fix(picker): clear selected value and options when columns is emptied

- Fixed issue where selected value and picker options were not cleared when columns became empty
- Updated wd-picker to reset pickerValue and showValue when columns is empty
- Updated wd-picker-view to clear formatColumns and selectedIndex when columns is empty
- Enhanced selectWithValue to handle empty columns case
- Resolves #935

Closes: #935

Author: TL

src/uni_modules/wot-design-uni/components/wd-picker-view/wd-picker-view.vue

@@ -58,8 +58,14 @@ const selectedIndex = ref<Array<number>>([]) // 格式化之后，每列选中
 watch(
   [() => props.modelValue, () => props.columns],
   (newValue, oldValue) => {
-    if (!isEqual(oldValue[1], newValue[1]) && isArray(newValue[1]) && newValue[1].length > 0) {
-      formatColumns.value = formatArray(newValue[1], props.valueKey, props.labelKey)
+    if (!isEqual(oldValue[1], newValue[1])) {
+      if (isArray(newValue[1]) && newValue[1].length > 0) {
+        formatColumns.value = formatArray(newValue[1], props.valueKey, props.labelKey)
+      } else {
+        // 当 columns 变为空时，清空 formatColumns 和 selectedIndex
+        formatColumns.value = []
+        selectedIndex.value = []
+      }
     }
     if (isDef(newValue[0])) {
       selectWithValue(newValue[0])
@@ -79,7 +85,10 @@ const { proxy } = getCurrentInstance() as any
  * @param {String|Number|Boolean|Array<String|Number|Boolean|Array<any>>}value
  */
 function selectWithValue(value: string | number | boolean | number[] | string[] | boolean[]) {
-  if (formatColumns.value.length === 0) return
+  if (formatColumns.value.length === 0) {
+    selectedIndex.value = [] // 如果列为空，直接清空选中索引
+    return
+  }
   // 使其默认选中首项
   if (value === '' || !isDef(value) || (isArray(value) && value.length === 0)) {
     value = formatColumns.value.map((col) => {

src/uni_modules/wot-design-uni/components/wd-picker/wd-picker.vue

@@ -152,8 +152,14 @@ watch(
   (newValue) => {
     displayColumns.value = deepClone(newValue)
     resetColumns.value = deepClone(newValue)
-    // 获取初始选中项,并展示初始选中文案
-    handleShowValueUpdate(props.modelValue)
+    if (newValue.length === 0) {
+      // 当 columns 变为空时，清空 pickerValue 和 showValue
+      pickerValue.value = isArray(props.modelValue) ? [] : ''
+      showValue.value = ''
+    } else {
+      // 非空时正常更新显示值
+      handleShowValueUpdate(props.modelValue)
+    }
   },
   {
     deep: true,