Input decimal value in textbox in vb.net

Input decimal value in textbox in vb.net

Private previousText As String

    Sub New()

        ' This call is required by the designer.

        InitializeComponent()

        ' Add any initialization after the InitializeComponent() call.

        previousText = TextBox1.Text

    End Sub

    Private Sub TextBox1_TextChanged(sender As System.Object, e As System.EventArgs) Handles TextBox1.TextChanged

        If String.IsNullOrEmpty(DirectCast(sender, TextBox).Text) Then

            previousText = ""

        Else

            Dim num As Double = 0

            Dim success As Boolean = Double.TryParse(DirectCast(sender, TextBox).Text, num)

            If success And num >= 0 Then

                DirectCast(sender, TextBox).Text.Trim()

                previousText = DirectCast(sender, TextBox).Text

            Else

                DirectCast(sender, TextBox).Text = previousText

                DirectCast(sender, TextBox).SelectionStart = DirectCast(sender, TextBox).Text.Length

            End If

        End If

    End Sub