How to make a picturebox dragable?

Question

I am an enthusiastic programmer and new to stack overflow. I am trying to build a prototype of an OS(Operating System) in C#...Just a test.

Just like we see that we can drag things in the desktop and put it anywhere I am creating a desktop for my OS.

So how should I make an icon(a picturebox) drag-able and how would I save its position so that next time I open my desktop I see it in the same place? I would love the dragging without any freezes or those sneaky bugs. I would love if, it is as close and smooth as the ones in Windows(dragging items(icons) in desktop)..

Thanks...

wpf? winforms? perhaps web? – Zohar Peled May 19 '16 at 05:19 — Zohar Peled, May 19 '16 at 05:19

score 0 · Accepted Answer · edited May 23 '17 at 11:44

Yes, it is.

Assume a Picturebox named "pbxBigCat" (load it with a pPicture ...)

Add this lines to your form:

    public const int WM_NCLBUTTONDOWN = 0xA1;
    public const int HT_CAPTION = 0x2;

    [DllImportAttribute("user32.dll")]
    public static extern int SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);
    [DllImportAttribute("user32.dll")]
    public static extern bool ReleaseCapture();

And then write an eventhandler for the pbxBigCat MouseDown event:

    private void pbxBigCat_MouseDown(object sender, MouseEventArgs e)
    {
        if (e.Button == MouseButtons.Left)
        {
            ReleaseCapture();
            SendMessage(pbxBigCat.Handle, WM_NCLBUTTONDOWN, HT_CAPTION, 0);
        }
    }

If you test it you will se it works. For more Information (like saving positions etc.) I refere to Make a borderless form movable?

Another possibility to do this (now we have a Label called label1)

public partial class Form1 : Form
{
    private bool mouseDown;
    private Point lastLocation;

    public Form1()
    {
        InitializeComponent();
    }

    private void pbxBigCat_MouseDown(object sender, MouseEventArgs e)
    {
        if (e.Button == MouseButtons.Left)
        {
            mouseDown = true;
            lastLocation = e.Location;
        }
    }

    private void pbxBigCat_MouseMove(object sender, MouseEventArgs e)
    {
        if (mouseDown)
        {
            pbxBigCat.Location = new Point((pbxBigCat.Location.X - lastLocation.X + e.X), (pbxBigCat.Location.Y - lastLocation.Y) + e.Y);
            label1.Text = pbxBigCat.Location.X.ToString() + "/" + pbxBigCat.Location.Y.ToString();
        }
    }

    private void pbxBigCat_MouseUp(object sender, MouseEventArgs e)
    {
        mouseDown = false;
    }
}

Everything drawn from the example on the mentioned SO article.

I thought the code would work perfectly but nothing really happens and I even tried it on a form and the referral link you gave me contains no information on how to save the positions. — s1nisteR, May 19 '16 at 13:14
Then you did not read the full thread. You can use the mousemove event to get the actual positions, and then save it for your purposes. — nabuchodonossor, May 19 '16 at 13:17
And i tried it again, and it is operating. I can move around the picture. — nabuchodonossor, May 19 '16 at 13:17
Thanks bro. The alternative method is working really nicely. You are the best. Thanks a very lot. — s1nisteR, May 20 '16 at 06:04
You are welcome ... If this answer fits your needs, please ACCEPT it as answer - thats the way to say thanks! — nabuchodonossor, May 20 '16 at 08:12

How to make a picturebox dragable?

1 Answers1