Struct Select 

pub struct Select { /* private fields */ }

A dropdown select widget.

Displays the currently selected option when collapsed (“▼”), and expands inline to show all options with keyboard navigation when activated.

Implementations

impl Select

pub fn new() -> Self

Creates an empty select.

pub fn options(self, options: Vec<impl Into<Text>>) -> Self

Sets the option list.

pub fn style(self, style: Style) -> Self

Sets the collapsed/default style.

pub fn selected_style(self, style: Style) -> Self

Sets the selected option style.

pub fn selected(&self) -> usize

Returns the currently selected index.

pub fn selected_text(&self) -> &str

Returns the text of the currently selected option.

pub fn set_selected(&mut self, index: usize, cx: &mut EventCx<'_>)

Sets the selected option.

Trait Implementations

impl Component for Select

fn render(&self, cx: &mut RenderCx<'_>)

渲染组件内容

fn measure(&self, _constraint: Constraint, _cx: &mut MeasureCx) -> Size

测量组件在给定约束下的自适应尺寸

fn event(&mut self, event: &Event, cx: &mut EventCx<'_>)

处理事件（可选实现）

fn layout(&mut self, rect: Rect, _cx: &mut LayoutCx<'_>)

布局回调——组件在此计算子节点 rect 并调用 child.layout()

fn focusable(&self) -> bool

是否可聚焦（Tab 导航会跳过不可聚焦的组件）

fn style(&self) -> Style

返回组件样式（可选实现）

fn mount(&mut self, _cx: &mut EventCx<'_>)

首次挂载（初始化后调用）

fn unmount(&mut self, _cx: &mut EventCx<'_>)

从树卸载（退出前调用）

fn update(&mut self, _cx: &mut EventCx<'_>)

每次事件分发前调用

fn type_name(&self) -> &str

组件类型名（用于样式表类型选择器匹配）

fn id(&self) -> Option<&str>

组件 ID（用于样式表 #id 选择器匹配）

fn class(&self) -> Option<&str>

组件 class（用于样式表 .class 选择器匹配）

fn for_each_child(&self, _f: &mut dyn FnMut(&Node))

遍历子节点（为焦点系统等提供统一的树遍历接口）

fn for_each_child_mut(&mut self, _f: &mut dyn FnMut(&mut Node))

遍历子节点（可变版本）