feat(DropdownItem): add lazy-render prop (#6454)

src/dropdown-item/index.js

@@ -25,6 +25,10 @@ export default createComponent({
       type: Array,
       default: () => [],
     },
+    lazyRender: {
+      type: Boolean,
+      default: true,
+    },
   },
 
   data() {
@@ -155,8 +159,9 @@ export default createComponent({
             class={bem('content')}
             position={direction === 'down' ? 'top' : 'bottom'}
             duration={this.transition ? duration : 0}
-            closeOnClickOverlay={closeOnClickOverlay}
+            lazyRender={this.lazyRender}
             overlayStyle={{ position: 'absolute' }}
+            closeOnClickOverlay={closeOnClickOverlay}
             onOpen={this.onOpen}
             onClose={this.onClose}
             onOpened={this.onOpened}

src/dropdown-menu/README.md

@@ -128,6 +128,7 @@ Use `active-color` prop to custom active color of the title and options
 | title | Item title | _string_ | Text of selected option |
 | options | Options | _Option[]_ | `[]` |
 | disabled | Whether to disable dropdown item | _boolean_ | `false` |
+| lazy-render `v2.8.5` | Whether to lazy render util opened | _boolean_ | `true` |
 | title-class | Title class | _string_ | - |
 | get-container `v2.2.4` | Return the mount node for menu | _string \| () => Element_ | - |
 

src/dropdown-menu/README.zh-CN.md

@@ -132,6 +132,7 @@ export default {
 | title | 菜单项标题 | _string_ | 当前选中项文字 |
 | options | 选项数组 | _Option[]_ | `[]` |
 | disabled | 是否禁用菜单 | _boolean_ | `false` |
+| lazy-render `v2.8.5` | 是否在首次展开时才渲染菜单内容 | _boolean_ | `true` |
 | title-class | 标题额外类名 | _string_ | - |
 | get-container `v2.2.4` | 指定挂载的节点，[用法示例](#/zh-CN/popup#zhi-ding-gua-zai-wei-zhi) | _string \| () => Element_ | - |