fix(dropdown): set padding of List in the Dropdown to be zero (#1559)

Co-authored-by: maxin <maxin@growingio.com>

src/dropdown/Dropdown.tsx

@@ -40,6 +40,15 @@ export function Dropdown<T = HTMLElement>(props: DropdownProps, ref: React.Forwa
     });
   };
 
+  const withoutPadding = (contentNode: DropdownProps['content']) => {
+    if (React.isValidElement(contentNode)) {
+      return React.cloneElement(contentNode, {
+        className: classnames(`${prefixCls}-p-0`, contentNode.props.className),
+      });
+    }
+    return contentNode;
+  };
+
   const withOnClick = (contentNode: DropdownProps['content']) => {
     const close = () => {
       setControlledVisible(false);
@@ -67,7 +76,7 @@ export function Dropdown<T = HTMLElement>(props: DropdownProps, ref: React.Forwa
       arrowPointAtCenter
       placement={placement}
       visible={controlledVisible}
-      content={withOnClick(content)}
+      content={withOnClick(withoutPadding(content))}
       overlayClassName={classnames(prefixCls, overlayClassName)}
       onVisibleChange={(changedVisible) => {
         setControlledVisible(changedVisible);

src/dropdown/demos/Dropdown.stories.tsx

@@ -40,7 +40,7 @@ export const Demo = () => (
     <h3>Use Case -1看板中“更多”按钮</h3>
     <Dropdown
       content={
-        <List style={{ padding: 0 }}>
+        <List>
           <Item prefix={<ReloadOutlined size="14px" />} value="1">
             刷新数据
           </Item>
@@ -77,7 +77,7 @@ export const Demo = () => (
     <h3>Use Case -2列表/卡片中的操作菜单</h3>
     <Dropdown
       content={
-        <List style={{ padding: 0 }}>
+        <List>
           <Item prefix={<ReloadOutlined size="14px" />} value="1">
             添加到看板
           </Item>
@@ -100,7 +100,7 @@ const Template: Story<DropdownProps> = (args) => <Dropdown {...args} />;
 export const Default = Template.bind({});
 Default.args = {
   content: (
-    <List style={{ padding: 0 }}>
+    <List>
       <Item prefix={<ReloadOutlined size="14px" />} value="1">
         刷新数据
       </Item>

src/dropdown/style/index.less

@@ -7,6 +7,9 @@
   padding: 8px;
   overflow: visible;
   background-color: @gray-0;
+  &-p-0 {
+    padding: 0;
+  }
   .border(4);
   .elevation(2);
 }