Move form when the form is clicked, not the topbar area

Question

I'm working on making a program that has no control box, because I don't want one. I am trying to make it so that when I click any area that is not a control, it will move. This is the code I have so far:

    public Form1()
    {
        InitializeComponent();
        BackColor = Color.linen;
        TransparencyKey = Color.Linen;
    }
    bool canMove = false;
    int mouseX;
    int mouseY;
    public void MoveForm()
    {
        mouseX = MousePosition.X - Form1.ActiveForm.Location.X;
        mouseY = MousePosition.Y - Form1.ActiveForm.Location.Y;
        Form1.ActiveForm.Location = new Point(mouseX, mouseY);
    }

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

    private void Form1_MouseMove(object sender, MouseEventArgs e)
    {
        if (canMove)
            MoveForm();

    }

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

That works for moving, but if the form is at an edge, it will not show up right. Another thing it does, is flashes when it is getting dragged.

Is there any way I can correctly do this?

Your flickering occurs because when your mouse button is down and you move, it start generating mouse move events even if your mouse is in the same position! It is like a timer. One move and the move events doesnt stop. — γηράσκω δ' αεί πολλά διδασκόμε, Feb 19 '14 at 02:36
One way to deal with it is to use the relative position of the mouse to screen coordinates. If it is the same don't call MoveForm(). — γηράσκω δ' αεί πολλά διδασκόμε, Feb 19 '14 at 02:38
possible duplicate of [C# - Make a borderless form movable?](http://stackoverflow.com/questions/1592876/c-sharp-make-a-borderless-form-movable) — Shell, Feb 19 '14 at 03:50

score 2 · Accepted Answer · answered Feb 19 '14 at 03:11

Just add this code to form and you're done:

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private const int HTCLIENT = 0x0001;
    private const int HTCAPTION = 0x0002;
    private const int WM_NCHITTEST = 0x0084;

    protected override void WndProc(ref Message m)
    {
        base.WndProc(ref m);
        if ((m.Msg == WM_NCHITTEST) & (m.Result.ToInt32() == HTCLIENT))
        {
            m.Result = (IntPtr)HTCAPTION;
        }
    }

}

Works flawless! Thanks a lot! – Dozer789 Feb 19 '14 at 15:19 — Dozer789, Feb 19 '14 at 15:19

γηράσκω δ' αεί πολλά διδασκόμε · Answer 2 · 2014-02-19T03:08:49.037

The code is in vb (sorry):

Private posx, posy As Integer

Private Sub Form1_MouseDown(sender As System.Object, e As System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseDown
    canMove = 1

    posx = MousePosition.X
    posy = MousePosition.Y
End Sub

Private Sub Form1_MouseMove(sender As System.Object, e As System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseMove
    If canMove = 1 And (posx <> MousePosition.X Or posy <> MousePosition.Y) Then
        MoveForm()
    End If

    posx = MousePosition.X
    posy = MousePosition.Y
End Sub

It does go back and forth(its because of your code in MoveForm()) but if you don't move the mouse it stops.

Edit: in c# (used translator)

int posx, posy;
private void Form1_MouseDown(object sender, MouseEventArgs e)
{
    canMove = true;
    posx = MousePosition.X;
    posy = MousePosition.Y;
}

private void Form1_MouseMove(object sender, MouseEventArgs e)
{
    if (canMove == 1 && (posx != MousePosition.X || posy != MousePosition.Y)) {
        MoveForm();
    }

    posx = MousePosition.X;
    posy = MousePosition.Y;
}

valter

Works better than before, but it still flashes between 2 locations. I'm going to use Idle_Mind's solution because it is shorter, and it looks better. Thanks for trying to help! — Dozer789, Feb 19 '14 at 15:18

Move form when the form is clicked, not the topbar area

2 Answers2