How to open a .txt file and display it in a text box using VB.Net

Imports System.IO

Public Class MyForm

    ' ... Whatever code you have for your form

    Public Sub OpenFile()

        Dim oReader As StreamReader

        OpenFileDialog1.CheckFileExists = True
        OpenFileDialog1.CheckPathExists = True
        OpenFileDialog1.DefaultExt = "txt"
        OpenFileDialog1.FileName = ""
        OpenFileDialog1.Filter = "Text Files (*.txt)|*.txt|All Files (*.*)|*.*"
        OpenFileDialog1.Multiselect = False

        If OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.OK Then
            oReader = New StreamReader(OpenFileDialog1.FileName, True)
            RichTextBox1.Text = oReader.ReadToEnd
        End If

    End Sub

End Class