Implement Drag & Drop of Custom Controls at Runtime

[arya]

Hello guys.

I am almost alien to Graphics in Vb.Net, but am pretty conversent otherwise.

I would request you to help me on the following:

• How to implement Drag & Drop of Custom Controls at Runtime?
• How to draw a line depending on two mouse-click locations on two different controls, and later curve it, depending on clicks?

P.S. I am trying to design a simulator of digital circuits, the controls would be the gates and the line, the connecting wire.

 

[Paszt]

Sounds interesting. I'm an electrical engineer myself. Seems like you have a bit of work ahead of you.

I've just been researching drag&drop myself. Here are some articles I found useful:

Implementing Drag and Drop in Visual Basic .NET @ MSDN.com
Enable Your Windows Forms Applications to Drag-and-Drop Data Objects
Implementing Drag and Drop in Windows Forms

As far as drawing the lines, look at the System.Drawing.Graphics class. The GDI+ forum here will also have many posts regarding that.

 

[tyonuts]

if you just want to move your controls, try the following:

'Declare the following:
Private Declare Function ReleaseCapture lib "user32"() as Integer

Private Declare Function SendMessage lib "user32" (hWnd as Integer, Msg as Integer, wParam as Integer, lParam as integer) as integer

Private Const WM_NCLBUTTONDOWN as Short=&HA1S


'and in the MouseMOve code of the control u want to move write this:

ReleaseCapture()
SendMessage(ctrl.Handle.ToInt32,WM_NCLBUTTONDOWN, 2, 0&)

'where ctrl is the name of your control.