I have a DropDownList combo box loaded with 10 items. I have assigned this to teh WinTree.Override.EditorControl. Everything work fine and Editor control shows properly. However, when an item is selected in the combo box, events such as ValueChanged, SelectionChanged do not fire. The problem is that I want to do different things based on the SelectionIndex. However, it is always 0.
This looks like you're trying to create a multi-select dropdown.
Although our Windows Forms controls don't currently include a multi-select dropdown, you can use our Windows Forms controls to get the same functionality. The following article from our online Knowledge Base provides more details; although the article is aimed at WinGrid, you can use this same approach in WinTree:HOWTO: Creating a Multi-Select Dropdown Combo for the WinGrid
I'm not sure I followed this, but the only way to get checkboxes to appear next to the items in UltraComboEditor's dropdown is using a draw filter or creation filter. The first hack that comes to mind is to assign an image to each item, then use the IUIElementCreationFilter interface to pull the image out, and replace it with a CheckBoxUIElement. The problem is that it will not respond to user interaction, since clicking on it will cause the dropdown to close. If this is not a concern, i.e., the checkbox is read-only anyway, you might also be able to show an image of a checkbox (have two images, one for each check state, assigning them based on what the item's "CheckState" is). If none of this is helpful, please repost with clarification and we can try to help.