Create a custom binding to bind USS selectors

Version: 2023.2+

This example shows how to create a custom binding that binds USS selectors to a visual element.

例の概要

This example creates a custom binding that assigns USS class selectors to each child element of a visual element based on the order of the child elements in the hierarchy. The first element always has the left round corner edge, while the last element always has the right round corner edge.

You can find the completed files that this example creates in this GitHub repository.

要件

このガイドは、Unity エディター、UI Toolkit、および C# スクリプトに精通している開発者を対象としています。始める前に、以下をよく理解してください。

• UI Builder
• UXML

Create a custom binding type

Create a custom binding type that assigns USS classes based on the sibling index. The binding updates only when the sibling index changes.

1. Unity で任意のテンプレートでプロジェクトを作成します。

2. In the Assets folder of your project, create a C# script named AddMenuUSSClass.cs with the following content:

   [!code-cs[(Modules/UIElements/Tests/UIElementsExamples/Assets/ui-toolkit-manual-code-examples/runtime-custom-binding/AddMenuUSSClass.cs)]

Create the UI and the binding

Generally speaking, you create a binding that binds to an existing property of the element. For demonstration purposes, this example creates a custom binding that binds to a property that doesn’t exist in the element. You must use UXML or C# to set up the binding that binds to a non-existing property. This example uses UXML to set up the binding.

1. In the Assets folder of your project, create a USS file named CustomBinding.uss with the following contents:

   [!code-cs[(Modules/UIElements/Tests/UIElementsExamples/Assets/ui-toolkit-manual-code-examples/runtime-custom-binding/CustomBinding.uss)]

2. In the Assets folder of your project, create a UXML file named CustomBinding.uxml with the following contents:

   [!code-cs[(Modules/UIElements/Tests/UIElementsExamples/Assets/ui-toolkit-manual-code-examples/runtime-custom-binding/CustomBinding.uxml)]

3. Double-click the CustomBinding.uxml file to open it in UI Builder.

4. In the StyleSheet panel, select + > Add Existing USS, and then select the CustomBinding.uss file.

5. 保存します。

バインディングのテスト

To test the binding, change the order of the button elements in the UI Builder and observe the changes in the UI Builder Viewport.

1. Double-click the CustomBinding.uxml file to open it in UI Builder.
2. In the Hierarchy panel, expand the root VisualElement to display the child elements, which are buttons.
3. Drag and drop the buttons to change their order. The first button always has the left round corner edge, while the last button always has the right round corner edge.

その他の参考資料

• Runtime data binding
• Create runtime data binding
• Create custom binding types