Hi Eliza,

The NumericEditor behaves the same way the TextBox control does by default. If you tab into the control, it selected all of the text. If you click on the control, it will place the caret at the point you clicked. Once you have entered the control and established a SelectionStart point, subsequently tabbing into the control will remember the last position of the caret and use that instead of selecting everything. All of this is just like a TextBox.

If you want to the control to always select the text, regardless of whether the user tabs into or clicks on it, then it's a little tricky. Calling SelectAll from AfterEnterEditMode would seem to be the obvious solution, but it doesn't work because the control enters edit mode on the MouseDown and then it positions the caret after that operation is complete. So the only way to to do this is to create some sort of delay and then select all of the text after the control's internal processing is complete.

One easy way to do that is by using a BeginInvoke:

        private void ultraNumericEditor1_AfterEnterEditMode(object sender, EventArgs e)
        {            
            this.BeginInvoke(new MethodInvoker(this.SelectAllTextInNumericEditor));            
        }

        private void SelectAllTextInNumericEditor()
        {
            this.ultraNumericEditor1.SelectAll();
        }

UltraNumericEditor and the masked editors do not have this functionality. You can Submit a Feature Request and perhaps this feature can be added in the future, but there's no way to do it right now.