更新了中央显示

src/com/student/mathquiz/MainApp.java

@@ -15,22 +15,25 @@ public class MainApp extends Application {
   private Stage primaryStage;
   private BorderPane rootLayout;
 
+  // start 方法修改后
   @Override
   public void start(Stage primaryStage) {
     this.primaryStage = primaryStage;
     this.primaryStage.setTitle("小初高数学学习软件");
-
     initRootLayout();
     showLoginView();
+    this.primaryStage.centerOnScreen();
+    this.primaryStage.show();
   }
 
+
   public void initRootLayout() {
     try {
       FXMLLoader loader = new FXMLLoader(MainApp.class.getResource("view/RootLayout.fxml"));
       rootLayout = loader.load();
       Scene scene = new Scene(rootLayout);
       primaryStage.setScene(scene);
-      primaryStage.show();
+      //primaryStage.show();
     } catch (IOException e) {
       e.printStackTrace();
     }