单击单元格进行编辑时，JavaFX 8 TreeView 显示不正确的字符串

Question

我正在使用来自 Oracle 的以下代码：

import java.util.Arrays;
import java.util.List;
import javafx.application.Application;
import javafx.event.Event;
import javafx.event.EventHandler;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.scene.control.TreeCell;
import javafx.scene.control.TreeItem;
import javafx.scene.control.TreeView;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.input.KeyCode;
import javafx.scene.input.KeyEvent;
import javafx.scene.paint.Color;
import javafx.stage.Stage;
import javafx.util.Callback;

import javafx.beans.property.SimpleStringProperty;
import javafx.scene.control.ContextMenu;
import javafx.scene.control.MenuItem;
import javafx.scene.layout.VBox;

public class TreeViewSample extends Application {

List<Employee> employees = Arrays.<Employee>asList(
        new Employee("Ethan Williams", "Sales Department"),
        new Employee("Emma Jones", "Sales Department"),
        new Employee("Michael Brown", "Sales Department"),
        new Employee("Anna Black", "Sales Department"),
        new Employee("Rodger York", "Sales Department"),
        new Employee("Susan Collins", "Sales Department"),
        new Employee("Mike Graham", "IT Support"),
        new Employee("Judy Mayer", "IT Support"),
        new Employee("Gregory Smith", "IT Support"),
        new Employee("Jacob Smith", "Accounts Department"),
        new Employee("Isabella Johnson", "Accounts Department"));
TreeItem<String> rootNode = 
    new TreeItem<String>("MyCompany Human Resources");

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

@Override
public void start(Stage stage) {
    rootNode.setExpanded(true);
    for (Employee employee : employees) {
        TreeItem<String> empLeaf = new TreeItem<String>(employee.getName());
        boolean found = false;
        for (TreeItem<String> depNode : rootNode.getChildren()) {
            if (depNode.getValue().contentEquals(employee.getDepartment())){
                depNode.getChildren().add(empLeaf);
                found = true;
                break;
            }
        }
        if (!found) {
            TreeItem depNode = new TreeItem(employee.getDepartment());
            rootNode.getChildren().add(depNode);
            depNode.getChildren().add(empLeaf);
        }
    }

    stage.setTitle("Tree View Sample");
    VBox box = new VBox();
    final Scene scene = new Scene(box, 400, 300);
    scene.setFill(Color.LIGHTGRAY);

    TreeView<String> treeView = new TreeView<String>(rootNode);
    treeView.setEditable(true);
    treeView.setCellFactory(new Callback<TreeView<String>,TreeCell<String>>(){
        @Override
        public TreeCell<String> call(TreeView<String> p) {
            return new TextFieldTreeCellImpl();
        }
    });

    box.getChildren().add(treeView);
    stage.setScene(scene);
    stage.show();
}

private final class TextFieldTreeCellImpl extends TreeCell<String> {

    private TextField textField;
    private ContextMenu addMenu = new ContextMenu();

    public TextFieldTreeCellImpl() {
        MenuItem addMenuItem = new MenuItem("Add Employee");
        addMenu.getItems().add(addMenuItem);
        addMenuItem.setOnAction(new EventHandler() {
            public void handle(Event t) {
                TreeItem newEmployee = 
                    new TreeItem<String>("New Employee");
                        getTreeItem().getChildren().add(newEmployee);
            }
        });
    }

    @Override
    public void startEdit() {
        super.startEdit();

        if (textField == null) {
            createTextField();
        }
        setText(null);
        setGraphic(textField);
        textField.selectAll();
    }

    @Override
    public void cancelEdit() {
        super.cancelEdit();

        setText((String) getItem());
        setGraphic(getTreeItem().getGraphic());
    }

    @Override
    public void updateItem(String item, boolean empty) {
        super.updateItem(item, empty);

        if (empty) {
            setText(null);
            setGraphic(null);
        } else {
            if (isEditing()) {
                if (textField != null) {
                    textField.setText(getString());
                }
                setText(null);
                setGraphic(textField);
            } else {
                setText(getString());
                setGraphic(getTreeItem().getGraphic());
                if (
                    !getTreeItem().isLeaf()&&getTreeItem().getParent()!= null
                ){
                    setContextMenu(addMenu);
                }
            }
        }
    }

    private void createTextField() {
        textField = new TextField(getString());
        textField.setOnKeyReleased(new EventHandler<KeyEvent>() {

            @Override
            public void handle(KeyEvent t) {
                if (t.getCode() == KeyCode.ENTER) {
                    commitEdit(textField.getText());
                } else if (t.getCode() == KeyCode.ESCAPE) {
                    cancelEdit();
                }
            }
        });  

    }

    private String getString() {
        return getItem() == null ? "" : getItem().toString();
    }
}

public static class Employee {

    private final SimpleStringProperty name;
    private final SimpleStringProperty department;

    private Employee(String name, String department) {
        this.name = new SimpleStringProperty(name);
        this.department = new SimpleStringProperty(department);
    }

    public String getName() {
        return name.get();
    }

    public void setName(String fName) {
        name.set(fName);
    }

    public String getDepartment() {
        return department.get();
    }

    public void setDepartment(String fName) {
        department.set(fName);
    }
}
}

此代码生成一个带有非常基本的可编辑 TreeView 的 GUI。但是，当单击填充树的单元格时，最终，用于编辑的文本字段将开始显示不正确的信息（树中包含的信息，但未由正在编辑的单元格表示的信息）。我不明白为什么会这样，而且我在 Google 或 Whosebug 的其他地方也没有发现任何关于这种情况的参考资料。如果有人能帮助我理解为什么会这样，我会很高兴。

谢谢！

Answer 1

我检查了你的申请，只发现了一件奇怪的事情。当您创建一次编辑文本字段时，未保存的信息稍后将在该文本字段中可见。

此修改将解决它：

@ Override
public void cancelEdit() {
    super.cancelEdit();

    this.setText(this.getItem());
    this.textField.setText(this.getItem());
    this.setGraphic(this.getTreeItem().getGraphic());
}

单击单元格进行编辑时，JavaFX 8 TreeView 显示不正确的字符串

JavaFX 8 TreeView displays incorrect String when cell is clicked to edit

java

javafx

treeview

textfield

treecell