Question

I have a form created in Windows Forms which is draggable wherever I click. I made it by overriding WndProc function which in turn modifies each click as it was a title bar click:

    //found at: http://stackoverflow.com/questions/3995009/how-to-make-a-window-draggablec-winforms
    private const int WM_NCHITTEST = 0x84;
    private const int HTCLIENT = 0x1;
    private const int HTCAPTION = 0x2;

    ///
    /// Handling the window messages 
    ///
    protected override void WndProc(ref Message message)
    {
        base.WndProc(ref message);

        if (message.Msg == WM_NCHITTEST && (int)message.Result == HTCLIENT)
            message.Result = (IntPtr)HTCAPTION;
    }

The problem is that now when I double click, the window becomes fullscreen, which is unwanted. How can I block this behavior?

Answer 1

In addition to JaredPar I would suggest don not create draggable form in that way, but handle it in 3 steps

• identify mouse down on the form
• capture mouse
• identify mouse up event

It is not a complicated to handle, and it’s better, imo, then disabling a double click on the form.

For complete example of how you can do that can have a look on

Creating a Draggable Borderless Form