Move windows form from a picturebox in C#

Question

I have a windows form without any border. So i added a picture box and i want the whole form to be moved when that picture box is clicked.

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

That is the code which i am using atm.But my problem is that if i move cursor very fast it is not sticked on the picture box.

I tried to find a solution but nothing came up. I used some info from those 2 links:

link 1

link 2

Any ideas?

EDIT: Here is the whole code of my form

    public Form1()
    {
        InitializeComponent();
    }

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

Answer 1

Refer this code:

 private bool draging = false;
        private Point pointClicked;
        private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
        {
            if (draging)
            {
                Point pointMoveTo;
                pointMoveTo = this.PointToScreen(new Point(e.X, e.Y));
                pointMoveTo.Offset(-pointClicked.X, -pointClicked.Y);
                this.Location = pointMoveTo;
            }
        }

        private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                draging = true;
                pointClicked = new Point(e.X, e.Y);
            }
            else
            {
                draging = false;
            }
        }

        private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
        {
            draging = false;
        }

Answer 2

Use the MouseMove() event instead of MouseDown():

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