I totally blew that one! (*Aims the USB Nerf dart gun at his own head and fires*)

If it's any help I'll recap what Mike said to do.

1. Drop a WinCalculatorDropDown down on your form and set the Visible property to false.
2. Set the CalculatorDropDownStyle to KeepCurrentValue.
3. Navigate to the properties of the columns, and change the EditorControl property of the Calculator Column to the WinCalculatorDropDown.

Sorry if I caused any confusion! I'll stay away for a while and go find a mountain dew to wake up.

Hi, 

Torrey, the article you linked to is about placing a control on a DropDownEditorButton. That's useful if you want a dropdown in a cell with some control on it that is NOT an embeddable editor already. But that is unneccessary here. UltraCalculatorDropDown is already an editor control, so using the code in that sample is just a whole lot of extra work for no reason. 

To get the value from the cell to show up in the calculator when you drop it down, all you have to to is set the CalculatorDropDownStyle on the UltraCalculatorDropDown control to KeepCurrentValue. 

Here's the steps to achieve what you're looking for. Keep in mind I'm assuming that your column that will contain the WinCalculator dropdown is of Decimal data type.

1. Add the WinNumericEditor and WinCalculator to your form.
2. Set the Visible properties for both to false.
3. Change the NumericType of the WinNumericEditor to Decimal.
4. Click the ellipse (...) for the ButtonsRight of the WinNumericEditor.
5. Add a DropDownEditorButton, and set the Control property to ultraCalculator1 (or whatever you named the control), and set the Key property to CalcButton.
6. Add a handler for the event BeforeEditorButtonDropDown on the WinNumericEditor.
7. Add a handler for the event AfterCalculationComplete on the WinCalculator.
8. Click the Start button on the grid to bring up the UltraGrid Designer.
9. Navigate to the properties of the columns, and change the EditorControl property of the Calculator Column to the WinNumericEditor.

Here's the code I used in the two created events for step 6 and 7.

        private void ultraCalculator1_AfterCalculationComplete(object sender, EventArgs e)
        {
            this.ultraGrid1.ActiveCell.Value = ultraCalculator1.DisplayValue;
        }

        private void ultraNumericEditor1_BeforeEditorButtonDropDown(object sender, Infragistics.Win.UltraWinEditors.BeforeEditorButtonDropDownEventArgs e)
        {
            if (this.ultraGrid1.ActiveCell != null && e.Button.Key == "CalcButton")
            {
                this.ultraGrid1.ActiveRow.Update();

                for (int i = 0; i < this.ultraGrid1.ActiveCell.Value.ToString().Length; i++)
                {
                    ultraCalculator1.PushButton(this.ultraGrid1.ActiveCell.Value.ToString().Substring(i,1));
                }
            }
        }

I would imagine there could be a cleaner way of coding for the BeforeEditorDropDown event, but nearly every property I found was read-only for the WinCalculator.

Thanks Torrey, but the problem here is that the CalcualtorDisplayValue has no setter.

If you read the documentation page I linked above it shows that you have to handle the BeforeEditorButtonDropDown event for the UltraCalculatorDropDown. Scroll toward the bottom of that page you'll see the code for this event (it's under #20), and you can do something similar for the UltraCalculatorDropDown. It's really easy!