既往史下拉滚动条添加

src/components/SpreadDrop/index.less

@@ -11,7 +11,9 @@
     display: inline-block;
     // width: 200px;
     vertical-align: top;
-    margin-left: 8px;   
+    margin-left: 8px;
+    max-height: 200px;
+    overflow-y: auto;
   }
   .independent{
     display: block;