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GDScript 导出

导出简介

In Godot, class members can be exported. This means their value gets saved along with the resource (such as the scene) they're attached to. They will also be available for editing in the property editor. Exporting is done by using the @export annotation.

@export var number: int = 5

In that example the value 5 will be saved and visible in the property editor.

An exported variable must be initialized to a constant expression or have a type specifier in the variable. Some of the export annotations have a specific type and don't need the variable to be typed (see the Examples section below).

导出成员变量的基本好处之一是使它们在编辑器中可见并可编辑. 这样, 美术师和游戏设计师可以修改值, 这些值以后会影响程序的运行方式. 为此, 提供了一种特殊的导出语法.

备注

Exporting properties can also be done in other languages such as C#. The syntax varies depending on the language. See C# exports for information on C# exports.

Basic use

If the exported value assigns a constant or constant expression, the type will be inferred and used in the editor.

@export var number = 5

If there's no default value, you can add a type to the variable.

@export var number: int

Resources and nodes can be exported.

@export var resource: Resource
@export var node: Node

Grouping Exports

It is possible to group your exported properties inside the Inspector with the @export_group annotation. Every exported property after this annotation will be added to the group. Start a new group or use @export_group("") to break out.

@export_group("My Properties")
@export var number = 3

The second argument of the annotation can be used to only group properties with the specified prefix.

Groups cannot be nested, use @export_subgroup to create subgroups within a group.

@export_subgroup("Extra Properties")
@export var string = ""
@export var flag = false

You can also change the name of your main category, or create additional categories in the property list with the @export_category annotation.

@export_category("Main Category")
@export var number = 3
@export var string = ""

@export_category("Extra Category")
@export var flag = false

备注

The list of properties is organized based on the class inheritance and new categories break that expectation. Use them carefully, especially when creating projects for public use.

Strings as paths

String as a path to a file.

@export_file var f

String as a path to a directory.

@export_dir var f

String as a path to a file, custom filter provided as hint.

@export_file("*.txt") var f

Using paths in the global filesystem is also possible, but only in scripts in tool mode.

String as a path to a PNG file in the global filesystem.

@export_global_file("*.png") var tool_image

String as a path to a directory in the global filesystem.

@export_global_dir var tool_dir

The multiline annotation tells the editor to show a large input field for editing over multiple lines.

@export_multiline var text

Limiting editor input ranges

Allow integer values from 0 to 20.

@export_range(0, 20) var i

Allow integer values from -10 to 20.

@export_range(-10, 20) var j

Allow floats from -10 to 20 and snap the value to multiples of 0.2.

@export_range(-10, 20, 0.2) var k: float

The limits can be only for the slider if you add the hints "or_greater" and/or "or_less".

@export_range(0, 100, 1, "or_greater", "or_less")

Floats with easing hint

Display a visual representation of the 'ease()' function when editing.

@export_exp_easing var transition_speed

Colors

Regular color given as red-green-blue-alpha value.

@export var col: Color

Color given as red-green-blue value (alpha will always be 1).

@export_color_no_alpha var col: Color

节点

Since Godot 4.0, nodes can be directly exported as properties in a script without having to use NodePaths:

# Allows any node.
@export var node: Node

# Allows any node that inherits from BaseButton.
# Custom classes declared with `class_name` can also be used.
@export var some_button: BaseButton

Exporting NodePaths like in Godot 3.x is still possible, in case you need it:

@export var node_path: NodePath
var node = get_node(node_path)

If you want to limit the types of nodes for NodePaths, you can use the @export_node_path annotation:

@export_node_path("Button", "TouchScreenButton") var some_button

资源

@export var resource: Resource

In the Inspector, you can then drag and drop a resource file from the FileSystem dock into the variable slot.

Opening the inspector dropdown may result in an extremely long list of possible classes to create, however. Therefore, if you specify an extension of Resource such as:

@export var resource: AnimationNode

The drop-down menu will be limited to AnimationNode and all its inherited classes.

必须注意, 即使在编辑器中未运行脚本, 导出的属性仍可编辑. 可以与 使用工具模式的脚本 结合使用.

导出位标志

Integers used as bit flags can store multiple true/false (boolean) values in one property. By using the @export_flags annotation, they can be set from the editor:

# Set any of the given flags from the editor.
@export_flags("Fire", "Water", "Earth", "Wind") var spell_elements = 0

你必须为每个标志提供一个字符串描述。在这个例子中，Fire 的值是 1，Water 的值是 2，Earth 的值是 4，Wind 对应的值是 8。通常，应相应地定义常量（例如 const ELEMENT_WIND = 8 等等）。

You can add explicit values using a colon:

@export_flags("Self:4", "Allies:8", "Foes:16") var spell_targets = 0

Only power of 2 values are valid as bit flags options. The lowest allowed value is 1, as 0 means that nothing is selected. You can also add options that are a combination of other flags:

@export_flags("Self:4", "Allies:8", "Self and Allies:12", "Foes:16")
var spell_targets = 0

Export annotations are also provided for the physics, render, and navigation layers defined in the project settings:

@export_flags_2d_physics var layers_2d_physics
@export_flags_2d_render var layers_2d_render
@export_flags_2d_navigation var layers_2d_navigation
@export_flags_3d_physics var layers_3d_physics
@export_flags_3d_render var layers_3d_render
@export_flags_3d_navigation var layers_3d_navigation

使用位标志需要对位操作有一定的了解. 如果有疑问, 请使用布尔变量代替.

Exporting enums

Properties can be exported with a type hint referencing an enum to limit their values to the values of the enumeration. The editor will create a widget in the Inspector, enumerating the following as "Thing 1", "Thing 2", "Another Thing". The value will be stored as an integer.

enum NamedEnum {THING_1, THING_2, ANOTHER_THING = -1}
@export var x: NamedEnum

Integer and string properties can also be limited to a specific list of values using the @export_enum annotation. The editor will create a widget in the Inspector, enumerating the following as Warrior, Magician, Thief. The value will be stored as an integer, corresponding to the index of the selected option (i.e. 0, 1, or 2).

@export_enum("Warrior", "Magician", "Thief") var character_class: int

You can add explicit values using a colon:

@export_enum("Slow:30", "Average:60", "Very Fast:200") var character_speed: int

If the type is String, the value will be stored as a string.

@export_enum("Rebecca", "Mary", "Leah") var character_name: String

If you want to set an initial value, you must specify it explicitly:

@export_enum("Rebecca", "Mary", "Leah") var character_name: String = "Rebecca"

导出数组

导出的数组可以具有初始化器, 但是它们必须是常量表达式.

如果导出的数组指定了从 Resource 继承的类型，则可以通过一次从文件系统面板中拖放多个文件来在检查器中设置数组值。

The default value must be a constant expression.

@export var a = [1, 2, 3]

Exported arrays can specify type (using the same hints as before).

@export var ints: Array[int] = [1, 2, 3]

# Nested typed arrays such as `Array[Array[float]]` are not supported yet.
@export var two_dimensional: Array[Array] = [[1.0, 2.0], [3.0, 4.0]]

You can omit the default value, but it would then be null if not assigned.

@export var b: Array
@export var scenes: Array[PackedScene]

Arrays with specified types which inherit from resource can be set by drag-and-dropping multiple files from the FileSystem dock.

@export var textures: Array[Texture] = []
@export var scenes: Array[PackedScene] = []

Packed type arrays also work, but only initialized empty:

@export var vector3s = PackedVector3Array()
@export var strings = PackedStringArray()

从工具脚本设置导出变量

When changing an exported variable's value from a script in 工具模式, the value in the inspector won't be updated automatically. To update it, call notify_property_list_changed() after setting the exported variable's value.

高级导出

为了避免不必要的复杂设计，不是所有导出类型都在语言层面上提供。下面将说明一些能用底层 API 实现的，较为常见的导出方法。

Before reading further, you should get familiar with the way properties are handled and how they can be customized with _set(), _get(), and _get_property_list() methods as described in 从对象访问数据或逻辑.

参见

要在 C++ 中用上述方法绑定属性，请参阅 使用 _set/_get/_get_property_list 绑定属性。

警告

脚本必须在 tool 模式运行，上述方法才能在编辑器内运行。