选择器
使用集合让一切井井有条
根据您的偏好保存内容并对其进行分类。
选择器可帮助用户选择和设置特定数据。
选择器
选择器应用于让用户从有限数量的项中进行选择。
默认情况下，项会在两个方向上无限循环。如果列表顺序很重要，请考虑停用此行为；或者，允许用户通过快速滑动访问第一个和最后一个元素。
解剖学
解剖
A. 非活动列
B. 冒号分隔符
C. 选择器列
D. 热门内容
E. 中间内容
F. 底部内容
宽度和高度
选择器组会填充可用的高度和宽度。选择器列有四种布局选项。每个布局都居中显示，并填充可用高度。列宽由字体中所需数字数量所需的宽度定义，日期选择器是例外，它会水平填满屏幕并超出边缘。
例如，数字会计算“00”的宽度，然后设置宽度。对于文本字段（例如月份字段），宽度将计算为“MMM”（拉丁字母中最宽的字母）的宽度。因此，宽度和高度（即所用字体样式的行高）将受到所用字体的制约。
选择器项在不同断点上的大小不同。
用法
请参阅以下日期和时间选择器示例
如需了解预构建的日期和时间选择器实现，请查看 GitHub 上的 Horologist 库。
如果您想创建类似的体验，让用户从多个选择器中选择一个多部分值，请使用内置的 PickerGroup 组件。此对象使用焦点协调器对象将焦点分配给正确的 Picker 元素。
自适应布局
TimePicker 24 小时制
12 小时制 TimePicker
日期选择器
响应式行为
放大文字大小
超过 225 的断点后，Picker 元素的字号会发生变化。延迟滚动列中的顶部和底部副本会调整（A），中间副本也会调整。以下是一些示例：
两列布局
低于 225 dp 断点
字体：Display 2
高于 225 dp 断点
字体：Display 1
三列布局
低于 225 dp 断点
字体：Display 3
渐变大小增加
选择器列上的渐变高度由可用空间定义。顶部和底部渐变均设置为可用高度的三分之一 (33%)。这意味着，在每种可用屏幕尺寸下，渐变色都会按比例缩放。独立于列布局。
增大列间距
列间距在超过 225+ 断点后会按比例缩放，从 2dp 或 4dp 开始，并增至 6dp。这取决于您选择的布局（2 列或 3 列布局）
两列布局
三列布局
本页面上的内容和代码示例受内容许可部分所述许可的限制。Java 和 OpenJDK 是 Oracle 和/或其关联公司的注册商标。
最后更新时间 (UTC)：2025-07-27。
[null,null,["最后更新时间 (UTC)：2025-07-27。"],[],[],null,["# Pickers\n\nThe [Picker](/reference/kotlin/androidx/wear/compose/material/package-summary#Picker(androidx.wear.compose.material.PickerState,androidx.compose.ui.Modifier,kotlin.Boolean,kotlin.Function1,androidx.wear.compose.material.ScalingParams,androidx.compose.ui.unit.Dp,kotlin.Float,androidx.compose.ui.graphics.Color,androidx.compose.foundation.gestures.FlingBehavior,kotlin.Function2)) helps users select and set specific data. \n**Picker**\n\nPickers should be used to let users choose amongst a finite number of items. \n\nBy default items will be looped infinitely in both directions. Consider disabling this behaviour if order in the list is important, or to allow users to reach the first and last element with a quick swipe.\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\nAnatomy\n-------\n\n**Anatomy**\n\nA. Inactive Column \n\nB. Colon Breaker \n\nC. Picker Column \n\nD. Top Content \n\nE. Middle Content \n\nF. Bottom Content\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n**Widths and heights**\n\nThe Picker Group fills the available height and width. There are four layout options for the picker columns. Each layout is centred and fills the available height. Column widths are defined by the width needed to accommodate the number of digits needed in the font, Date-picker is the exception, horizontally it fills the screen and bleeds off the edge.\n\nFor example numbers will work out width of '00' is and then set the width. For text fields, for the month field for example, will be worked out as the width of 'MMM' (which is the widest letter in the latin alphabet). The width and height (which is the line height of that type style used) will therefore be affected by the font used.\n\nPicker items vary in size across the breakpoint.\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\nUsage\n-----\n\nSee the following examples of Date and Time Pickers\n\nFor a prebuilt date and time picker implementation, check out the [Horologist Library](https://github.com/google/horologist#-composables) on GitHub. \n\n\nIf you want to create a similar experience, where users choose a multi-part value across multiple pickers, use the built-in [PickerGroup](/reference/kotlin/androidx/wear/compose/material/package-summary#PickerGroup(kotlin.Array,androidx.compose.ui.Modifier,androidx.wear.compose.material.PickerGroupState,kotlin.Function1,kotlin.Boolean,kotlin.Boolean,androidx.wear.compose.material.TouchExplorationStateProvider,kotlin.Function1)) component. This object uses a focus coordinator object to assign focus to the correct Picker element.\n\nAdaptive layouts\n----------------\n\n**TimePicker 24H**\n\n**TimePicker 12H**\n\n**Date Picker**\n\n**Responsive behavior**\n-----------------------\n\n### **Text size increase**\n\nPast the 225+ Breakpoint, the Picker element's font size changes. Top and Bottom copy within the lazy scrolling column adjusts (A), as does the Middle copy. Below are some examples of this:\n\n**Two column layout** \n**Below the 225 dp breakpoint**\n\nFont: Display 2 \n**Above 225 dp breakpoint**\n\nFont: Display 1\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n**Three column layout** \n**Below the 225 dp breakpoint**\n\nFont: Display 3 \n**Above the 225 dp breakpoint**\n\nFont: Display 2\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n**Gradient size increase**\n--------------------------\n\nThe gradient on the Picker column is defined in height by the available space. Both Top and Bottom Gradients are set at a third (33%) of the available height. This means at each available screen size, the gradient scales proportionally. Sitting independent of the column layout. \n**Below the 225 dp breakpoint**\n\nSize: 33% of column height \n**Above the 225 dp breakpoint**\n\nSize: 33% of column height\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n**Column spacing increase**\n---------------------------\n\nColumn spacing scales past the 225+ Breakpoint, either starting at 2 dp or 4 dp and growing to 6 dp. This depends on which layout you've selected; either 2 or 3 column layouts\n\n**Two column layout** \n**Below the 225 dp breakpoint**\n\n4 dp column gap \n**Above the 225 dp breakpoint**\n\n6 dp column gap\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n### **Three column layout**\n\n**Below the 225 dp breakpoint**\n\n2 dp column gap \n**Above the 225 dp breakpoint**\n\n6 dp column gap\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e"]]
