javafx - 单击按钮时在边框窗格中心内设置 Vbox 时出错

Question

我正在设计一个 javafx 应用程序，使用 BorderPane 作为边框窗格内的 Rootlayout，左侧有按钮。单击我需要将边框（rootlayout）中心设置为不同的addprodct.fxml。我想在 BorderPane 中心的单击插入按钮上添加一个 vbox。

我检查了我的 fxml 是否正确加载， System.out.println("view folder: " + RootController.class.getResource("/Views/AddProduct.fxml"));它打印了 fxml 的确切路径。我尝试使用新的 fxml 设置阶段以查看它是否正确加载并且是否正常工作。

        FXMLLoader loader = new FXMLLoader();
        System.out.println("view folder: " + RootController.class.getResource("/Views/AddProduct.fxml"));
        loader.setLocation(RootController.class.getResource( "/Views/AddProduct.fxml"));
        tryvbox = loader.load();
        main.getPrimaryStage().setScene(new Scene(tryvbox));

是的，我知道已经问过同样的问题，但我实施了解决方案，因为这对我的问题没有帮助。 在边框中心加载新的 fxml

JavaFX：如何使用新值更新边框的中心视图

主.java

    package sample;

    import Controllers.RootController;
    import javafx.application.Application;
    import javafx.fxml.FXML;
    import javafx.fxml.FXMLLoader;
    import javafx.scene.Scene;
    import javafx.scene.layout.BorderPane;
    import javafx.stage.Stage;
    import java.io.IOException;


    public class Main extends Application {
        @FXML
        private BorderPane rootLayout;
        private Stage  primaryStage;
        @Override
        public void start(Stage primaryStage) throws Exception{
            this.primaryStage = primaryStage;
            mainwindow();
        }
        public void mainwindow() throws IOException {
            FXMLLoader loader = new FXMLLoader();
            loader.setLocation(getClass().getResource("/Views/Rootlayout.fxml"));
            rootLayout = loader.load();

            RootController rootController = loader.getController();
            rootController.setMain(this);
            Scene scene= new Scene(rootLayout);
            primaryStage.setTitle("Inventory Manager");
            primaryStage.setScene(scene);
            primaryStage.show();
        }
        public BorderPane getRootLayout() {
            return rootLayout;
        }

        public Stage getPrimaryStage() {
            return primaryStage;
        }

        public static void main(String[] args) {
            launch(args);
        }
    }

根控制器.java

package Controllers;

import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.control.Button;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.VBox;
import sample.Main;

import java.io.IOException;

public class RootController {
    @FXML
    private Button rootBtnInsrt;
    @FXML
    private Button rootBtnUpdate;
    @FXML
    private BorderPane rootLayout;
    private Main main;

    public void setMain(Main main) {
        this.main = main;
    }

    @FXML
    void btnInsrtClick(MouseEvent event) {
        FXMLLoader loader = new FXMLLoader();
        loader.setLocation(RootController.class.getResource( "/Views/AddProduct.fxml"));
        try {
            VBox addProduct1 = loader.load();
        } catch (IOException e) {
            e.printStackTrace();
        }

        AddProductController addProductController= loader.getController();
        addProductController.setMain(main);
        main.getRootLayout().setCenter(rootLayout);
    }
}

根布局.fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Menu?>
<?import javafx.scene.control.MenuBar?>
<?import javafx.scene.control.MenuItem?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.layout.BorderPane?>
<?import javafx.scene.layout.VBox?>

<BorderPane fx:id="rootLayout" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="Controllers.RootController">
   <top>
      <MenuBar prefHeight="21.0" prefWidth="600.0" BorderPane.alignment="CENTER">
        <menus>
          <Menu mnemonicParsing="false" text="File">
            <items>
              <MenuItem mnemonicParsing="false" text="Close" />
            </items>
          </Menu>
          <Menu mnemonicParsing="false" text="Edit">
            <items>
              <MenuItem mnemonicParsing="false" text="Delete" />
            </items>
          </Menu>
          <Menu mnemonicParsing="false" text="Help">
            <items>
              <MenuItem mnemonicParsing="false" text="About" />
            </items>
          </Menu>
        </menus>
      </MenuBar>
   </top>
   <bottom>
      <AnchorPane prefHeight="29.0" prefWidth="600.0" style="-fx-background-color: Black;" BorderPane.alignment="CENTER" />
   </bottom>
   <left>
      <VBox alignment="CENTER" prefHeight="345.0" prefWidth="164.0" spacing="20.0" BorderPane.alignment="CENTER">
         <children>
            <Button fx:id="rootBtnInsrt" mnemonicParsing="false" onMouseClicked="#btnInsrtClick" prefHeight="50.0" prefWidth="132.0" text="Insert " />
            <Button fx:id="rootBtnUpdate" mnemonicParsing="false" onMouseClicked="#btnUpdateClick" prefHeight="50.0" prefWidth="135.0" text="Update" />
            <Button mnemonicParsing="false" prefHeight="50.0" prefWidth="158.0" text="View" />
         </children>
         <padding>
            <Insets left="10.0" right="10.0" />
         </padding>
      </VBox>
   </left>
</BorderPane>

添加产品.fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.layout.ColumnConstraints?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.layout.RowConstraints?>
<?import javafx.scene.layout.VBox?>

<VBox fx:id="addproduct" alignment="CENTER" prefHeight="249.0" prefWidth="400.0" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1">
   <children>
      <Label alignment="CENTER" text="Add Product" VBox.vgrow="ALWAYS" />
      <GridPane VBox.vgrow="ALWAYS">
         <columnConstraints>
            <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" />
            <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" />
         </columnConstraints>
         <rowConstraints>
            <RowConstraints minHeight="10.0" vgrow="SOMETIMES" />
            <RowConstraints minHeight="10.0" vgrow="SOMETIMES" />
            <RowConstraints minHeight="10.0" vgrow="SOMETIMES" />
            <RowConstraints minHeight="10.0" vgrow="SOMETIMES" />
         </rowConstraints>
         <children>
            <Label text="Product Code" />
            <Label text="Product Name :" GridPane.rowIndex="1" />
            <Label text="Product Price :" GridPane.rowIndex="2" />
            <Label text="Product Quantity :" GridPane.rowIndex="3" />
            <TextField GridPane.columnIndex="1" />
            <TextField GridPane.columnIndex="1" GridPane.rowIndex="1" />
            <TextField GridPane.columnIndex="1" GridPane.rowIndex="2" />
            <TextField GridPane.columnIndex="1" GridPane.rowIndex="3" />
         </children>
         <padding>
            <Insets bottom="20.0" left="20.0" right="20.0" top="20.0" />
         </padding>
      </GridPane>
      <HBox alignment="CENTER" spacing="30.0">
         <children>
          <Button alignment="CENTER" maxHeight="40.0" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="ADD" HBox.hgrow="ALWAYS" />
            <Button alignment="CENTER" maxHeight="40.0" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="Reset" HBox.hgrow="ALWAYS" />
            <Button maxHeight="40.0" maxWidth="1.7976931348623157E308" mnemonicParsing="false" text="Back" HBox.hgrow="ALWAYS" />
         </children>
         <padding>
            <Insets bottom="20.0" left="20.0" right="20.0" />
         </padding>
      </HBox>
   </children>
</VBox>

当尝试运行以下代码时出现错误。

1. 线程“JavaFX 应用程序线程”java.lang.RuntimeException 中的异常：java.lang.reflect.InvocationTargetException
2. 引起：java.lang.reflect.InvocationTargetException
3. 引起：java.lang.NullPointerException

都在同一个错误窗格中，这是我的目录结构。 目录结构

标签： javafxjavafx-2borderpane

Answer 1

所以基本上在所有的工作和帮助之后，由于 Try/Catch 块出现了问题。

FXMLLoader loader = new FXMLLoader();
loader.setLocation(RootController.class.getResource( "/Views/AddProduct.fxml"));
    try {
        VBox addProduct1 = loader.load();
    } 
    catch (IOException e) {
        e.printStackTrace();
    }

我删除了 try/catch 并在方法中添加了异常，即void btnInsrtClick(MouseEvent event) throws IOException