javafx - JavaFX-在lambda中使用TreeView.EditEvent的参数类型不兼容

Question

在JavaFX TreeView中，我正在使用扩展TreeItem的“自定义”类。这使我能够在TreeView中编辑项目(我可以双击它们并在运行应用程序时编辑内容)，但似乎无法正确设置.setOnEditCommit()方法。我希望它的工作方式类似于表 View 中的功能，但是我还没有运气。

这是我在 Controller 中尝试设置setOnEditCommit()方法的代码。在我称为“trvDivisies”的TreeView中，我显示了橄榄球队的分区/比赛，而在较低一级，我显示了某个分区的所有球队。

private void setUpTreeView() {
    trvDivisies.setEditable(true);
    trvDivisies.setShowRoot(false);

    TreeItem<String> root = new TreeItem<>();

    for (Divisie d : divisies) {
        TreeItem<String> divisieTreeItem = d;
        divisieTreeItem.valueProperty().set(d.getNaam());

        for (VoetbalTeam vt : d.getVoetbalTeams()) {
            TreeItem<String> voetbalTeamTreeItem = vt;
            voetbalTeamTreeItem.valueProperty().setValue(vt.getTeamNaam());
            divisieTreeItem.getChildren().add(voetbalTeamTreeItem);
        }

        root.getChildren().add(divisieTreeItem);
    }

    trvDivisies.setRoot(root);

    trvDivisies.getSelectionModel().selectedItemProperty().addListener(new ChangeListener() {
        @Override
        public void changed(ObservableValue observable, Object oldValue, Object newValue) {
            System.out.println(newValue);
        }
    });

    trvDivisies.setCellFactory(TextFieldTreeCell.forTreeView());
    // I get an error at the following line when compiling
    trvDivisies.setOnEditCommit((TreeView.EditEvent p) -> {
        TreeItem<String> selectedItem = p.getTreeItem();
        if (selectedItem instanceof Divisie) {
            updateDivisie((Divisie)selectedItem);
        } else if (selectedItem instanceof VoetbalTeam) {
            updateTeam((VoetbalTeam)selectedItem);
        }
    });
}

这就是我的“自定义”类的样子。

public class Divisie extends TreeItem<String> {
private static int idCount = 0;

private int id;
private String naam;
private List<VoetbalTeam> voetbalTeams;

public int getId() {
    return id;
}

public String getNaam() {
    return naam;
}

public List<VoetbalTeam> getVoetbalTeams() {
    return voetbalTeams;
}

public Divisie(int id, String naam) {
    super(naam);
    this.id = id;
    this.naam = naam;
}

public Divisie(String naam) {
    this.id = ++idCount;
    this.naam = naam;
}

public void addTeam(VoetbalTeam toBeAdded) {
    if (voetbalTeams == null) {
        voetbalTeams = new LinkedList<>();
    }
    voetbalTeams.add(toBeAdded);
}

@Override
public String toString() {
    return this.naam;
}
}

第二级“下级”

public class VoetbalTeam extends TreeItem<String> {
private static int idCount = 0;

private int id;
private String teamNaam;
private List<Speler> spelers;

public int getId() {
    return id;
}

public String getTeamNaam() {
    return teamNaam;
}

public List<Speler> getSpelers() {
    return this.spelers;
}

public VoetbalTeam(int id, String teamNaam) {
    super(teamNaam);
    this.id = id;
    this.teamNaam = teamNaam;
}

public VoetbalTeam(String teamNaam) {
    super(teamNaam);
    this.id = ++idCount;
    this.teamNaam = teamNaam;
}

public void addSpeler(Speler nieuweSpeler) {
    if (spelers == null) {
        spelers = new LinkedList<>();
    }
    this.spelers.add(nieuweSpeler);
}

@Override
public String toString() {
    return this.teamNaam;
}
}

尝试使用.setOnEditCommit()方法运行应用程序时，出现错误消息:

Error:(97, 37) java: incompatible types: incompatible parameter types in lambda expression

我希望你们能告诉我将TreeView.EditEvent lambda更改为什么，或帮助我找到一个更简单的解决方案。

Answer 1

对于TreeView<T>， setOnEditCommit 的签名为

void setOnEditCommit(EventHandler<TreeView.EditEvent<T>> value)

由于您(显然)有一个 TreeView<String>，因此您需要

trvDivisies.setOnEditCommit((TreeView.EditEvent<String> p) -> {

    // ...

});

或者，当然，您可以让编译器为您完成工作:

trvDivisies.setOnEditCommit(p -> {

    // ...

});