Make a borderless form movable?
Solution 1:
This article on CodeProject details a technique. Is basically boils down to:
public const int WM_NCLBUTTONDOWN = 0xA1;
public const int HT_CAPTION = 0x2;
[System.Runtime.InteropServices.DllImport("user32.dll")]
public static extern int SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);
[System.Runtime.InteropServices.DllImport("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 essentially does exactly the same as grabbing the title bar of a window, from the window manager's point of view.
Solution 2:
Let's not make things any more difficult than they need to be. I've come across so many snippets of code that allow you to drag a form around (or another Control). And many of them have their own drawbacks/side effects. Especially those ones where they trick Windows into thinking that a Control on a form is the actual form.
That being said, here is my snippet. I use it all the time. I'd also like to note that you should not use this.Invalidate(); as others like to do because it causes the form to flicker in some cases. And in some cases so does this.Refresh. Using this.Update, I have not had any flickering issues:
private bool mouseDown;
private Point lastLocation;
private void Form1_MouseDown(object sender, MouseEventArgs e)
{
mouseDown = true;
lastLocation = e.Location;
}
private void Form1_MouseMove(object sender, MouseEventArgs e)
{
if(mouseDown)
{
this.Location = new Point(
(this.Location.X - lastLocation.X) + e.X, (this.Location.Y - lastLocation.Y) + e.Y);
this.Update();
}
}
private void Form1_MouseUp(object sender, MouseEventArgs e)
{
mouseDown = false;
}
Solution 3:
Another simpler way to do the same thing.
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
// set this.FormBorderStyle to None here if needed
// if set to none, make sure you have a way to close the form!
}
protected override void WndProc(ref Message m)
{
base.WndProc(ref m);
if (m.Msg == WM_NCHITTEST)
m.Result = (IntPtr)(HT_CAPTION);
}
private const int WM_NCHITTEST = 0x84;
private const int HT_CLIENT = 0x1;
private const int HT_CAPTION = 0x2;
}
Solution 4:
use MouseDown, MouseMove and MouseUp. You can set a variable flag for that. I have a sample, but I think you need to revise.
I am coding the mouse action to a panel. Once you click the panel, your form will move with it.
//Global variables;
private bool _dragging = false;
private Point _offset;
private Point _start_point=new Point(0,0);
private void panel1_MouseDown(object sender, MouseEventArgs e)
{
_dragging = true; // _dragging is your variable flag
_start_point = new Point(e.X, e.Y);
}
private void panel1_MouseUp(object sender, MouseEventArgs e)
{
_dragging = false;
}
private void panel1_MouseMove(object sender, MouseEventArgs e)
{
if(_dragging)
{
Point p = PointToScreen(e.Location);
Location = new Point(p.X - this._start_point.X,p.Y - this._start_point.Y);
}
}