当前位置： 文江博客话题详情

JAVAFX- tableView的问题（NullPoInterException）

发布于 2025-01-23 19:42:10 字数 10563 浏览 1 评论 0原文

我在Javafx中的TableView Control遇到了一个巨大的问题。那是我第一次使用它，我不知道我在做什么错。

我的代码：

主类：

package sample;

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception{
        Parent root = FXMLLoader.load(getClass().getResource("sample.fxml"));
        primaryStage.setTitle("Hello World");
        primaryStage.setScene(new Scene(root, 300, 275));
        primaryStage.show();
    }
    
    public static void main(String[] args) {
        launch(args);
    }
}

控制器类：

package sample;

import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.TableView;
import javafx.stage.Modality;
import javafx.stage.Stage;

import java.io.IOException;

public class Controller {

    @FXML
    private TableView<Person> peopleTableView;

    @FXML
    public void openNewWindow(){
        try {
            Parent root = FXMLLoader.load(getClass().getResource("mainWindow.fxml"));
            Stage mainWindow = new Stage();
            mainWindow.setTitle("App");
            mainWindow.setScene(new Scene(root, 1200, 600));
            mainWindow.initModality(Modality.APPLICATION_MODAL);
            mainWindow.show();

            ObservableList<Person> people = FXCollections.observableArrayList();

            people.add(new Person("Walter", "White"));
            people.add(new Person("Gus", "Fring"));

            peopleTableView.setItems(people);
        }
        catch (IOException e) {
            e.printStackTrace();
        }
    }
}

类别：

package sample;

import javafx.beans.property.SimpleStringProperty;

public class Person {

    private SimpleStringProperty firstName = new SimpleStringProperty("");
    private SimpleStringProperty lastName = new SimpleStringProperty("");

    public Person(String firstName, String lastName) {
        this.firstName.set(firstName);
        this.lastName.set(lastName);
    }

    public String getFirstName() {
        return firstName.get();
    }

    public SimpleStringProperty firstNameProperty() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName.set(firstName);
    }

    public String getLastName() {
        return lastName.get();
    }

    public SimpleStringProperty lastNameProperty() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName.set(lastName);
    }
}

和两个FXMLS代码，一个用于运行代码时显示的窗口：

sample.fxml：

<?import javafx.scene.control.Button?>
<?import javafx.scene.layout.BorderPane?>
<BorderPane fx:controller="sample.Controller"
            xmlns:fx="http://javafx.com/fxml">
    <center>
        <Button fx:id="openWindowButton" text="Open new window" onAction="#openNewWindow"/>
    </center>
</BorderPane>

一个用于tableView的新阶段：

：

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

<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>

<?import javafx.scene.control.cell.PropertyValueFactory?>
<BorderPane xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.Controller">
    <center>
        <TableView fx:id="peopleTableView">
            <columns>
                <TableColumn text="First Name">
                    <cellValueFactory>
                        <PropertyValueFactory property="firstName"/>
                    </cellValueFactory>
                </TableColumn>
                <TableColumn text="Last Name">
                    <cellValueFactory>
                        <PropertyValueFactory property="lastName"/>
                    </cellValueFactory>
                </TableColumn>
            </columns>
        </TableView>
    </center>
</BorderPane>

mainwindow.fxml 是 - 我无法设置TableView的项目，因为我会发现它是无效的，即使它清楚地显示在新阶段（我相信）它实际上存在。

错误代码：

Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
    at javafx.fxml/javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1787)
    at javafx.fxml/javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1670)
    at javafx.base/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
    at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at javafx.base/com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at javafx.base/com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
    at javafx.base/javafx.event.Event.fireEvent(Event.java:198)
    at javafx.graphics/javafx.scene.Node.fireEvent(Node.java:8879)
    at javafx.controls/javafx.scene.control.Button.fire(Button.java:200)
    at javafx.controls/com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:206)
    at javafx.controls/com.sun.javafx.scene.control.inputmap.InputMap.handle(InputMap.java:274)
    at javafx.base/com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
    at javafx.base/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
    at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at javafx.base/com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at javafx.base/com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
    at javafx.base/javafx.event.Event.fireEvent(Event.java:198)
    at javafx.graphics/javafx.scene.Scene$MouseHandler.process(Scene.java:3851)
    at javafx.graphics/javafx.scene.Scene$MouseHandler.access$1200(Scene.java:3579)
    at javafx.graphics/javafx.scene.Scene.processMouseEvent(Scene.java:1849)
    at javafx.graphics/javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2588)
    at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:397)
    at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
    at java.base/java.security.AccessController.doPrivileged(Native Method)
    at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$2(GlassViewEventHandler.java:434)
    at javafx.graphics/com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:390)
    at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:433)
    at javafx.graphics/com.sun.glass.ui.View.handleMouseEvent(View.java:556)
    at javafx.graphics/com.sun.glass.ui.View.notifyMouse(View.java:942)
    at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:174)
    at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: java.lang.reflect.InvocationTargetException
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at com.sun.javafx.reflect.Trampoline.invoke(MethodUtil.java:76)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at javafx.base/com.sun.javafx.reflect.MethodUtil.invoke(MethodUtil.java:273)
    at javafx.fxml/com.sun.javafx.fxml.MethodHelper.invoke(MethodHelper.java:83)
    at javafx.fxml/javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1784)
    ... 47 more
Caused by: java.lang.NullPointerException
    at TableView.issue/sample.Controller.openNewWindow(Controller.java:35)
    ... 59 more
原文

I am having a huge problem with TableView control in JavaFX. That's the first time I'm ever using it and I don't know what am I doing wrong.

My code:

Main class:

package sample;

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception{
        Parent root = FXMLLoader.load(getClass().getResource("sample.fxml"));
        primaryStage.setTitle("Hello World");
        primaryStage.setScene(new Scene(root, 300, 275));
        primaryStage.show();
    }
    
    public static void main(String[] args) {
        launch(args);
    }
}

Controller class:

package sample;

import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.TableView;
import javafx.stage.Modality;
import javafx.stage.Stage;

import java.io.IOException;

public class Controller {

    @FXML
    private TableView<Person> peopleTableView;

    @FXML
    public void openNewWindow(){
        try {
            Parent root = FXMLLoader.load(getClass().getResource("mainWindow.fxml"));
            Stage mainWindow = new Stage();
            mainWindow.setTitle("App");
            mainWindow.setScene(new Scene(root, 1200, 600));
            mainWindow.initModality(Modality.APPLICATION_MODAL);
            mainWindow.show();

            ObservableList<Person> people = FXCollections.observableArrayList();

            people.add(new Person("Walter", "White"));
            people.add(new Person("Gus", "Fring"));

            peopleTableView.setItems(people);
        }
        catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Person class:

package sample;

import javafx.beans.property.SimpleStringProperty;

public class Person {

    private SimpleStringProperty firstName = new SimpleStringProperty("");
    private SimpleStringProperty lastName = new SimpleStringProperty("");

    public Person(String firstName, String lastName) {
        this.firstName.set(firstName);
        this.lastName.set(lastName);
    }

    public String getFirstName() {
        return firstName.get();
    }

    public SimpleStringProperty firstNameProperty() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName.set(firstName);
    }

    public String getLastName() {
        return lastName.get();
    }

    public SimpleStringProperty lastNameProperty() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName.set(lastName);
    }
}

And two FXMLs codes, one for the window that shows up when we run the code:

sample.fxml:

<?import javafx.scene.control.Button?>
<?import javafx.scene.layout.BorderPane?>
<BorderPane fx:controller="sample.Controller"
            xmlns:fx="http://javafx.com/fxml">
    <center>
        <Button fx:id="openWindowButton" text="Open new window" onAction="#openNewWindow"/>
    </center>
</BorderPane>

And one for the new stage with TableView:

mainWindow.fxml:

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

<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>

<?import javafx.scene.control.cell.PropertyValueFactory?>
<BorderPane xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.Controller">
    <center>
        <TableView fx:id="peopleTableView">
            <columns>
                <TableColumn text="First Name">
                    <cellValueFactory>
                        <PropertyValueFactory property="firstName"/>
                    </cellValueFactory>
                </TableColumn>
                <TableColumn text="Last Name">
                    <cellValueFactory>
                        <PropertyValueFactory property="lastName"/>
                    </cellValueFactory>
                </TableColumn>
            </columns>
        </TableView>
    </center>
</BorderPane>

So the issue is - I can't set items of TableView, because I get an exception that it is null even though it clearly shows up in the new stage which (I believe) it actually exists.

Error code:

Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
    at javafx.fxml/javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1787)
    at javafx.fxml/javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1670)
    at javafx.base/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
    at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at javafx.base/com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at javafx.base/com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
    at javafx.base/javafx.event.Event.fireEvent(Event.java:198)
    at javafx.graphics/javafx.scene.Node.fireEvent(Node.java:8879)
    at javafx.controls/javafx.scene.control.Button.fire(Button.java:200)
    at javafx.controls/com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:206)
    at javafx.controls/com.sun.javafx.scene.control.inputmap.InputMap.handle(InputMap.java:274)
    at javafx.base/com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
    at javafx.base/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
    at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at javafx.base/com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at javafx.base/com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
    at javafx.base/javafx.event.Event.fireEvent(Event.java:198)
    at javafx.graphics/javafx.scene.Scene$MouseHandler.process(Scene.java:3851)
    at javafx.graphics/javafx.scene.Scene$MouseHandler.access$1200(Scene.java:3579)
    at javafx.graphics/javafx.scene.Scene.processMouseEvent(Scene.java:1849)
    at javafx.graphics/javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2588)
    at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:397)
    at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
    at java.base/java.security.AccessController.doPrivileged(Native Method)
    at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$2(GlassViewEventHandler.java:434)
    at javafx.graphics/com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:390)
    at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:433)
    at javafx.graphics/com.sun.glass.ui.View.handleMouseEvent(View.java:556)
    at javafx.graphics/com.sun.glass.ui.View.notifyMouse(View.java:942)
    at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:174)
    at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: java.lang.reflect.InvocationTargetException
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at com.sun.javafx.reflect.Trampoline.invoke(MethodUtil.java:76)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at javafx.base/com.sun.javafx.reflect.MethodUtil.invoke(MethodUtil.java:273)
    at javafx.fxml/com.sun.javafx.fxml.MethodHelper.invoke(MethodHelper.java:83)
    at javafx.fxml/javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1784)
    ... 47 more
Caused by: java.lang.NullPointerException
    at TableView.issue/sample.Controller.openNewWindow(Controller.java:35)
    ... 59 more

如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

扫码二维码加入Web技术交流群

发布评论

需要 登录 才能够评论， 你可以免费 注册 一个本站的账号。

评论（1）

静若繁花 2025-01-30 19:42:10

问题是您正在尝试将两个FXML文件使用相同的控制器类使用（我认为这意味着您两次都有相同的控制器实例，情况并非如此）。

OpenNewWindow（）方法在Controller实例上调用，该实例是在加载sample.fxml时创建的。该fxml文件没有名为peopletableView的字段，因此peopletableView在该实例中为null，peopletableview.setitems（...）空指针异常。

peopletableView字段在Controller实例中初始化，该实例是在加载mainwindow.fxml时创建的，但是在该实例上未调用任何方法。

解决方案是为每个FXML文件使用其他控制器类（您基本上应该始终执行此操作）。您可以在控制器中使用initialize（）方法mainwindow.fxml来初始化表数据。

这是sample.fxml的控制器：

public class LoginController {

    @FXML
    public void openNewWindow(){
        try {
            Parent root = FXMLLoader.load(getClass().getResource("mainWindow.fxml"));
            Stage mainWindow = new Stage();
            mainWindow.setTitle("App");
            mainWindow.setScene(new Scene(root, 1200, 600));
            mainWindow.initModality(Modality.APPLICATION_MODAL);
            mainWindow.show();

        }
        catch (IOException e) {
            e.printStackTrace();
        }
    }
}

这是mainwindow.fxml的控制器：

public class MainController {

    @FXML
    private TableView<Person> peopleTableView ;

    @FXML
    private void initialize() {
        ObservableList<Person> people = FXCollections.observableArrayList();

        people.add(new Person("Walter", "White"));
        people.add(new Person("Gus", "Fring"));


        peopleTableView.setItems(people);
    }
}

现在只需更新两个FXML文件中的fx：Controller属性。

如果您需要将数据从一个控制器传递到下一个，请参见传递参数Javafx fxml

例如，如果您想将表数据加载到第一个控制器的opennewwindow（）方法（这似乎是不自然的，但将作为一个示例），您可以

public class LoginController {

    @FXML
    public void openNewWindow(){
        try {

            // Note using FXMLLoader instance, not static load(URL) method:
            FXMLLoader loader = new FXMLLoader(getClass().getResource("mainWindow.fxml"));
            Parent root = loader.load();

            Stage mainWindow = new Stage();
            mainWindow.setTitle("App");
            mainWindow.setScene(new Scene(root, 1200, 600));
            mainWindow.initModality(Modality.APPLICATION_MODAL);
            mainWindow.show();

            ObservableList<Person> people = FXCollections.observableArrayList();

            people.add(new Person("Walter", "White"));
            people.add(new Person("Gus", "Fring"));

            MainController mainController = loader.getController();
            mainController.initializeTableData(people);

        }
        catch (IOException e) {
            e.printStackTrace();
        }
    }
}

：

public class MainController {

    @FXML
    private TableView<Person> peopleTableView ;

    public void initializeTableData(ObservableList<Person> people) {

        peopleTableView.setItems(people);
    }
}

做 在控制器之间进行交流的各种方式，请参见传递参数Javafx fxml

The problem is you're trying to use the same controller class for both FXML files (I think, assuming that this means you'll have the same controller instance both times, which is not the case).

The openNewWindow() method is called on the Controller instance that is created when you load sample.fxml. That FXML file has no field called peopleTableView, so peopleTableView is null in that instance, and peopleTableView.setItems(...) results in a null pointer exception.

The peopleTableView field is initialized in the Controller instance that is created when you load mainWindow.fxml, but no methods are called on that instance.

The solution is to use a different controller class for each FXML file (you should basically always do this). You can use the initialize() method in the controller for mainWindow.fxml to initialize the table data.

Here's the controller for sample.fxml:

public class LoginController {

    @FXML
    public void openNewWindow(){
        try {
            Parent root = FXMLLoader.load(getClass().getResource("mainWindow.fxml"));
            Stage mainWindow = new Stage();
            mainWindow.setTitle("App");
            mainWindow.setScene(new Scene(root, 1200, 600));
            mainWindow.initModality(Modality.APPLICATION_MODAL);
            mainWindow.show();

        }
        catch (IOException e) {
            e.printStackTrace();
        }
    }
}

And here's the controller for mainWindow.fxml:

public class MainController {

    @FXML
    private TableView<Person> peopleTableView ;

    @FXML
    private void initialize() {
        ObservableList<Person> people = FXCollections.observableArrayList();

        people.add(new Person("Walter", "White"));
        people.add(new Person("Gus", "Fring"));


        peopleTableView.setItems(people);
    }
}

Now just update the fx:controller attributes in both FXML files.

If you need to pass data from one controller to the next, see Passing Parameters JavaFX FXML

For example, if you wanted to load the table data in the first controller's openNewWindow() method (which seems unnatural, but will serve as an example), you could do:

public class LoginController {

    @FXML
    public void openNewWindow(){
        try {

            // Note using FXMLLoader instance, not static load(URL) method:
            FXMLLoader loader = new FXMLLoader(getClass().getResource("mainWindow.fxml"));
            Parent root = loader.load();

            Stage mainWindow = new Stage();
            mainWindow.setTitle("App");
            mainWindow.setScene(new Scene(root, 1200, 600));
            mainWindow.initModality(Modality.APPLICATION_MODAL);
            mainWindow.show();

            ObservableList<Person> people = FXCollections.observableArrayList();

            people.add(new Person("Walter", "White"));
            people.add(new Person("Gus", "Fring"));

            MainController mainController = loader.getController();
            mainController.initializeTableData(people);

        }
        catch (IOException e) {
            e.printStackTrace();
        }
    }
}

and

public class MainController {

    @FXML
    private TableView<Person> peopleTableView ;

    public void initializeTableData(ObservableList<Person> people) {

        peopleTableView.setItems(people);
    }
}

But again, for a full discussion of the various ways to communicate between controllers, see Passing Parameters JavaFX FXML

回复 原文
~没有更多了~

关于作者

爱冒险

暂无简介

文章
评论
26 人气
发私信

相关话题

更多

热门标签

操作系统 程序设计 IT运维 Linux系统管理 JavaScript 服务器应用 solaris C/C++ PHP Shell BSD Vue.js aix Oracle Python HTML 系统管理 HTML5 CSS 前端
更多

推荐作者

李珊平

文章 0 评论 0

Quxin

文章 0 评论 0

范无咎

文章 0 评论 0

github_ZOJ2N8YxBm

文章 0 评论 0

若言

文章 0 评论 0

南…巷孤猫

文章 0 评论 0

更多

友情链接

文江博客
    我们使用 Cookies 和其他技术来定制您的体验包括您的登录状态等。通过阅读我们的 隐私政策 了解更多相关信息。 单击 接受 或继续使用网站，即表示您同意使用 Cookies 和您的相关数据。
    原文