How to change filepath when check a radiobutton? Visual basic

My problem here is that i have 3 radiobuttons for 3 different categories: Huse Folii and Altele.

The idea is when i select a radiobutton,the filepath will change to Huse,Folii or Altele.

For example i tried to make _path :

Dim _path As String = IO.Path.Combine("C:\Descriere\Huse\")

then use the _path here:

Dim ioFile As New System.IO.StreamReader(_path + "a.txt")

but it didn't worked,for sure i do something wrong,but i can't find how or where to use that _path...

Here is the code: Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click On Error Resume Next TextBox1.Clear() If RadioButton1.Checked = True Then Dim _path As String = IO.Path.Combine("C:\Descriere\Huse\") End If If RadioButton2.Checked = True Then Dim _path As String = IO.Path.Combine("C:\Descriere\Folii\") End If If RadioButton3.Checked = True Then IO.Path. Dim _path As String = IO.Path.Combine("C:\Descriere\Altele\") End If

        Dim ioFile As New System.IO.StreamReader(_path + "a.txt")
        Dim lines As New List(Of String)
        Dim rnd As New Random()
        Dim line As Integer
        While ioFile.Peek <> -1
            lines.Add(ioFile.ReadLine())
        End While
        line = rnd.Next(lines.Count + 1)
        TextBox1.AppendText(lines(line).Trim())
        ioFile.Close()
        ioFile.Dispose()
        Dim ioFile2 As New System.IO.StreamReader(path:=+"core.txt")
        Dim lines2 As New List(Of String)
        Dim rnd2 As New Random()
        Dim line2 As Integer
        While ioFile2.Peek <> -1
            lines2.Add(ioFile2.ReadLine())
        End While
        line2 = rnd2.Next(lines2.Count + 1)
        TextBox1.AppendText(lines2(line2).Trim())
        ioFile2.Close()
        ioFile2.Dispose()
        Dim ioFile3 As New System.IO.StreamReader(path:=+"x.txt")
        Dim lines3 As New List(Of String)
        Dim rnd3 As New Random()
        Dim line3 As Integer
        While ioFile3.Peek <> -1
            lines3.Add(ioFile3.ReadLine())
        End While
        line3 = rnd3.Next(lines3.Count + 1)
        TextBox1.AppendText(lines3(line3).Trim())
        ioFile3.Close()
        ioFile3.Dispose()
        TextBox1.Text = Replace(TextBox1.Text, "BRAND", TextBox2.Text)
        TextBox1.Text = Replace(TextBox1.Text, "MODEL", TextBox3.Text)
        Dim count As Integer = 0
        count = TextBox1.Text.Split(" ").Length - 1
        Label5.Text = "Caractere:" & Len(TextBox1.Text)
    End Sub