Make a borderless form movable?

Question

Is there a way to make a form that has no border (FormBorderStyle is set to \"none\") movable when the mouse is clicked down on the form just as if there was a border?

Answer 1

I was trying to make a borderless windows form movable which contained a WPF Element Host control and a WPF User control.

I ended up with a stack panel called StackPanel in my WPF user control which seemed the logical thing to try click on to move. Trying junmats's code worked when I moved the mouse slowly, but if I moved the mouse faster, the mouse would move off the form and the form would be stuck somewhere mid move.

This improved on his answer for my situation using CaptureMouse and ReleaseCaptureMouse and now the mouse does not move off the form while moving it even if I move it quickly.

private void StackPanel_MouseDown(object sender, MouseButtonEventArgs e)
{
    _start_point = e.GetPosition(this);
    StackPanel.CaptureMouse();
}

private void StackPanel_MouseUp(object sender, MouseButtonEventArgs e)
{
    StackPanel.ReleaseMouseCapture();
}

private void StackPanel_MouseMove(object sender, MouseEventArgs e)
{
    if (StackPanel.IsMouseCaptured)
    {
        var p = _form.GetMousePositionWindowsForms();
        _form.Location = new System.Drawing.Point((int)(p.X - this._start_point.X), (int)(p.Y - this._start_point.Y));
    }
}

    //Global variables;
    private Point _start_point = new Point(0, 0);

Answer 2

Also if you need to DoubleClick and make your Form bigger/smaller , you can use the First answer, create a global int variable, add 1 every time user clicks on the component you use for dragging. If variable == 2 then make your form bigger/smaller. Also use a timer for every half a sec or a second to make your variable = 0;

Answer 3

   [DllImport("user32.DLL", EntryPoint = "ReleaseCapture")]
    private extern static void ReleaseCapture();

    [DllImport("user32.DLL", EntryPoint = "SendMessage")]
    private extern static void SendMessage(System.IntPtr hWnd, int Msg, int wParam, int lParam);
    private void panelTitleBar_MouseDown(object sender, MouseEventArgs e)
    {
        ReleaseCapture();
        SendMessage(this.Handle, 0x112, 0xf012, 0);
    }

Answer 4

Best way I've found (modified of course)

// This adds the event handler for the control
private void AddDrag(Control Control) { Control.MouseDown += new System.Windows.Forms.MouseEventHandler(this.DragForm_MouseDown); }
public const int WM_NCLBUTTONDOWN = 0xA1;
public const int HT_CAPTION = 0x2;
[System.Runtime.InteropServices.DllImportAttribute("user32.dll")]
public static extern int SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);
[System.Runtime.InteropServices.DllImportAttribute("user32.dll")]
public static extern bool ReleaseCapture();

private void DragForm_MouseDown(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        ReleaseCapture();
        SendMessage(Handle, WM_NCLBUTTONDOWN, HT_CAPTION, 0);
        // Checks if Y = 0, if so maximize the form
        if (this.Location.Y == 0) { this.WindowState = FormWindowState.Maximized; }
    }
}

To apply drag to a control simply insert this after InitializeComponent()

AddDrag(NameOfControl);

Answer 5

It worked for Me.

    private void Form1_MouseDown(object sender, MouseEventArgs e)
    {
        _mouseLoc = e.Location;
    }

    private void Form1_MouseMove(object sender, MouseEventArgs e)
    {
        if (e.Button == MouseButtons.Left)
        {
            int dx = e.Location.X - _mouseLoc.X;
            int dy = e.Location.Y - _mouseLoc.Y;
            this.Location = new Point(this.Location.X + dx, this.Location.Y + dy);
        }
    }

Answer 6

WPF only

---

don't have the exact code to hand, but in a recent project I think I used MouseDown event and simply put this:

frmBorderless.DragMove();

Window.DragMove Method (MSDN)