TableVew - 抛出 KeyEvent 时编辑单元格

Question

我在 TableView 上有一个监听键盘事件的事件监听器。

 // Add event listener to table
 table.setOnKeyTyped(event -> {
        TablePosition<SimpleStringProperty, String> focusedCell = table.getFocusModel().getFocusedCell();
        if (focusedCell != null)
        {
            table.getItems().get(focusedCell.getRow()).set(event.getCharacter());
            table.edit(focusedCell.getRow(), focusedCell.getTableColumn());
        }
    });

当用户单击输入或将焦点更改到另一个单元格时，我无法使用新数据更新单元格。当您单击输入或更改焦点时，单元格变为空。我不确定为什么。如何保存数据并使用新数据更新单元格。

// Here is the full code.
import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.scene.control.ContentDisplay;
import javafx.scene.control.TableCell;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TablePosition;
import javafx.scene.control.TableView;
import javafx.scene.control.TextField;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;

public class TableViewEdit extends Application
{

@Override
public void start(Stage primaryStage)
{
    TableView<SimpleStringProperty> table = new TableView<SimpleStringProperty>();
    table.getSelectionModel().setCellSelectionEnabled(true);
    table.setEditable(true);

    table.getColumns().add(this.createColumn());

    ObservableList<SimpleStringProperty> rowData = FXCollections.observableArrayList();
    //table.getItems().addAll(rowData);
    for (int j = 0; j < 10; j++)
    {
        rowData.add(new SimpleStringProperty(String.format("Cell [%d", j)));
    }

    table.setItems(rowData);

    table.setOnKeyTyped(event -> {
        TablePosition<SimpleStringProperty, String> focusedCell = table.getFocusModel().getFocusedCell();
        if (focusedCell != null)
        {
            table.getItems().get(focusedCell.getRow()).set(event.getCharacter());
            table.edit(focusedCell.getRow(), focusedCell.getTableColumn());
        }
    });

    Scene scene = new Scene(new BorderPane(table), 880, 600);
    primaryStage.setScene(scene);
    primaryStage.show();
}

private TableColumn<SimpleStringProperty, String> createColumn()
{
    TableColumn<SimpleStringProperty, String> col = new TableColumn<>("Column ");
    col.setCellValueFactory(cellData -> cellData.getValue());
    col.setCellFactory(column -> new EditCell());
    return col;
}

private static class EditCell extends TableCell<SimpleStringProperty, String>
{

    private final TextField textField = new TextField();

    EditCell()
    {
        this.textProperty().bind(this.itemProperty());
        this.setGraphic(this.textField);
        this.setContentDisplay(ContentDisplay.TEXT_ONLY);

        this.textField.setOnAction(evt -> this.commitEdit(this.textField.getText()));
        this.textField.focusedProperty().addListener((obs, wasFocused, isNowFocused) -> {
            if (!isNowFocused)
            {
                this.commitEdit(this.textField.getText());
            }
        });
    }

    @Override
    public void startEdit()
    {
        super.startEdit();
        this.textField.setText(this.getItem());
        this.setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
        this.textField.requestFocus();
    }

    @Override
    public void cancelEdit()
    {
        super.cancelEdit();
        this.setContentDisplay(ContentDisplay.TEXT_ONLY);
    }

    @Override
    public void commitEdit(String text)
    {
        super.commitEdit(text);
        this.setContentDisplay(ContentDisplay.TEXT_ONLY);
    }

}

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

Answer 1

这些真的很棘手；我认为任何 "behavior-related"（即对用户输入作出反应的标准控件）都很难更改，并且在 JavaFX 中通常得不到很好的支持。希望这是 API 将得到改进的领域...

似乎有几个不同的问题。我认为 Enter 键发生的事情是，虽然这会在文本字段上生成一个 ActionEvent，提交编辑等，但 keyTyped 事件仍然传播回 table, 使其重新进入编辑模式。解决此问题的方法似乎是在 table 上使用 keyPressed 处理程序（尽管老实说，这感觉不太稳健）。

代码依赖 table 列上的默认 onEditCommit 处理程序来实际更改属性值。 onEditCommit 处理程序由默认的 table 单元格的 commitEdit 方法调用。在失去焦点时调用 commitEdit(...) 的问题是默认的 commitEdit 方法首先检查单元格是否处于编辑状态，如果不是，则不执行任何操作。似乎当单元格失去焦点时，它会在调用 focusProperty 侦听器之前退出编辑状态，因此永远不会调用 onEditCommit 处理程序。（顺便说一句，这也会阻止示例 13-11 "Alternative solution of cell editing"（原文如此）在 JDK 8 u25（当前版本）中正常工作。）

对于第二个问题，我能看到的唯一修复方法是直接从 commitEdit(...) 方法更新属性。这要求单元格具有对属性的引用，这打破了单元格和单元格值之间的良好分离。

我使用通常的 Person 示例重写了示例，并合并了这两个修复程序。这个例子工作得很好，尽管正如我所说的，有些部分感觉它们不是很健壮：

import java.util.function.Function;

import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.scene.Scene;
import javafx.scene.control.ContentDisplay;
import javafx.scene.control.TableCell;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TablePosition;
import javafx.scene.control.TableView;
import javafx.scene.control.TextField;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;


public class TableViewEditOnType extends Application {


    @Override
    public void start(Stage primaryStage) {

        TableView<Person> table = new TableView<>();

        table.getSelectionModel().setCellSelectionEnabled(true);
        table.setEditable(true);

        table.getColumns().add(createColumn("First Name", Person::firstNameProperty));
        table.getColumns().add(createColumn("Last Name", Person::lastNameProperty));
        table.getColumns().add(createColumn("Email", Person::emailProperty));

        table.getItems().addAll(
                new Person("Jacob", "Smith", "jacob.smith@example.com"),
                new Person("Isabella", "Johnson", "isabella.johnson@example.com"),
                new Person("Ethan", "Williams", "ethan.williams@example.com"),
                new Person("Emma", "Jones", "emma.jones@example.com"),
                new Person("Michael", "Brown", "michael.brown@example.com")
        );

        table.setOnKeyPressed(event -> {
            TablePosition<Person, ?> pos = table.getFocusModel().getFocusedCell() ;
            if (pos != null) {
                table.edit(pos.getRow(), pos.getTableColumn());
            }
        });

        Scene scene = new Scene(new BorderPane(table), 880, 600);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    private TableColumn<Person, String> createColumn(String title, Function<Person, StringProperty> property) {
        TableColumn<Person, String> col = new TableColumn<>(title);
        col.setCellValueFactory(cellData -> property.apply(cellData.getValue()));

        col.setCellFactory(column -> new EditCell(property));

        return col ;
    }

    private static class EditCell extends TableCell<Person, String> {

        private final TextField textField = new TextField();

        private final Function<Person, StringProperty> property ;

        EditCell(Function<Person, StringProperty> property) {
            this.property = property ;

            textProperty().bind(itemProperty());
            setGraphic(textField);
            setContentDisplay(ContentDisplay.TEXT_ONLY);

            textField.setOnAction(evt -> {
                commitEdit(textField.getText());
            });
            textField.focusedProperty().addListener((obs, wasFocused, isNowFocused) -> {
                if (! isNowFocused) {
                    commitEdit(textField.getText());
                }
            });
        }

        @Override
        public void startEdit() {
            super.startEdit();
            textField.setText(getItem());
            setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
            textField.requestFocus();          
        }

        @Override
        public void cancelEdit() {
            super.cancelEdit();
            setContentDisplay(ContentDisplay.TEXT_ONLY);
        }

        @Override
        public void commitEdit(String text) {
            super.commitEdit(text);
            Person person = getTableView().getItems().get(getIndex()) ;
            StringProperty cellProperty = property.apply(person);
            cellProperty.set(text);
            setContentDisplay(ContentDisplay.TEXT_ONLY);
        }

    }

    public static class Person {
        private final StringProperty firstName = new SimpleStringProperty();
        private final StringProperty lastName = new SimpleStringProperty();
        private final StringProperty email = new SimpleStringProperty();

        public Person(String firstName, String lastName, String email) {
            setFirstName(firstName);
            setLastName(lastName);
            setEmail(email);
        }

        public final StringProperty firstNameProperty() {
            return this.firstName;
        }

        public final java.lang.String getFirstName() {
            return this.firstNameProperty().get();
        }

        public final void setFirstName(final java.lang.String firstName) {
            this.firstNameProperty().set(firstName);
        }

        public final StringProperty lastNameProperty() {
            return this.lastName;
        }

        public final java.lang.String getLastName() {
            return this.lastNameProperty().get();
        }

        public final void setLastName(final java.lang.String lastName) {
            this.lastNameProperty().set(lastName);
        }

        public final StringProperty emailProperty() {
            return this.email;
        }

        public final java.lang.String getEmail() {
            return this.emailProperty().get();
        }

        public final void setEmail(final java.lang.String email) {
            this.emailProperty().set(email);
        }


    }

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

TableVew - 抛出 KeyEvent 时编辑单元格

TableVew - Edit cell when KeyEvent is thrown

java

javafx

focus

tableview