Pull request #1821: 无JIRA任务 补充类型

Merge in VISUAL/fineui from ~TELLER/fineui:bugfix to master

* commit '582fb7629af5b65810478821fe862574da43e226':
  chore: 补充类型

typescript/base/single/button/button.basic.ts

@@ -3,6 +3,8 @@ import { Single } from "../single";
 export declare class BasicButton extends Single {
     static EVENT_CHANGE: string;
 
+    static xtype: string;
+
     _createShadow(): void;
 
     bindEvent(): void;