Mouse scroll wheel changing UltraDropDown selection

Its funny that you should ask that now. After working on this issue off and on since my previous post (5+ months), I finally arrived at a solution last night. Its dissapointing that I had to spend so much time (I would guess days) to acheive what I beleive should be standard functionality (or at least a standard option). But as far as I'm concerned, I couldnt release the application the way it was - it would just casue to many problems.

Anyway, enough with my rant, onto the solution. I created a class to do this, to save writing it in each form individually.

declare an object varaible to store the value of the dropdown field:

private object _dropdownValue;

Then I add a ControlAdded event (ugSender is an UltraGrid):

ugSender.ControlAdded += new ControlEventHandler(ugSender_ControlAdded);

In ControlAdded event, put the code:

        void ugSender_ControlAdded(object sender, ControlEventArgs e)
        {
            string contType = sender.GetType().ToString();
            UltraGrid ugSender = sender as UltraGrid;
            UltraDropDown uddSender = ugSender.ActiveCell.ValueListResolved as UltraDropDown;
            if (uddSender != null)
            {
                e.Control.MouseWheel += new MouseEventHandler(Control_MouseWheel);
                e.Control.Enter += new EventHandler(Control_Enter);
                uddSender.AfterCloseUp += new DropDownEventHandler(uddSender_AfterCloseUp);
            }
        }

The uddSender_AfterCloseUp event looks like this:

        void uddSender_AfterCloseUp(object sender, DropDownEventArgs e)
        {
            UltraDropDown uddSender = sender as UltraDropDown;
            _dropdownValue = _ultraGrid.ActiveCell.Value;
        }

The Control_Enter event looks like this:

        void Control_Enter(object sender, EventArgs e)
        {
            Control conSender = sender as Control;
            UltraGrid ugSender = conSender.Parent as UltraGrid;
            if (ugSender != null)
            {
                UltraDropDown dropdown = ugSender.ActiveCell.ValueListResolved as UltraDropDown;
                if (dropdown != null)
                {
                    _dropdownValue = _ultraGrid.ActiveCell.Value;
                }
            }
        }

And the Control_MouseWheel event looks like this:

        void Control_MouseWheel(object sender, MouseEventArgs e)
        {
            Control conSender = sender as Control;
            UltraGrid ugSender = conSender.Parent as UltraGrid;
            if (ugSender != null)
            {
                UltraDropDown dropdown = ugSender.ActiveCell.ValueListResolved as UltraDropDown;
                if (dropdown != null)
                {
                    _ultraGrid.ActiveCell.Value = _dropdownValue;
                    ugSender.PerformAction(UltraGridAction.ExitEditMode, false, false);
                }
            }
        }

Whats happening here is:

When the user first enters the field, it records what the current value is (in _dropdownValue)
When the user changes the value by selecting it from the dropdown (in uddSender_AfterCloseUp) it is assigning the new value to _dropdownValue)
When the user uses the mousewheel, and the dropdown is not dropped down (in Control_MouseWheel), the code will change the ActiveCell's value back to the last selected value (_dropdownValue) as the mouse scrolling has already moved it one up or down at this point, and it then takes the control out of edit mode, so any subsequent mouse scrolls will scroll the whole ultragrid, as it should.

A few points.

I havnt really accounted for the user selecting a value by other means. I'm assuming if the user selects a value by typing something in, they will tab or enter to select it, which will then move the focus to another field - so there is no real issue here (I think).

I havnt really tested this a great deal. As I said, I just worked out this solution last night, so only basic testing has been done so far. If you find ways to improve it, please post it back here!

--- EDIT ---

The Control_MouseWheel event needs a little additional code, so that both of the lines:

_ultraGrid.ActiveCell.Value = _dropdownValue;

ugSender.PerformAction(UltraGridAction.ExitEditMode, false, false);

Are within another conditional statement

if (!dropdown.IsDroppedDown)

I did say I hadnt tested it much...