Thread: Draw a connection !!!

Hi forum!

I have a problem with my project. (attached file).
When I click on the "computer", I get a computer on the screen. Suppose on the screen, i have 2 computers. (they can be moved)

Now I want that:

1. When I click on the "Connection" button and choose the 2 computers, the connection is drawing. If still want to draw a connection, I have to click on the "Connection", choose the 2 computers again.

2. When I move the computer's location, "connection" will not be lost.

Thanks for reading.

And so sorry for my bad english.

https://www.box.com/s/13024643f9e569ccc28c

I downloaded the project and here is the only really relevant code:

#Region "IMPORTS"

Imports System

Imports System.Collections.Generic

Imports System.ComponentModel

Imports System.Drawing

Imports System.Text

Imports System.Windows.Forms

Imports System.Drawing.Drawing2D

Imports System.Drawing.Imaging

Imports System.Net

Imports System.IO

#End Region



Public Module Module1

    Public icom As Integer = 1

End Module



Public Class Form1

    Dim butcom(20) As Button

    Dim vtricom(20) As Point

  

    '==========================================================

#Region "BUTTONS"



    Private Sub выход_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        End

    End Sub



#End Region



    '============================================================



#Region "MOVE GROUP(i)"



    '========== DI CHUYEN Group(i)========== MOT KIEU HAM

    Private dragging As Boolean

    Private beginX, beginY As Integer



    Private Sub Control_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)

        dragging = True

        beginX = e.X

        beginY = e.Y

    End Sub



    Private Sub Control_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)

        Dim DraggedControl As Control = DirectCast(sender, Control)

        If dragging = True Then

            DraggedControl.Location = New Point(DraggedControl.Location.X +

            e.X - beginX, DraggedControl.Location.Y +

            e.Y - beginY)

            Me.Refresh()

        End If

    End Sub



    Private Sub Control_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)

        dragging = False

    End Sub



    Private Sub Control_layvitri(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)

        Dim vtriControl As New Point

        vtriControl = e.Location

    End Sub



#End Region

    '=========HET phan di chuyen group(i) ==============



#Region " TAO GROUP"



    ' "GROUP COMPUTER"

    Private Sub computer_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles computer.Click

        butcom(icom) = New Button

        With butcom(icom)

            .Name = "computer " & icom

            .Location = New Point(376, 178)

            .Width = 55

            .Height = 55

            .BackColor = Color.Green

            .Image = Image.FromFile(Application.StartupPath & "\data\PC.png")

        End With

        Me.Controls.Add(butcom(icom))

        butcom(icom).BringToFront()

        ToolTip1.SetToolTip(butcom(icom), "Computer " & icom)

        AddHandler butcom(icom).MouseDown, AddressOf Me.Control_MouseDown

        AddHandler butcom(icom).MouseDown, AddressOf Me.Control_layvitri

        AddHandler butcom(icom).MouseMove, AddressOf Me.Control_MouseMove

        AddHandler butcom(icom).MouseUp, AddressOf Me.Control_MouseUp

        icom = icom + 1

    End Sub

    '================= HET GROUP COMPUTER====================

#End Region

   

End Class

I am also curious if anyone has an elegant solution. I have started a similar project but opted for the GDI+ approach; I created a user control that keeps a collection of objects (computers in your case). The user control intercepts its parent's paint event and paints the objects stored in the collection. I am looking in to implementing an A* (pronounced A-Star) path finding algorithm to enable "connections" to be redrawn when the objects are moved by the user after a connection has been made.

One thing to note is that if you want to continue using dynamically created controls as you are, you should probably make the picturebox a panel and add the "computer" objects to the panel's control collection instead of the form's.