText("FilePath", counter & " : " & definition, True)

when you can just do this:

vb.net Code:

My.Computer.FileSystem.WriteAllText("FilePath", counter & " : " & definition, False)

Okay, I've tried both, and I can't get it to work.

I've got two arrays:

Term()
and
Definition()

When the dictionary loads up, it reads all the terms and definitions to those arrays using the following code:

Code:

---

Private Sub LoadDictionary()
        NumTerms = -1
        SR = New StreamReader("Dictionary.txt")

        Do While SR.EndOfStream = False
            NumTerms += 1
            Term(NumTerms) = SR.ReadLine
            Definition(NumTerms) = SR.ReadLine
        Loop
    End Sub

---

That works perfectly, however, when I go to edit an entry, you want to edit it and the editing take effect straight away usually wouldn't you?

Well, that's what I can't do...

Once the user edits an entry, I want the dictionary to re-write ALL the terms and definitions to a text file and then re-load the dictionary.

It will have to write each term the it's definition, so I think the code would look something like this:

Code:

---

Private Sub SaveData()
        SR.Close()
        My.Computer.FileSystem.DeleteFile("Dictionary.txt")
        For Counter = 0 To NumTerms
            My.Computer.FileSystem.WriteAllText("Dictionary.txt", Term(Counter), True)
            My.Computer.FileSystem.WriteAllText("Dictionary.txt", Definition(Counter), True)
        Next
    End Sub

---

But it doesn't work ... Any ideas here?
Thanks in advance.

Do you know what WriteAllText does? It opens a file, writes all the text you specify, then closes the file. Do you really want to open and close the same file twice for every entry you write to the database?

You should be writing it as you're reading it. If you're using StreamReader.ReadLine to read lines alternately from the file then it would make sense to use StreamWriter.WriteLine to write lines alternately to the file.

That said, you shouldn't be using two separate lists for the terms and definitions and you don't need that NumTerms variable either:

vb.net Code:

Dim definitionsByTerm As New Dictionary(Of String, String)
 
Using reader As New IO.StreamReader("file path here")
    While Not reader.EndOfStream
        'Add an item with the term line as the key and the definition line as the value.
        definitionsByTerm.Add(reader.ReadLine(), reader.ReadLine())
    End While
End Using
 
Using writer As New IO.StreamWriter("file path here")
    For Each item As KeyValuePair(Of String, String) In definitionsByTerm
        MessageBox.Show(item.Value, item.Key)
 
        'Write the term to the file.
        writer.WriteLine(item.Key)
 
        'Write the definition to the file.
        writer.WriteLine(item.Value)
    Next item
End Using

If you want to get or set a definition in the collection in between you just index the Dictionary by key, which means with a term, e.g.

vb.net Code:

Dim someDefinition As String = definitionsByTerm(someTerm)
 
definitionsByTerm(someOtherTerm) = someOtherDefinition