fix: MainPage.ets, 国殇代码容错处理

@@ -44,13 +44,15 @@ struct MainPage {
     })
 
     let dataModelStr : string = SPHelper.default.getSync(SpConstants.APP_LAUNCH_PAGE_DATA_MODEL,'') as string
-    let dataModel : LaunchDataModel = JSON.parse(dataModelStr)
-    console.log(dataModelStr)
-    // 处理国殇模式数据
-    let mourns: mournsInfoModel = dataModel.mourns as mournsInfoModel
-    let GrayManage = new GrayManageModel()
-    GrayManage.setMourning(mourns)
-    AppStorage.setOrCreate('GrayManage', GrayManage)
+    if (dataModelStr) {
+      let dataModel : LaunchDataModel = JSON.parse(dataModelStr)
+      console.log(dataModelStr)
+      // 处理国殇模式数据
+      let mourns: mournsInfoModel = dataModel.mourns as mournsInfoModel
+      let GrayManage = new GrayManageModel()
+      GrayManage.setMourning(mourns)
+      AppStorage.setOrCreate('GrayManage', GrayManage)
+    }
   }
 
   pageTransition() {