UQuery を使用すると、ビジュアルツリー から要素を見つけることができます。UQuery は JQuery と Linq に発想を得て、動的なメモリ割り当てを制限するように設計されています。これにより、モバイルプラットフォームで最適なパフォーマンスを実現できます。
You can use UQuery through the Q
and Query
extension methods. Internally, the Q
and Query
methods use UQueryBuilder
to construct a query. These extension methods reduce the verbosity of creating a UQueryBuilder
.
To use UQuery to find elements, you must load and instantiate the UXML first.
To use Query
and Q
, construct specified selections rules on a root visual element. Query
returns a list of elements that match the selection rules. Q
is the shorthand for Query<T>.First()
. It returns the first element that matches the selection rules.
You can filter the return results of Query
with the public methods of UQueryBuilder
, such as First, Last, AtIndex, Children, and Where.
You can query elements by their name, their USS class, or their element type(C# type). You can also query with a predicate or make complex hierarchical queries.
以下のセクションでは、この例の UXML を使用して、要素の検索方法を説明します。
<UXML xmlns="UnityEngine.UIElements">
<VisualElement name="container1">
<Button name="OK" text="OK" />
<Button name="Cancel" text="Cancel" />
</VisualElement>
<VisualElement name="container2">
<Button name="OK" class="yellow" text="OK" />
<Button name="Cancel" text="Cancel" />
</VisualElement>
<VisualElement name="container3">
<Button name="OK" class="yellow" text="OK" />
<Button name="Cancel" class="yellow" text="Cancel" />
</VisualElement>
</UXML>
To find elements by their name, use Query(name: "element-name")
or Q(name: "element-name")
. You can omit name
as it’s the first argument. For example:
//Find a list of elements named "Ok".
List<VisualElement> result1 = root.Query("OK").ToList();
//Find the first element named "Ok" and add a tooltip for it.
VisualElement result2 = root.Query("OK").First(); //or VisualElement result = root.Q("OK");
result.tooltip = "This is a tooltip!";
//Find the second element named "Ok".
VisualElement result3 = root.Query("OK").AtIndex(1);
//Find the last element named "Ok".
VisualElement result4 = root.Query("OK").Last();
To find elements by a USS class, use Query(className: "class-name")
or Q(className: "class-name")
. For example:
//Find all the elements that have the class "yellow" and assign them to a list.
List<VisualElement> result = root.Query(className: "yellow").ToList();
//Find the first element that has the class "yellow".
VisualElement result = root.Q(className: "yellow");
To find elements by their element type(C# type), use Query<Type>
or Q<Type>
. For example:
//Find the first button and add a tooltip for it.
VisualElement result = root.Q<Button>();
result.tooltip = "This is a tooltip!";
//Find the third button.
VisualElement result = root.Query<Button>().AtIndex(2);
ノート: 基本クラスではなく、要素の実際の型によってのみクエリを行うことができます。
Other than to query element by name, class, and type, you can also use the Where
method to select all elements that satisfy a predicate. The predicate must be a function callback that takes a single VisualElement
argument. For example, the following code snippet finds the all the elements with the “yellow” USS class that have no tool tips:
List<VisualElement> result = root.Query(className: "yellow").Where(elem => elem.tooltip == "").ToList();
You can combine name, class, and type to make complex hierarchical queries. For example:
//Find the first button named "OK" that has a class of "yellow".
VisualElement result = root.Query<Button>(className: "yellow", name: "OK").First();
result.tooltip = "This is a tooltip!";
//Find the child cancel button of the "container2".
VisualElement result = root.Query<VisualElement>("container2").Children<Button>("Cancel").First();
You can use the ForEach method to operate directly on the query results. For example, the following code snippet adds a tool tip for any elements that have no tool tips:
root.Query().Where(elem => elem.tooltip == "").ForEach(elem => elem.tooltip="This is a tooltip!");
UQuery を使用する際は、以下の点を考慮してください。
QueryState
構造体 (element.Query()
メソッドで返されます) を使用し、リストの作成を避けるために列挙します。また、クエリを一度構築し、異なる要素に対して実行することもできます。VisualElement
変数をキャプチャします。Did you find this page useful? Please give it a rating:
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