从另一个控制器JavaFX更改标签文本

Question

我从另一个控制器更改标签时遇到了一些麻烦，这里是我的项目的结构，我有一个带有tableview的OverviewController类，所以我想使用在那个中选择的对象tableview，因为我从OverviewController中的按钮打开另一个窗口，我决定使用句柄来创建舞台，以及这样的一切：

public class EditarFilmeController {

    @FXML
    private CheckBox is3D;

    @FXML
    private JFXTextField tituloField;

    @FXML
    private JFXTextField categoriaField;

    @FXML
    private JFXTextField protagonistaField;

    @FXML
    private JFXTextField duracaoField;

    @FXML
    private JFXTextField diretorField;

    @FXML
    private JFXTextField capacidadeField;

    @FXML
    private JFXTextField classificacaoField;

    @FXML
    private JFXTextField salaField;

    private Stage dialogStage;
    private Filmes filme;
    private boolean clicado = false;

    @FXML
    private void initialize() {

    }

    public void setDialogStage(Stage dialogStage) {
        this.dialogStage = dialogStage;

    }

    public void setFilme(Filmes filme) {
        this.filme = filme;
        tituloField.setText(filme.getNome());
        categoriaField.setText(filme.getCategoria());
        protagonistaField.setText(filme.getProtagonista());
        duracaoField.setText(filme.getDuracao());
        diretorField.setText(filme.getDiretor());
        classificacaoField.setText(filme.getClassificacao());
        salaField.setText(filme.getSalaNumero());
        capacidadeField.setText(Integer.toString(filme.getCapacidade()));

    }

    public boolean clicado() {
        return clicado;
    }

    // se o usuario clicar aceitar:
    @FXML
    private void handleAceitar() {
        if (isInputValido()) {
            filme.setNome(tituloField.getText());
            filme.setCategoria(categoriaField.getText());
            filme.setClassificacao(classificacaoField.getText());
            filme.setProtagonista(protagonistaField.getText());
            filme.setDuracao(duracaoField.getText());
            filme.setDiretor(diretorField.getText());
            filme.setSala(salaField.getText());
            clicado = true;
            dialogStage.close();
        }
    }
    @FXML
    void handle3D(ActionEvent event) {
        filme.set3D(is3D.isSelected());
    }
    public boolean getis3D() {
        return is3D.isSelected();
    }
    @FXML
    private void handleCancelar() {
        dialogStage.close();
    }

    private boolean isInputValido() {
        String mensagemErro = "";

        if (tituloField.getText() == null || tituloField.getText().length() == 0) {
            mensagemErro += "Titulo invalido ou vazio!\n";
        }
        if (categoriaField.getText() == null || categoriaField.getText().length() == 0) {
            mensagemErro += "Categoria invalida ou vazia!\n";
        }
        if (classificacaoField.getText() == null || classificacaoField.getText().length() == 0) {
            mensagemErro += "Classificacao invalida ou vazia!\n";
        }

        if (protagonistaField.getText() == null || protagonistaField.getText().length() == 0) {
            mensagemErro += "Protagonista invalido ou vazio!\n";
        }
        if (duracaoField.getText() == null || duracaoField.getText().length() == 0) {
            mensagemErro += "Duracao invalido ou vazio!\n";
        }
        if (diretorField.getText() == null || diretorField.getText().length() == 0) {
            mensagemErro += "Diretor invalido ou vazio!\n";
        }
        if (mensagemErro.length() == 0) {
            return true;
        } else {
            Alert alerta = new Alert(AlertType.WARNING);
            alerta.initOwner(dialogStage);
            alerta.setHeaderText("Por favor corrija as informações");
            alerta.setTitle("Informação inválida");
            alerta.setContentText(mensagemErro);
            alerta.showAndWait();
            return false;
        }
    }
}

问题是我想根据在tableview（filmeSelecionado）中选择的内容在控制器上设置标签，我无法在stackoverflow上找到解决方案，因为关于这个问题的另一个问题是＆n＆与我的问题相同，我尝试使用venderIngressoController.setCategoria(filmeSelecionado.getCategoria()); 正如你在代码中看到的，但是它给了我一个nullException，这是另一个类中的setCategoria：

public void setCategoria (String nome) {
        categoriaLabel.setText(nome);
    }

我无法找到改变标签文字的方法，而不会让我感觉不舒服。有谁知道如何解决这一问题？谢谢！

编辑：

package projeto.resources;

import com.jfoenix.controls.JFXButton;
import com.jfoenix.controls.JFXTextField;

import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.control.CheckBox;
import javafx.scene.control.Label;
import javafx.stage.Stage;
import projeto.Filmes;

public class VenderIngressoController {
    @FXML
    private Label tituloLabel;

    @FXML
    private Label salaLabel;

    @FXML
    private Label categoriaLabel;

    @FXML
    private Label diretorLabel;

    @FXML
    private Label duracaoLabel;

    @FXML
    private Label protagonistaLabel;

    @FXML
    private Label classificacaoLabel;

    @FXML
    private Label e3dLabel;

    @FXML
    private JFXButton gerarIngresso;

    @FXML
    private JFXButton cancelarIngresso;

    @FXML
    private CheckBox meiaEntradaBox;

    @FXML
    private JFXTextField precoEspecialField;

    @FXML
    private CheckBox checkPrecoEspecial;

    private Filmes filme;

    private Stage dialogStage;
    private int precoEspecial;

    public int getPrecoEspecial() {
        return precoEspecial;
    }
    public void setPrecoEspecial(int precoEspecial) {
        this.precoEspecial = precoEspecial;
    }
    public int getPreco() {
        return preco;
    }
    public void setPreco(int preco) {
        this.preco = preco;
    }
    public int getMeiaEntrada() {
        return meiaEntrada;
    }
    public void setMeiaEntrada(int meiaEntrada) {
        this.meiaEntrada = meiaEntrada;
    }

    private int preco;
    private int meiaEntrada;


    @FXML
    private void initialize() {

    }
    public void setDialogStage(Stage dialogStage) {
        this.dialogStage = dialogStage;

    }

    public void VenderIngresso(Filmes filme) {
        this.filme = filme;
        tituloLabel.setText(filme.getNome());
        salaLabel.setText(filme.getSalaNumero());
        categoriaLabel.setText(filme.getCategoria());
        diretorLabel.setText(filme.getDiretor());
        duracaoLabel.setText(filme.getDuracao());
        protagonistaLabel.setText(filme.getProtagonista());
        classificacaoLabel.setText(filme.getClassificacao());
        if (filme.get3D() == true) {
            e3dLabel.setText("Sim");
        } else {
            e3dLabel.setText("Não");
        }

    }
    public void setCategoria (String nome) {
        categoriaLabel.setText(nome);
    }
    @FXML
    void handleCancelarIngresso(ActionEvent event) {
        dialogStage.close();
    }

    @FXML
    void handleGerarIngresso(ActionEvent event) {

    }

}

错误StackTrace：

Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
    at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1774)
    at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
    at javafx.event.Event.fireEvent(Event.java:198)
    at javafx.scene.Node.fireEvent(Node.java:8413)
    at javafx.scene.control.Button.fire(Button.java:185)
    at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
    at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
    at javafx.event.Event.fireEvent(Event.java:198)
    at javafx.scene.Scene$MouseHandler.process(Scene.java:3757)
    at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
    at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
    at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:394)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$353(GlassViewEventHandler.java:432)
    at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:431)
    at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
    at com.sun.glass.ui.View.notifyMouse(View.java:937)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.lambda$null$147(WinApplication.java:177)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
    at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
    at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1771)
    ... 52 more
Caused by: java.lang.NullPointerException
    at projeto.resources.EditarFilmeController.setFilme(EditarFilmeController.java:65)
    at projeto.MainApp.showEditarFilmeDialog(MainApp.java:105)
    at projeto.resources.FilmeOverviewController.handleEditarFilme(FilmeOverviewController.java:145)
    ... 62 more