fix the code example

Signed-off-by: Nliujinwei <hw.liujinwei@huawei.com>
Change-Id: I0580e9d48838f55c5184ba3e2e558575c3c6e9a4

zh-cn/application-dev/reference/arkui-ts/ts-methods-menu.md

@@ -26,25 +26,36 @@
 struct Index {
   @Builder MenuBuilder() {
     Flex({ direction: FlexDirection.Column, alignItems: ItemAlign.Center, justifyContent: FlexAlign.Center }) {
-      Text('close')
-        .fontSize(30)
-        .fontWeight(FontWeight.Bold)
-        .onClick(() => {
-          ContextMenu.close();
-        })
-    }.height(400)
-    .backgroundColor(Color.Pink)
-
+      Button('Test ContextMenu1')
+      Divider().strokeWidth(2).margin(5)
+      Button('Test ContextMenu2')
+      Divider().strokeWidth(2).margin(5)
+      Button('Test ContextMenu3')
+    }
+    .width(200)
+    .height(160)
   }
 
   build() {
-    Flex({ direction: FlexDirection.Column, alignItems: ItemAlign.Start, justifyContent: FlexAlign.Start }) {
+    Flex({ direction: FlexDirection.Column, alignItems: ItemAlign.Center, justifyContent: FlexAlign.Center }) {
       Column() {
-        Text("Text")
-      }.bindContextMenu(this.MenuBuilder, ResponseType.LongPress)
+        Text("Test ContextMenu")
+          .fontSize(20)
+          .width('100%')
+          .height(500)
+          .backgroundColor(0xAFEEEE)
+          .textAlign(TextAlign.Center)
+      }
+      .bindContextMenu(this.MenuBuilder, ResponseType.LongPress)
+      .onDragStart(()=>{
+        // 拖拽时关闭菜单
+        ContextMenu.close();
+      })
     }
     .width('100%')
     .height('100%')
   }
 }
 ```
+
+![contextmenu_close.gif](figures/contextmenu_close.gif)
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