Imports System.IO

Public Class Form3

    Private Sub Form3_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint

        Dim blackPen As New Pen(Color.Red, 3)

        Dim x1 As Single
        Dim y1 As Single
        Dim x2 As Single
        Dim y2 As Single

        Try
            ' Create an instance of StreamReader to read from a file.
            Using sr As StreamReader = New StreamReader("C:\coordinate.txt")
                Dim line() As String
                ' Read and display the lines from the file until the end 
                ' of the file is reached.
                Do
                    line = Split(sr.ReadLine(), ";", -1)
                   
                    x1 = line(0)
                    y1 = line(1)
                    x2 = line(2)
                    y2 = line(3)

                    e.Graphics.DrawLine(blackPen, x1, y1, x2, y2)

                Loop Until line Is Nothing

                sr.Close()

            End Using
        Catch ex As Exception
            ' Let the user know what went wrong.
            Console.WriteLine("The file could not be read:")
            Console.WriteLine(ex.Message)
        End Try


    End Sub
End Class