Text Box Border Largest Vb.Net When Empty Then Red When Fill Then Green

in this post you can learn about Text box Border Color and Size Change in VB.NET make the Text boxes then paste the below code.

 Public Class Form1
    Private Sub Form1_Paint(sender As Object, e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint

        With TextBox1
            Dim p As New Pen(If(TextBox1.Text <> "", Color.Green, Color.Red), 3)
            e.Graphics.DrawRectangle(p, .Left - 1, .Top - 1, .Width + 2, .Height + 2)
            p.Dispose()

        End With

        With TextBox2
            Dim p As New Pen(If(TextBox2.Text <> "", Color.Green, Color.Red), 3)
            e.Graphics.DrawRectangle(p, .Left - 1, .Top - 1, .Width + 2, .Height + 2)
            p.Dispose()
        End With
        With TextBox3
            Dim p As New Pen(If(TextBox3.Text <> "", Color.Green, Color.Red), 3)
            e.Graphics.DrawRectangle(p, .Left - 1, .Top - 1, .Width + 2, .Height + 2)
            p.Dispose()
        End With
    End Sub

    Private Sub TextBox1_TextChanged(sender As System.Object, e As System.EventArgs) Handles TextBox1.TextChanged, TextBox2.TextChanged
        Me.Invalidate()
    End Sub

    Private Sub TextBox2_TextChanged(sender As System.Object, e As System.EventArgs) Handles TextBox2.TextChanged
        Me.Invalidate()
    End Sub

    Private Sub TextBox3_TextChanged(sender As System.Object, e As System.EventArgs) Handles TextBox3.TextChanged
        Me.Invalidate()
    End Sub
End Class