I am using above code. But it displays nothing. When will InstantiateIn() function called?

Hello,

 I'm not sure if you have gotten it working yet but here is the solution to make it look like a dropdownlist

public void InstantiateIn(System.Web.UI.Control container)
 {
 Infragistics.WebUI.UltraWebGrid.CellItem cellitem1 = ((Infragistics.WebUI.UltraWebGrid.CellItem)(container));
 WebCombo combo = new WebCombo();
 cellitem1.Controls.Add(combo);
 //Set data source

 //Set the webcombo to be editable

combo.Editable = true;
 combo.Width = Unit.Pixel(100);
 combo.DropDownLayout.DropdownWidth = Unit.Pixel(104);
 combo.DropDownLayout.DropdownHeight = Unit.Pixel(70);
 combo.DropDownLayout.ColHeadersVisible = Infragistics.WebUI.UltraWebGrid.ShowMarginInfo.No;
 combo.DropDownLayout.RowSelectors = Infragistics.WebUI.UltraWebGrid.RowSelectors.No;
 }

All you need to do is use these 5 lines of code

 combo.Width = Unit.Pixel(100);
 combo.DropDownLayout.DropdownWidth = Unit.Pixel(104);
 combo.DropDownLayout.DropdownHeight = Unit.Pixel(70);
 combo.DropDownLayout.ColHeadersVisible = Infragistics.WebUI.UltraWebGrid.ShowMarginInfo.No;
 combo.DropDownLayout.RowSelectors = Infragistics.WebUI.UltraWebGrid.RowSelectors.No;

To set the combo to be editable:

combo.Editable = true;

Hope that helps,

HS2