How to Save Data to File and Read Data Back from File

Imports System.IO

Public Class Form1
    Dim a As StreamReader
    Dim b As String
    Dim c As String = "C:\Program Files (x86)\temp\hungvb.txt"
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        If Not File.Exists(c) Then
            Dim d As FileStream
            d = File.Create(c)
            d.Close()
        End If

        'read file
        Try
            ComboBox1.Items.Clear()
            a = File.OpenText(c)
            While a.Peek <> -1
                b = a.ReadLine()
                ComboBox1.Items.Add(b)
            End While
            a.Close()
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try

    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If TextBox1.Text = Nothing Then
            '  Me.Text = "Enter A Password To Be Saved"
        Else
            File.AppendAllText(c, TextBox1.Text & vbCrLf)
            TextBox1.Text = ""
            '  MsgBox("Saved Pass")
            ReadFile()
        End If
    End Sub

    Private Sub ReadFile()
        Try
            ComboBox1.Items.Clear()
            a = File.OpenText(c)
            While a.Peek <> -1
                b = a.ReadLine()
                ComboBox1.Items.Add(b)
            End While
            a.Close()
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Sub
End Class