Pull request #3240: 无JIRA fix(widget.ts): 把_renderEngine改为静态属性

Merge in VISUAL/fineui from ~XAVIER.MENG/fineui:master to master

* commit 'be531e8e2760ecc6ff8b231259f3fd1510731bb5':
  无JIRA fix(widget.ts): 把_renderEngine改为静态属性

typescript/core/widget.ts

@@ -418,6 +418,11 @@ export declare class Widget extends OB {
      */
     static registerRenderEngine(engine: RenderEngine): void;
 
+    /**
+     * 渲染引擎
+     */
+    static _renderEngine: RenderEngine;
+
     /**
      * 出现loading的锁
      */
@@ -476,11 +481,6 @@ export declare class Widget extends OB {
      */
     _manualSetValid: boolean;
 
-    /**
-     * 渲染引擎
-     */
-    _renderEngine: RenderEngine;
-
     _store(): void;
 
     // 生命周期函数