[new feature] DropdownMenu: add overlay prop

packages/dropdown-item/index.js

@@ -65,6 +65,7 @@ export default sfc({
           position="top"
           duration={0.2}
           class={bem('content')}
+          overlay={this.parent.overlay}
           overlayStyle={{ position: 'absolute' }}
         >
           {Options}

packages/dropdown-menu/en-US.md

@@ -82,6 +82,7 @@ export default {
 |------|------|------|------|------|
 | active-color | Active color of title and option | `String` | `#1989fa` |
 | z-index | z-index of menu item | `Number` | `10` |
+| overlay | Whether to show overlay | `Boolean` | `true` |
 
 ### DropdownItem Props
 

packages/dropdown-menu/index.js

@@ -8,6 +8,10 @@ export default sfc({
   mixins: [ParentMixin('vanDropdownMenu')],
 
   props: {
+    overlay: {
+      type: Boolean,
+      default: true
+    },
     zIndex: {
       type: Number,
       default: 10

packages/dropdown-menu/zh-CN.md

@@ -84,6 +84,7 @@ export default {
 |------|------|------|------|------|
 | active-color | 菜单标题和选项的选中态颜色 | `String` | `#1989fa` | - |
 | z-index | 菜单栏 z-index 层级 | `Number` | `10` | - |
+| overlay | 是否显示遮罩层 | `Boolean` | `true` | - | - |
 
 ### DropdownItem Props