Question

我正在尝试提交TableCell，但正在调用cancelEdit()。只有通过调用cell使tableView.edit()进入编辑状态，才会发生这种情况。

我通过以下方式致电editCommit()

private void handleKeyPressed(KeyEvent e) {
    if (e.getCode() == KeyCode.ENTER) {
        commitEdit(textField.getText());
    }
}

为什么按下回车键时会调用cancelEdit()？手动点击添加的空白行并按Enter键尝试提交单元格工作正常。

import java.util.function.Function;
import javafx.application.Application;
import javafx.beans.property.StringProperty;
import javafx.collections.FXCollections;
import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.VBox;
import javafx.scene.control.TableView;
import javafx.scene.control.Button;
import javafx.scene.control.ContentDisplay;
import javafx.scene.control.TableCell;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TextField;
import javafx.scene.input.KeyCode;
import javafx.scene.input.KeyEvent;
import javafx.beans.property.SimpleStringProperty;

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) {
        BorderPane root = new BorderPane();
        primaryStage.setScene(new Scene(root, 400, 400));
        primaryStage.show();
        root.setCenter(new TableExample());
    }

    public class TableExample extends VBox {
        public TableExample() {
            TableView<Building> tableView = new TableView<>();
            tableView.setEditable(true);

            //adds a new blank row to table;
            Button add = new Button("add");
            add.setOnAction(e -> {
                Building newBuilding = new Building();
                tableView.getItems().add(0, newBuilding);
                tableView.edit(0, tableView.getColumns().get(0));

                //I tried focusing and selecting the row
                //but does not help.
                tableView.getFocusModel().focus(0);
                tableView.getSelectionModel().select(0);

            });

            getChildren().addAll(add, tableView);

            Building building = new Building();
            building.setName("Building 100");

            Function<Building, StringProperty> property = Building::nameProperty;

            TableColumn<Building, String> column = new TableColumn<>("name");
            column.setEditable(true);
            column.setCellValueFactory(cellData -> property.apply(cellData.getValue()));
            column.setCellFactory(p -> new EditingStringCell<>());

            tableView.getColumns().add(column);
            tableView.setItems(FXCollections.observableArrayList(building));
        }
    }

    public class EditingStringCell<S, T> extends TableCell<Building, String> {
        private TextField textField;

        public EditingStringCell() {
            setEditable(true);
        }

        @Override
        protected void updateItem(String item, boolean empty) {
            super.updateItem(item, empty);
            setText(empty ? null : item);
        }

        @Override
        public void startEdit() {
            System.out.println("start edit");
            super.startEdit();
            buildControl(getItem());
            setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
        }

        private void buildControl(String item) {
            System.out.println("item: " + item);
            textField = new TextField();        
            textField.addEventHandler(KeyEvent.KEY_RELEASED, 
            this::handleKeyPressed);
            textField.setText(item == null ? "" : (item));
            setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
            setGraphic(textField);
        }

        //whenever pressing enter on a new "blank" row
        //cancelEdit() gets called. But if you try again 
        //it works.
        private void handleKeyPressed(KeyEvent e) {
            if (e.getCode() == KeyCode.ENTER) {
                commitEdit(textField.getText());
            }
        }

        @Override
        public void cancelEdit() {
            System.out.println("cancel edit");
            super.cancelEdit();
            setContentDisplay(ContentDisplay.TEXT_ONLY);
        }

        @Override
        public void commitEdit(String newValue) {
            System.out.println("commited: " + newValue);
            super.commitEdit(newValue);
            setContentDisplay(ContentDisplay.TEXT_ONLY);
        }
    }

    public class Building {
        private final StringProperty name = new SimpleStringProperty();
        public StringProperty nameProperty() {
            return name;
        }
        public String getName() {
            return name.get();
        }
        public void setName(String name) {
            this.name.set(name);
        }
    }
    public static void main(String[] args) {launch(args);}
}

Answer 1

基本上，TableView（以及其他虚拟化控件）在terminating an on-going edit时非常不正常：大多数情况下，当可用性需要提交时，它会取消编辑。

在您的示例中，有两个不同的（众所周知的）原因

修改项目列表时，在内部深处取消编辑，此处添加项目
编辑tableCell在检测到表格编辑位置发生变化时取消编辑

要查看，我在您的代码中添加了几个打印件：

演示问题1：

编辑第一项
点击添加按钮
预期：已保存已编辑的项目，新项目开始编辑
实际：未保存已编辑的项目，新项目开始编辑

打印出来：

start edit 0 on id: 2
before adding: TablePosition [ row: 0, column: ... ]
cancel edit 0 on id: 2
start edit 0 on id: 2
start edit 0 on id: 14   // <- some slightly weird cell re-use
cancel edit 12 on id: 2  // <- triggers a cancel on the old, functional interference unknown

演示问题2：

添加项目并编辑任何
点击编辑以开始编辑另一个
预期：首先编辑已保存，第二次编辑已开始
实际：首先编辑已取消，第二次编辑已开始

打印出来：

before starting edit on : 1
start edit 1 on id: 13
cancel edit 0 on id: 14

......不幸的是，没有太多（甚至没有）可以做的事情......

您的示例略有修改：

import java.util.function.Function;

import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.collections.FXCollections;
import javafx.event.ActionEvent;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
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.input.KeyCode;
import javafx.scene.input.KeyEvent;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

/**
 * https://stackoverflow.com/q/46396423/203657
 */
public class TableEditSO extends Application {

    @Override
    public void start(Stage primaryStage) {
        BorderPane root = new BorderPane();
        primaryStage.setScene(new Scene(root, 400, 400));
        primaryStage.show();
        //root.setCenter(new TableExample());
        root.setCenter(getContent());
    }

    private Parent getContent() {
        TableView<Building> tableView = new TableView<>();
        tableView.setEditable(true);

        //adds a new blank row to table;
        Button add = new Button("add");
        add.setOnAction(e -> {
            Building newBuilding = new Building();
            // modifications to the items will cancel an edit
            System.out.println("before adding: " + tableView.getEditingCell());
            tableView.getItems().add(0, newBuilding);
            tableView.edit(0, tableView.getColumns().get(0));

            //I tried focusing and selecting the row
            //but does not help.
            tableView.getFocusModel().focus(0);
            tableView.getSelectionModel().select(0);

        });

        Button edit = new Button("edit");
        edit.setOnAction(e -> {
            int size = tableView.getItems().size();
            if (size < 2) return;
            TablePosition pos = tableView.getEditingCell();
            int last = size - 1;
            if (pos != null) {
                int row = pos.getRow();
                if (row == last) {
                    //make certain we switch editing to another row
                    last--;
                }
            }
            System.out.println("before starting edit on : " + last);
            // starting edit on another item will cancel an edit
            tableView.edit(last, tableView.getColumns().get(0));
        });

        Building building = new Building();
        building.setName("Building 100");

        Function<Building, StringProperty> property = Building::nameProperty;

        TableColumn<Building, String> column = new TableColumn<>("name");
        column.setEditable(true);
        column.setCellValueFactory(cellData -> property.apply(cellData.getValue()));
        column.setCellFactory(p -> new EditingStringCell<>());

        tableView.getColumns().add(column);
        tableView.setItems(FXCollections.observableArrayList(building));

        VBox box = new VBox(10, add, edit, tableView);
        return box;
    }

    // don't extend without functional reason
    public class TableExample extends VBox {
        public TableExample() {
            TableView<Building> tableView = new TableView<>();
            tableView.setEditable(true);

            //adds a new blank row to table;
            Button add = new Button("add");
            add.setOnAction(e -> {
                Building newBuilding = new Building();
                System.out.println("before adding: " + tableView.getEditingCell());

                tableView.getItems().add(0, newBuilding);
                System.out.println("after adding: " + tableView.getEditingCell());
                tableView.edit(0, tableView.getColumns().get(0));
                System.out.println("after starting: " + tableView.getEditingCell());

                //I tried focusing and selecting the row
                //but does not help.
                tableView.getFocusModel().focus(0);
                tableView.getSelectionModel().select(0);

            });

            getChildren().addAll(add, tableView);

            Building building = new Building();
            building.setName("Building 100");

            Function<Building, StringProperty> property = Building::nameProperty;

            TableColumn<Building, String> column = new TableColumn<>("name");
            column.setEditable(true);
            column.setCellValueFactory(cellData -> property.apply(cellData.getValue()));
            column.setCellFactory(p -> new EditingStringCell<>());

            tableView.getColumns().add(column);
            tableView.setItems(FXCollections.observableArrayList(building));
        }
    }

    public static class EditingStringCell<S, T> extends TableCell<Building, String> {
        static int id ;
        private int myId;
        private TextField textField;

        public EditingStringCell() {
            // just to see re-use of cells
            myId = id++;
            setContentDisplay(ContentDisplay.TEXT_ONLY);
            // not needed, it's true by default
            // setEditable(true);
        }

        @Override
        protected void updateItem(String item, boolean empty) {
            super.updateItem(item, empty);
            setText(empty ? null : item);
        }

        @Override
        public void startEdit() {
            super.startEdit();
            if (isEditing()) {
                System.out.println("start edit " + getIndex() + " on id: " + myId);
                updateEditControl(getItem());

            }
        }

        private void updateEditControl(String item) {
            if (textField == null) {
                textField = new TextField();   
                // always use the highest abstract available
                // so use action instead of keyEvent
                textField.setOnAction(this::handleAction);
                //textField.addEventHandler(KeyEvent.KEY_PRESSED, 
                //        this::handleKeyPressed);
                setGraphic(textField);
            }
            textField.setText(item == null ? "" : (item));
            setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
        }

        private void handleAction(ActionEvent ae) {
            commitEdit(textField.getText());

        }

        //whenever pressing enter on a new "blank" row
        //cancelEdit() gets called. But if you try again 
        //it works.
        private void handleKeyPressed(KeyEvent e) {
            if (e.getCode() == KeyCode.ENTER) {
                commitEdit(textField.getText());
            }
        }

        @Override
        public void cancelEdit() {
            super.cancelEdit();
            System.out.println("cancel edit " + getIndex() + " on id: " + myId);
            setContentDisplay(ContentDisplay.TEXT_ONLY);
        }

        @Override
        public void commitEdit(String newValue) {
            super.commitEdit(newValue);
            System.out.println("commited: " + newValue + " index: " + getIndex() + " on id: " + myId);
            setContentDisplay(ContentDisplay.TEXT_ONLY);
        }
    }

    public class Building {
        private final StringProperty name = new SimpleStringProperty();
        public StringProperty nameProperty() {
            return name;
        }
        public String getName() {
            return name.get();
        }
        public void setName(String name) {
            this.name.set(name);
        }
    }
    public static void main(String[] args) {launch(args);}
}

Answer 2

代码中的问题是在buildControl（）方法中引起的，而不是每次触发新的编辑事件时使用您创建新文本的前一个TextField。您所要做的就是在EditingStringCell构造函数中移动TextField的初始化。

我测试了所有（我希望）的情况。在编辑时添加新行，在编辑时选择另一行，提交更改一切正常。这里差不多早上6点，所以我的想法不太清楚：P

尝试提交TableCell时正在调用cancelEdit（）

2 个答案: