[FC]:解决UISystem 初始化赋值问题

mk_framework/assets/script/mk/system/UISystem.ts

@@ -19,6 +19,12 @@ export default class UISystem extends cc.Component {
     private curOnPanelDic: { [key: string]: cc.Node } = {};
     /** 上一个打开的界面名称 */
     private lastOpenPanelName: string = "";
+    
+    /** onLoad */
+    onLoad() {
+        //自行赋值
+        mk.ui = this;
+    }
 
     /** start */
     start() {
@@ -51,16 +57,16 @@ export default class UISystem extends cc.Component {
                     let node_panel = cc.instantiate(prefab);
                     self.curOnPanelDic[panelName] = node_panel;
 
+                    if (self.panelParent) {
+                        self.panelParent = self.node;
+                    }
+
                     //如果父节点不存在，就默认把该节点定为panel的父节点
                     if (!self.panelParent) {
                         console.error("[UISystem] UI的父节点panelParent为null,请检查脚本挂载情况");
                         return;
                     }
 
-                    if (self.panelParent) {
-                        self.panelParent = self.node;
-                    }
-
                     self.panelParent.addChild(node_panel);
 
                     switch (openAction) {