How to make a borderless form draggable on a custom title bar?

Question

I have created a border-less form using c# but could make the custom title bar movable so I search the internet and found this code:

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;

After applying this code can click and drag my form in every inch of the form except for the title bar.

Answer 1

NOTE: although this is a very old answer, I tested it on .NET 8 and it still works

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Movable custom title bar

using System;
using System.Drawing;
using System.Windows.Forms;

public partial class MainForm : Form
{
    private readonly PictureBox title = new PictureBox();    // create a PictureBox
    private readonly Label minimise = new Label();           // this doesn't even have to be a label!
    private readonly Label maximise = new Label();           // this will simulate our this.maximise box
    private readonly Label close = new Label();              // simulates the this.close box

    private bool drag = false;                      // determine if we should be moving the form
    private Point startPoint = new Point(0, 0);     // also for the moving

    public MainForm()
    {
        this.FormBorderStyle = FormBorderStyle.None;// get rid of the standard title bar

        this.title.Location = this.Location;        // assign the location to the form location
        this.title.Width = this.Width;              // make it the same width as the form
        this.title.Height = 50;                     // give it a default height (you may want it taller/shorter)
        this.title.BackColor = Color.Black;         // give it a default colour (or load an image)
        this.Controls.Add(this.title);              // add it to the form's controls, so it gets displayed
        // if you have an image to display, you can load it, instead of assigning a bg colour
        // this.title.Image = new Bitmap(System.Environment.CurrentDirectory + "\\title.jpg");
        // if you displayed an image, alter the SizeMode to get it to display as you want it to
        // examples:
        // this.title.SizeMode = PictureBoxSizeMode.StretchImage;
        // this.title.SizeMode = PictureBoxSizeMode.CenterImage;
        // this.title.SizeMode = PictureBoxSizeMode.Zoom;
        // etc          

        // you may want to use PictureBoxes and display images
        // or use buttons, there are many alternatives. This is a mere example.
        this.minimise.Text = "Minimise";        // Doesn't have to be
        this.minimise.Location = new Point(this.Location.X + 5, this.Location.Y + 5); // give it a default location
        this.minimise.ForeColor = Color.Red;    // Give it a colour that will make it stand out
        // this is why I didn't use an image, just to keep things simple:
        this.minimise.BackColor = Color.Black;  // make it the same as the PictureBox
        this.Controls.Add(this.minimise);       // add it to the form's controls
        this.minimise.BringToFront();           // bring it to the front, to display it above the picture box

        this.maximise.Text = "Maximise";
        // remember to make sure it's far enough away so as not to overlap our minimise option
        this.maximise.Location = new Point(this.Location.X + 60, this.Location.Y + 5);
        this.maximise.ForeColor = Color.Red;
        this.maximise.BackColor = Color.Black;  // remember, we want it to match the background
        this.maximise.Width = 50;
        this.Controls.Add(this.maximise);       // add it to the form
        this.maximise.BringToFront();

        this.close.Text = "Close";
        this.close.Location = new Point(this.Location.X + 120, this.Location.Y + 5);
        this.close.ForeColor = Color.Red;
        this.close.BackColor = Color.Black;
        this.close.Width = 37;                  // this is just to make it fit nicely
        this.Controls.Add(this.close);
        this.close.BringToFront();

        // now we need to add some functionality. First off, let's give those labels
        // MouseHover and MouseLeave events, so they change colour
        // Since they're all going to change to the same colour, we can give them the same
        // event handler, which saves time of writing out all those extra functions
        this.minimise.MouseEnter += new EventHandler(Control_MouseEnter);
        this.maximise.MouseEnter += new EventHandler(Control_MouseEnter);
        this.close.MouseEnter += new EventHandler(Control_MouseEnter);

        // and we need to do the same for MouseLeave events, to change it back
        this.minimise.MouseLeave += new EventHandler(Control_MouseLeave);
        this.maximise.MouseLeave += new EventHandler(Control_MouseLeave);
        this.close.MouseLeave += new EventHandler(Control_MouseLeave);

        // and lastly, for these controls, we need to add some functionality
        this.minimise.MouseClick += new MouseEventHandler(Control_MouseClick);
        this.maximise.MouseClick += new MouseEventHandler(Control_MouseClick);
        this.close.MouseClick += new MouseEventHandler(Control_MouseClick);

        // finally, wouldn't it be nice to get some moveability on this control?
        this.title.MouseDown += new MouseEventHandler(Title_MouseDown);
        this.title.MouseUp += new MouseEventHandler(Title_MouseUp);
        this.title.MouseMove += new MouseEventHandler(Title_MouseMove);
    }

    private void Control_MouseEnter(object sender, EventArgs e)
    {
        if (sender.Equals(this.close))
            this.close.ForeColor = Color.White;
        else if (sender.Equals(this.maximise))
            this.maximise.ForeColor = Color.White;
        else // it's the minimize label
            this.minimise.ForeColor = Color.White;
    }

    private void Control_MouseLeave(object sender, EventArgs e)
    {
        // return them to their default colors
        if (sender.Equals(this.close))
            this.close.ForeColor = Color.Red;
        else if (sender.Equals(this.maximise))
            this.maximise.ForeColor = Color.Red;
        else // it's the minimise label
            this.minimise.ForeColor = Color.Red;
    }

    private void Control_MouseClick(object sender, MouseEventArgs e)
    {
        if (sender.Equals(this.close))
            this.Close(); // close the form
        else if (sender.Equals(this.maximise))
        {
            // maximise is more interesting. We need to give it different functionality,
            // depending on the window state (Maximise/Restore)
            if (this.maximise.Text == "Maximise")
            {
                this.WindowState = FormWindowState.Maximized;   // maximise the form
                this.maximise.Text = "Restore";                 // change the text
                this.title.Width = this.Width;                  // stretch the title bar
            }
            else // we need to restore
            {
                this.WindowState = FormWindowState.Normal;
                this.maximise.Text = "Maximise";
            }
        }
        else // it's the minimise label
            this.WindowState = FormWindowState.Minimized;       // minimise the form
    }

    void Title_MouseUp(object sender, MouseEventArgs e)
    {
        this.drag = false;
    }

    void Title_MouseDown(object sender, MouseEventArgs e)
    {
        this.startPoint = e.Location;
        this.drag = true;
    }

    void Title_MouseMove(object sender, MouseEventArgs e)
    {
        if (this.drag)
        {
            // if we should be dragging it, we need to figure out some movement
            Point p1 = new Point(e.X, e.Y);
            Point p2 = this.PointToScreen(p1);
            Point p3 = new Point(p2.X - this.startPoint.X,
                                 p2.Y - this.startPoint.Y);
            this.Location = p3;
        }
    }
}

If you want you can extract just the moving code and integrate it with your code, the movable Title code is just in the following Event Handlers

• Title_MouseUp

• Title_MouseDown

• Title_MouseMove

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Here is the original article for this code, you can read it for more explanation about the code
http://www.dreamincode.net/forums/topic/64981-designing-a-custom-title-bar/
The link to original article is broken