need help with FileStream for writing text

[Keylan]

I am new to using FileStream, it was introduced to me by a member here, dunfiddlin, when I had an issue with a project for a friend.

I am now trying to expand my horizon more with a little program for myself, and trying to figure out the best way to edit a specific area within a file (in this case it is a file I am calling names.db but it is not an actual database file).

I am trying to have it so that it can write a name that someone puts in a TextBox to a certain offset of the .db file. I know how to do this with 8 bit and 16 bit integers, but I cannot figure out how to do this with text. Here is the code that I got the last time I received help on Filestream:

Private Sub WriteFile()
 
        Dim writer As New IO.FileStream(filepath, IO.FileMode.OpenOrCreate, IO.FileAccess.Write)
 
        Try
            writer.Position = 6244
            writer.WriteByte(CType(TextBox1.Text, Byte)) ' insert 8 bit value
            writer.Position = 6286
            Dim b() As Byte = BitConverter.GetBytes(CType(TextBox8.Text, Int16)).ToArray
            writer.WriteByte(b(1))
            writer.Position = 6287
            writer.WriteByte(b(0))
 
        Catch ex As Exception
            MsgBox(ex.Message)
        Finally
            writer.Close()
            writer.Dispose()
        End Try
 
    End Sub

Does anyone know how to change what I have here to work with text?

I already figured out how to have it read and program the length of the names, just not how to write the names themselves. I thought maybe trying to convert it all to HEX, but I don't quite understand most of what I am finding. I found examples, but they use so many variables and extra numbers that I am not sure what to change.

I have also heard of streamwriter, but I am not sure if this would be compatible with filestream for writing the other parts.

Thank you for your time.

[billboy]

Not sure exactly what your looking for

but the file stream write has a writeline function

writer.writeline("This is a test")


hope that helps

[Keylan]

I have tried that, but it gives me an error saying "writer.writeline is not a member of System.IO.FileStream"

[dunfiddlin]

No it isn't. You wouldn't normally use FileStream for text but it's actually not that difficult.

Dim writer As New IO.FileStream(filename, IO.FileMode.OpenOrCreate, IO.FileAccess.Write)
        Dim s As String = "Name Surname" ' for example
        Dim b(s.Length - 1) As Byte
        For i = 0 To b.Length - 1
            b(i) = BitConverter.GetBytes(s(i))(0) ' it will always be one byte for a character
        Next
        writer.Write(b, offset, b.Length) ' bytearray, position, length
        writer.Close()

[billboy]

Private Sub WriteFile()
        Dim fs as New FileStream(filename,FileMode.Create,FileAccess.Write)
        Dim writer As New StreamWriter(fs)
        writer.WriteLine("SomeText")
        writer.close()
End Sub

[Keylan]

No it isn't. You wouldn't normally use FileStream for text but it's actually not that difficult.

Dim writer As New IO.FileStream(filename, IO.FileMode.OpenOrCreate, IO.FileAccess.Write)
        Dim s As String = "Name Surname" ' for example
        Dim b(s.Length - 1) As Byte
        For i = 0 To b.Length - 1
            b(i) = BitConverter.GetBytes(s(i))(0) ' it will always be one byte for a character
        Next
        writer.Write(b, offset, b.Length) ' bytearray, position, length
        writer.Close()

Thanks for helping me out again, but I am a little confused about what to change to what. I thought I knew what to do. Here is the code.

Dim f(TextBox2.Text.Length - 1) As Byte
            For i = 0 To f.Length - 1
                f(i) = BitConverter.GetBytes(TextBox2.Text(i))(0)
            Next
            writer.Write(f, 20, f.Length)

I have a textbox and tried switching what I thought would be correct, but I obviously missed something. I already used b in one of my int16s, so I used f instead. I wasn't sure what to switch the s to, so I tried TextBox2.Text.

[Keylan]

Private Sub WriteFile()
        Dim fs as New FileStream(filename,FileMode.Create,FileAccess.Write)
        Dim writer As New StreamWriter(fs)
        writer.WriteLine("SomeText")
        writer.close()
End Sub

I tried that with my current setup, but having another Dim writer is giving me errors before letting me test. It won't accept FileStream or StreamWriter without errors.

[billboy]

you shouldnt have another Dim writer, just one

post your code

[Keylan]

Private Sub WriteFile()
 
        Dim writer As New IO.FileStream(filepath, IO.FileMode.OpenOrCreate, IO.FileAccess.Write)
 
        Try
            writer.Position = 10     'dec location of sex 01 male 02 female
            writer.WriteByte(CType(TextBox3.Text, Byte))    ' insert 8 bit value
            writer.Position = 12     'dec location of age
            writer.WriteByte(CType(TextBox4.Text, Byte))    ' insert 8 bit value
        Catch ex As Exception
            'This is where I need the name to go at dec 20.  I have now fields after this, but I don't want to make the code to long for a sample. 
            MsgBox(ex.Message)
        Finally
            writer.Close()
            writer.Dispose()
        End Try
 
    End Sub

There is a small section of my writefile.