UXML element DropdownField

A DropdownField lets users choose a value from a list. When clicking on the control, it opens a drawer that presents multiple options, allowing users to select one. If you want to always display all the choices, use RadioButtonGroup.

Respond to user actions

A DropdownField responds to Change events.

You can bind a DropdownField to a string variable that holds the selected choice value.

Add options for a DropdownField in UI Builder

To add options for a DropdownField, in the Inspector of the DropdownField, enter the options separated by commas in Choices.

To set the default value, in the Inspector of the DropdownField, enter the numbering sequence of the option in Index, starting at 0.

Create a DropdownField in C# script

The following C# code snippets create a DropdownField with three options. The DropdownField selects the first option by default.

var dropdown = new DropdownField("Options", new List<string> { "Option 1", "Option 2", "Option 3" }, 0);
dropdown.RegisterValueChangedCallback(evt => Debug.Log(evt.newValue));
rootVisualElement.Add(dropdown);

Change styles for a DropdownField

Override the default Panel Settings fields in a USS file to change the styles of a DropdownField in Unity:

1. In the Hierarchy window, select your UI Document (.uxml).
2. Set Panel Settings as your Panel Settings asset. If you don’t have an existing Panel Settings asset, follow the instructions in the dialog to create one.
3. In your Panel Settings asset, assign a Theme Style Sheet.
4. In the Project window, select your TSS file.
5. Go to Style Sheets and select the Add (+) button.
6. Set your Style Sheet as your USS file.

例

The best way to learn how to use DropdownField is to try an example. To see a DropdownField example, in Unity, select Window > UI Toolkit > Samples > DropdownField.

C# base class and namespace

C# class: DropdownField
Namespace: UnityEngine.UIElements
Base class: PopupField_1

Inherited UXML attributes

This element inherits the following attributes from its base class:

This element also inherits the following attributes from VisualElement:

USS classes

The following table lists all the C# public property names and their related USS selector.

その他の参考資料

• Change イベント
• RadioButtonGroup