Hi,

Do I understand correctly that you are using BeginUpdate and EndUpdate inside the InitializeRow event surrounding the code that set the ValueList property on the cell?

If that's the case, have you tried removing the BeginUpdate/EndUpdate from that event?

It seems to me that calling these methods inside InitializeRow is a bad idea and will probably slow your application down rather than speed it up.

Invalidating the grid (or any portion of it) is a very fast operation. So causing an invalidate inside InitializeRow should not cause a problem.

But once you call EndUpdate, you are forcing the grid to paint, which is much more expensive and that could certainly slow things down.

BeginUpdate and EndUpdate are intended for use when you are performing a lot of operations all at once. So using them inside InitializeRow doesn't make a lot of sense and could actually cause problems.

Also.... Assigning a ValueList to each cell in the column is probably not a good idea, anyway. You might want to check out this article which explains a better way to achieve different lists on each row.

Creating a dropdown list in a grid cell whose list values are dependent on another cell - Windows Forms - Infragistics Community

First row is active selected value (we have background image stretched), 4th row - HotTrack'ed (HotTrackRowCellAppearance.BackColor set).

Standard ValueList looks like this:

How do I achieve the following:

a) We use AppStylist and GridRow role has Selected/Active states with background images. How to reset/override these images, so UltraDropDown would show not image, but ValueList style (orange color with border) for Selected/Active row. Resetting/clearing e.Layout.Override.ActiveRowAppearance, SelectedRowAppearance background on UltraDropDown did not help - or I've reset incorrect properties.

b) How to achieve border around hot-tracked UltraDropDown item, as seen in ValueList.

c) How to properly share code in forum - with tabs, syntax highlight, etc :)

Here is the code I've used so far (maybe some will find it usefull):

In UltraDropDown initialize layout:

e.Layout.BorderStyle = UIElementBorderStyle.Rounded1;

e.Layout.Override.BorderStyleCell = UIElementBorderStyle.None;
e.Layout.Override.RowAppearance.BorderAlpha = Alpha.Transparent;

e.Layout.ScrollStyle = ScrollStyle.Immediate;
e.Layout.Scrollbars = Scrollbars.Vertical;

e.Layout.Appearance.BackColor = Color.White;
e.Layout.Override.HotTrackRowCellAppearance.BackColor = Color.FromArgb(255, 171, 63);

e.Layout.AutoFitStyle = AutoFitStyle.ExtendLastColumn;

Main creation filter method for UltraDrop down to size/position correctly:

void IUIElementCreationFilter.AfterCreateChildElements(UIElement parent)
{
    if (parent is UltraGridUIElement)
    {
        UltraGridUIElement gridUiElement = (UltraGridUIElement)parent;

        // Get drop down control:
        Control dropDownControl = gridUiElement.Control.Parent;

        // Get active cell from where drop-down is invoked:
        UltraGridCell cell = this.gridControl.ActiveCell;

        // This method is called more than once, the first time the drop-down section
        // is not attached to the UIElements, which explains this "if".
        if (dropDownControl != null && cell != null)
        {
            // Calculate maximum width of drop-down by drop-down column width:
           UltraGridColumn dropDownColumn = null;
           UltraGridLayout layout = gridUiElement.Grid.DisplayLayout;if (layout.Bands.Count > 0)
           {
               // Get drop-down grid column:
               if (layout.Bands[0].Columns.Exists(this.columnName))
                    dropDownColumn = layout.Bands[0].Columns[this.columnName];
           }

           int width = -1;
         
           // Get column widht:
          if (dropDownColumn != null)
          {
               width = dropDownColumn.CalculateAutoResizeWidth(PerformAutoSizeType.VisibleRows, false);
               width += 25; // Scroll bar width ~ should be get from somewhere?
           }

           // Get UI element of active cell:
           UIElement cellElement = cell.GetUIElement();
           if (cellElement != null)
           {
               Rectangle cellRect = cellElement.Rect;

               // If cell width is more than required for drop-down control, expand drop-down:
               if (cellRect.Width > width)
                         width = cellRect.Width;

               // Set drop-down width:
               dropDownControl.Width = width;

               // Calculate drop-down location:
               Point location = new Point(cellRect.Right - width, cellRect.Bottom);
               location = this.gridControl.PointToScreen(location);

               // Set drop-down location:
               dropDownControl.Left = location.X;

             }

        }

   }

}