# DropDown<T> class

Namespace: [Grasshopper2.UI.Toolbar](https://developer.rhino3d.com/api/gh2/namespace/grasshopper2.ui.toolbar.md) · Assembly: [Grasshopper2](https://developer.rhino3d.com/api/gh2/assembly/grasshopper2.md)

```cs
public sealed class DropDown<T> : BarItem
```

A tool bar item which shows the currently selected value of a fixed set of options, and opens a menu with all the options when clicked. It takes up a single slot where a row of mutually exclusive toggles would take one slot per option.

**Type parameters:**

- `T`: Type of option values, typically an enum.

## Constructors

- [DropDown<T>](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/ctor.md): Create a new drop down item.

## Properties

- [AdjacentOnLeftSide](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/adjacentonleftside.md)
- [AdjacentOnRightSide](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/adjacentonrightside.md)
- [Value](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/value.md): Gets the value of the selected option, or the default value if there are no options.

## Methods

- [AddOption](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/addoption.md): Add an option. Options appear in the menu in the order they are added. Consecutive options with a different chapter or section are separated by a line.
- [DrawDisabled](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/drawdisabled.md)
- [DrawFocus](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/drawfocus.md)
- [DrawHover](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/drawhover.md)
- [DrawNormal](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/drawnormal.md)
- [MouseDown](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/mousedown.md)
- [MouseLeave](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/mouseleave.md)
- [MouseMove](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/mousemove.md)
- [MouseUp](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/mouseup.md)
- [SetValue](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/setvalue.md): Select the option with the given value, without raising [DropDown<T>.ValueChanged](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/valuechanged.md).
- [ShowMenu](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/showmenu.md): Show the menu with all options underneath this item.
- [ShowTooltipAt](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/showtooltipat.md)

## Events

- [ValueChanged](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/valuechanged.md): Raised when the user picks a different option. Not raised by [DropDown<T>.SetValue(T)](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.dropdown-1/setvalue.md).

## Inherited Members

- From [BarItem](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem.md): [Bar](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/bar.md), [Bounds](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/bounds.md), [Enabled](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/enabled.md), [Icon](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/icon.md), [KeyCode](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/keycode.md), [MaximumWidth](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/maximumwidth.md), [MinimumWidth](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/minimumwidth.md), [Nomen](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/nomen.md), [OffColour](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/offcolour.md), [OnColour](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/oncolour.md), [CreateOutline](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/createoutline.md), [Draw](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/draw.md), [DrawIcon](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/drawicon.md), [DrawIconAndText](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/drawiconandtext.md), [DrawText](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/drawtext.md), [FindGroupByChapter<T>](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/findgroupbychapter.md), [FindGroupBySection<T>](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/findgroupbysection.md), [HasNeighbourToTheLeft](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/hasneighbourtotheleft.md), [HasNeighbourToTheRight](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/hasneighbourtotheright.md), [IsEnabled](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/isenabled.md), [KeyDown](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/keydown.md), [KeyUp](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/keyup.md), [Layout](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/layout.md), [MouseDoubleClick](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/mousedoubleclick.md), [NeighbourToTheLeft](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/neighbourtotheleft.md), [NeighbourToTheRight](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/neighbourtotheright.md), [OverrideInfo](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/overrideinfo.md), [OverrideText](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/overridetext.md), [SetSizeLimits](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/setsizelimits.md), [TextInput](https://developer.rhino3d.com/api/gh2/type/grasshopper2.ui.toolbar.baritem/textinput.md)