fix 点击空 置空curtextitem'

src/components/editClass/edit/items/SBaseIconTextEdit.ts

@@ -397,13 +397,13 @@ export class SBaseIconTextEdit extends SGraphEdit {
      * @return  是否处理事件
     */
     onMouseDown(event: SMouseEvent): boolean {
+        this.curTextItem = null;
         if (this.status == SItemStatus.Normal) {
             super.onMouseDown(event)
             return true;
         } else if (this.status == SItemStatus.Edit) {
             return super.onMouseDown(event);
         }
-
         return true;
     } // Function onMouseDown()