Move window without border

Question

How do I move a window that does not have a border. There is no empty space on the application, all that is available is a webbrowser and a menustrip. I would like the users to be able to move the window by dragging the menu strip. How do I code this? I have tried a few code blocks I have found online, but none of them worked.

Groundmass

Probably because it's impossible for the application (or the user) to distinguish whether a click on the MenuStrip is intended to move the application or open a menu. There's a reason that windows have borders—rethink your design. – Gaskill

Answer 1

This Code Project article should help you accomplish this. I've used this myself with no problems. This is the jist of it:

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();

private void Form1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{     
    if (e.Button == MouseButtons.Left)
    {
        ReleaseCapture();
        SendMessage(Handle, WM_NCLBUTTONDOWN, HT_CAPTION, 0);
    }
}

This will basically "trick" the window manager into thinking that it is grabbing the title bar of the winform.

To apply it to your project, just use the MouseDown event from the MenuStrip.

Daciadacie

That works really great. You can add the contents of the method in any MouseDown event, for example a picture... – Karyosome

This works even if a borderless form is run inside another c# app where the Point method fails. Thank you. – Linzer

Answer 2

Here is the .Net Way

    private bool dragging = false;
    private Point dragCursorPoint;
    private Point dragFormPoint;

    private void Form1_MouseDown(object sender, MouseEventArgs e)
    {
        dragging = true;
        dragCursorPoint = Cursor.Position;
        dragFormPoint = this.Location;
    }

    private void Form1_MouseMove(object sender, MouseEventArgs e)
    {
        if (dragging)
        {
            Point dif = Point.Subtract(Cursor.Position, new Size(dragCursorPoint));
            this.Location = Point.Add(dragFormPoint, new Size(dif));
        }
    }

    private void Form1_MouseUp(object sender, MouseEventArgs e)
    {
        dragging = false;
    }

that's it.

Raquelraquela

waow. perfect .net solution. thank you so much – Yeast

Answer 3

Just put the start point into an 2D Array like this:

public partial class mainForm : Form
{
    //Global variables for Moving a Borderless Form
    private bool dragging = false;
    private Point startPoint = new Point(0, 0); 


    public mainForm()
    {
        InitializeComponent();
    }

    private void mainForm_MouseDown(object sender, MouseEventArgs e)
    {
        dragging = true;
        startPoint = new Point(e.X, e.Y);

    }

    private void mainForm_MouseUp(object sender, MouseEventArgs e)
    {
        dragging = false;
    }

    private void mainForm_MouseMove(object sender, MouseEventArgs e)
    {
        if (dragging)
        {
            Point p = PointToScreen(e.Location);
            Location = new Point(p.X - this.startPoint.X, p.Y - this.startPoint.Y);

        }

    }
}

Drysalt

Answer 4

You can fake your menustrip, for example using a panel with a label instead. And then you can handle this manually: when the user clicks the label, a popup menu will open, and when the user drags the label, the window will move. But I would advise against such workarounds, because it's not a standard GUI behavior, and you might get your users confused.

Spokane

Please don't do this. Not only is it a completely non-standard user interface, but it still doesn't solve the problem of interpreting a click. Remember that a "drag" happens after a click occurs. Should a click open the menu, or should it be interpreted as beginning a drag? Time machines haven't been perfected yet. – Gaskill

@Cody A click happens when you release the mouse button. Look how it works in the Folders pane of Windows Explorer: if you click a folder, it opens in the right pane, but if you drag a folder, it doesn't open, it just gets dragged. – Spokane

Understood. But understand that you're defining a "Click" event differently from how a menu control interprets it in Windows. As soon as I press down the mouse button on any menu in any application in Windows, the menu drops down. It doesn't occur when the mouse button is released. I think it's important to point out that design decisions that dramatically alter expected behavior need to be considered especially carefully. – Gaskill

Answer 5

I haven't tried it, but if you can handle the "OnMouseDown" and "onMouseUp" events on the menu bar:

• On mouse down - Move the window according to the mouse movement
• Stop tracking the mouse movement on mouse up, or mouse out

Credible

Answer 6

If you are using a Panel you have to add this in the

YourForm.Designer.cs

this.panel1.MouseDown += new System.Windows.Forms.MouseEventHandler(this.panel1_MouseDown);

and this in the

YourForm.cs

 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();

        private void panel1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                ReleaseCapture();
                SendMessage(Handle, WM_NCLBUTTONDOWN, HT_CAPTION, 0);
            }
        }

Hunterhunting

Answer 7

Mbithi Kioko is on the right track but i would do it this way.

    bool dragging = false;
    int xOffset = 0;
    int yOffset = 0;

    private void Form1_MouseDown(object sender, MouseEventArgs e)
    {
        dragging = true;

        xOffset = Cursor.Position.X - this.Location.X;
        yOffset = Cursor.Position.Y - this.Location.Y;
    }

    private void Form1_MouseMove(object sender, MouseEventArgs e)
    {
        if (dragging)
        {
            this.Location = new Point(Cursor.Position.X - xOffset, Cursor.Position.Y - yOffset);
            this.Update();
        }
    }

    private void Form1_MouseUp(object sender, MouseEventArgs e)
    {
        dragging = false;
    }

Bullnecked

Answer 8

I had to use System.Runtime.InteropServices.DllImportAttribute - just thought I would comment and let you all know.

Acetate