| <template> | 
|     <u-popup | 
|         :show="show" | 
|         @close="closeHandler" | 
|     > | 
|         <view class="u-picker"> | 
|             <u-toolbar | 
|                 v-if="showToolbar" | 
|                 :cancelColor="cancelColor" | 
|                 :confirmColor="confirmColor" | 
|                 :cancelText="cancelText" | 
|                 :confirmText="confirmText" | 
|                 :title="title" | 
|                 @cancel="cancel" | 
|                 @confirm="confirm" | 
|             ></u-toolbar> | 
|             <picker-view | 
|                 class="u-picker__view" | 
|                 :indicatorStyle="`height: ${$u.addUnit(itemHeight)}`" | 
|                 :value="innerIndex" | 
|                 :immediateChange="immediateChange" | 
|                 :style="{ | 
|                     height: `${$u.addUnit(visibleItemCount * itemHeight)}` | 
|                 }" | 
|                 @change="changeHandler" | 
|             > | 
|                 <picker-view-column | 
|                     v-for="(item, index) in innerColumns" | 
|                     :key="index" | 
|                     class="u-picker__view__column" | 
|                 > | 
|                     <text | 
|                         v-if="$u.test.array(item)" | 
|                         class="u-picker__view__column__item u-line-1" | 
|                         v-for="(item1, index1) in item" | 
|                         :key="index1" | 
|                         :style="{ | 
|                             height: $u.addUnit(itemHeight), | 
|                             lineHeight: $u.addUnit(itemHeight), | 
|                             fontWeight: index1 === innerIndex[index] ? 'bold' : 'normal', | 
|                             display: 'block' | 
|                         }" | 
|                     >{{ getItemText(item1) }}</text> | 
|                 </picker-view-column> | 
|             </picker-view> | 
|             <view | 
|                 v-if="loading" | 
|                 class="u-picker--loading" | 
|             > | 
|                 <u-loading-icon mode="circle"></u-loading-icon> | 
|             </view> | 
|         </view> | 
|     </u-popup> | 
| </template> | 
|   | 
| <script> | 
| /** | 
|  * u-picker | 
|  * @description 选择器 | 
|  * @property {Boolean}            show                是否显示picker弹窗(默认 false ) | 
|  * @property {Boolean}            showToolbar            是否显示顶部的操作栏(默认 true ) | 
|  * @property {String}            title                顶部标题 | 
|  * @property {Array}            columns                对象数组,设置每一列的数据 | 
|  * @property {Boolean}            loading                是否显示加载中状态(默认 false ) | 
|  * @property {String | Number}    itemHeight            各列中,单个选项的高度(默认 44 ) | 
|  * @property {String}            cancelText            取消按钮的文字(默认 '取消' ) | 
|  * @property {String}            confirmText            确认按钮的文字(默认 '确定' ) | 
|  * @property {String}            cancelColor            取消按钮的颜色(默认 '#909193' ) | 
|  * @property {String}            confirmColor        确认按钮的颜色(默认 '#3c9cff' ) | 
|  * @property {String | Number}    visibleItemCount    每列中可见选项的数量(默认 5 ) | 
|  * @property {String}            keyName                选项对象中,需要展示的属性键名(默认 'text' ) | 
|  * @property {Boolean}            closeOnClickOverlay    是否允许点击遮罩关闭选择器(默认 false ) | 
|  * @property {Array}            defaultIndex        各列的默认索引 | 
|  * @property {Boolean}            immediateChange        是否在手指松开时立即触发change事件(默认 false ) | 
|  * @event {Function} close        关闭选择器时触发 | 
|  * @event {Function} cancel        点击取消按钮触发 | 
|  * @event {Function} change        当选择值变化时触发 | 
|  * @event {Function} confirm    点击确定按钮,返回当前选择的值 | 
|  */ | 
| import props from './props.js'; | 
| export default { | 
|     name: 'u-picker', | 
|     mixins: [uni.$u.mpMixin, uni.$u.mixin, props], | 
|     data() { | 
|         return { | 
|             // 上一次选择的列索引 | 
|             lastIndex: [], | 
|             // 索引值 ,对应picker-view的value | 
|             innerIndex: [], | 
|             // 各列的值 | 
|             innerColumns: [], | 
|             // 上一次的变化列索引 | 
|             columnIndex: 0, | 
|         } | 
|     }, | 
|     watch: { | 
|         // 监听默认索引的变化,重新设置对应的值 | 
|         defaultIndex: { | 
|             immediate: true, | 
|             handler(n) { | 
|                 this.setIndexs(n, true) | 
|             } | 
|         }, | 
|         // 监听columns参数的变化 | 
|         columns: { | 
|             immediate: true, | 
|             handler(n) { | 
|                 this.setColumns(n) | 
|             } | 
|         }, | 
|     }, | 
|     methods: { | 
|         // 获取item需要显示的文字,判别为对象还是文本 | 
|         getItemText(item) { | 
|             if (uni.$u.test.object(item)) { | 
|                 return item[this.keyName] | 
|             } else { | 
|                 return item | 
|             } | 
|         }, | 
|         // 关闭选择器 | 
|         closeHandler() { | 
|             if (this.closeOnClickOverlay) { | 
|                 this.$emit('close') | 
|             } | 
|         }, | 
|         // 点击工具栏的取消按钮 | 
|         cancel() { | 
|             this.$emit('cancel') | 
|         }, | 
|         // 点击工具栏的确定按钮 | 
|         confirm() { | 
|             this.$emit('confirm', { | 
|                 indexs: this.innerIndex, | 
|                 value: this.innerColumns.map((item, index) => item[this.innerIndex[index]]), | 
|                 values: this.innerColumns | 
|             }) | 
|         }, | 
|         // 选择器某一列的数据发生变化时触发 | 
|         changeHandler(e) { | 
|             const { | 
|                 value | 
|             } = e.detail | 
|             let index = 0, | 
|                 columnIndex = 0 | 
|             // 通过对比前后两次的列索引,得出当前变化的是哪一列 | 
|             for (let i = 0; i < value.length; i++) { | 
|                 let item = value[i] | 
|                 if (item !== (this.lastIndex[i] || 0)) { // 把undefined转为合法假值0 | 
|                     // 设置columnIndex为当前变化列的索引 | 
|                     columnIndex = i | 
|                     // index则为变化列中的变化项的索引 | 
|                     index = item | 
|                     break // 终止循环,即使少一次循环,也是性能的提升 | 
|                 } | 
|             } | 
|             this.columnIndex = columnIndex | 
|             const values = this.innerColumns | 
|             // 将当前的各项变化索引,设置为"上一次"的索引变化值 | 
|             this.setLastIndex(value) | 
|             this.setIndexs(value) | 
|   | 
|             this.$emit('change', { | 
|                 // #ifndef MP-WEIXIN || MP-LARK || MP-TOUTIAO | 
|                 // 微信小程序不能传递this,会因为循环引用而报错 | 
|                 picker: this, | 
|                 // #endif | 
|                 value: this.innerColumns.map((item, index) => item[value[index]]), | 
|                 index, | 
|                 indexs: value, | 
|                 // values为当前变化列的数组内容 | 
|                 values, | 
|                 columnIndex | 
|             }) | 
|         }, | 
|         // 设置index索引,此方法可被外部调用设置 | 
|         setIndexs(index, setLastIndex) { | 
|             this.innerIndex = uni.$u.deepClone(index) | 
|             if (setLastIndex) { | 
|                 this.setLastIndex(index) | 
|             } | 
|         }, | 
|         // 记录上一次的各列索引位置 | 
|         setLastIndex(index) { | 
|             // 当能进入此方法,意味着当前设置的各列默认索引,即为“上一次”的选中值,需要记录,是因为changeHandler中 | 
|             // 需要拿前后的变化值进行对比,得出当前发生改变的是哪一列 | 
|             this.lastIndex = uni.$u.deepClone(index) | 
|         }, | 
|         // 设置对应列选项的所有值 | 
|         setColumnValues(columnIndex, values) { | 
|             // 替换innerColumns数组中columnIndex索引的值为values,使用的是数组的splice方法 | 
|             this.innerColumns.splice(columnIndex, 1, values) | 
|             // 替换完成之后将修改列之后的已选值置空 | 
|             this.setLastIndex(this.innerIndex.slice(0,columnIndex)) | 
|             // 拷贝一份原有的innerIndex做临时变量,将大于当前变化列的所有的列的默认索引设置为0 | 
|             let tmpIndex = uni.$u.deepClone(this.innerIndex) | 
|             for (let i = 0; i < this.innerColumns.length; i++) { | 
|                 if (i > this.columnIndex) { | 
|                     tmpIndex[i] = 0 | 
|                 } | 
|             } | 
|             // 一次性赋值,不能单个修改,否则无效 | 
|             this.setIndexs(tmpIndex) | 
|         }, | 
|         // 获取对应列的所有选项 | 
|         getColumnValues(columnIndex) { | 
|             // 进行同步阻塞,因为外部得到change事件之后,可能需要执行setColumnValues更新列的值 | 
|             // 索引如果在外部change的回调中调用getColumnValues的话,可能无法得到变更后的列值,这里进行一定延时,保证值的准确性 | 
|             (async () => { | 
|                 await uni.$u.sleep() | 
|             })() | 
|             return this.innerColumns[columnIndex] | 
|         }, | 
|         // 设置整体各列的columns的值 | 
|         setColumns(columns) { | 
|             this.innerColumns = uni.$u.deepClone(columns) | 
|             // 如果在设置各列数据时,没有被设置默认的各列索引defaultIndex,那么用0去填充它,数组长度为列的数量 | 
|             if (this.innerIndex.length === 0) { | 
|                 this.innerIndex = new Array(columns.length).fill(0) | 
|             } | 
|         }, | 
|         // 获取各列选中值对应的索引 | 
|         getIndexs() { | 
|             return this.innerIndex | 
|         }, | 
|         // 获取各列选中的值 | 
|         getValues() { | 
|             // 进行同步阻塞,因为外部得到change事件之后,可能需要执行setColumnValues更新列的值 | 
|             // 索引如果在外部change的回调中调用getValues的话,可能无法得到变更后的列值,这里进行一定延时,保证值的准确性 | 
|             (async () => { | 
|                 await uni.$u.sleep() | 
|             })() | 
|             return this.innerColumns.map((item, index) => item[this.innerIndex[index]]) | 
|         } | 
|     }, | 
| } | 
| </script> | 
|   | 
| <style lang="scss" scoped> | 
|     @import "../../libs/css/components.scss"; | 
|   | 
|     .u-picker { | 
|         position: relative; | 
|   | 
|         &__view { | 
|   | 
|             &__column { | 
|                 @include flex; | 
|                 flex: 1; | 
|                 justify-content: center; | 
|   | 
|                 &__item { | 
|                     @include flex; | 
|                     justify-content: center; | 
|                     align-items: center; | 
|                     font-size: 16px; | 
|                     text-align: center; | 
|                     /* #ifndef APP-NVUE */ | 
|                     display: block; | 
|                     /* #endif */ | 
|                     color: $u-main-color; | 
|   | 
|                     &--disabled { | 
|                         /* #ifndef APP-NVUE */ | 
|                         cursor: not-allowed; | 
|                         /* #endif */ | 
|                         opacity: 0.35; | 
|                     } | 
|                 } | 
|             } | 
|         } | 
|   | 
|         &--loading { | 
|             position: absolute; | 
|             top: 0; | 
|             right: 0; | 
|             left: 0; | 
|             bottom: 0; | 
|             @include flex; | 
|             justify-content: center; | 
|             align-items: center; | 
|             background-color: rgba(255, 255, 255, 0.87); | 
|             z-index: 1000; | 
|         } | 
|     } | 
| </style> |