Javafx Tableview MapValueFactory。如何编辑单元格并保存新值

Question

我用这个例子http://docs.oracle.com/javafx/2/ui_controls/table-view.htm其中tableview基于MapValueFactory。

现在我遇到了编辑后的值不保存的情况。我的行动：

按“回车”-

但当我在这个单元格中再次按“回车”时，会显示旧值而不是新值。

请帮助我了解编辑单元格后如何保存更改？

Example 12-12 Adding Map Data to the Table

import java.util.HashMap;
import java.util.Map;
import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.geometry.Insets;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.TableCell;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.MapValueFactory;
import javafx.scene.control.cell.TextFieldTableCell;
import javafx.scene.layout.VBox;
import javafx.scene.text.Font;
import javafx.stage.Stage;
import javafx.util.Callback;
import javafx.util.StringConverter;

public class TableViewSample extends Application {

    public static final String Column1MapKey = "A";
    public static final String Column2MapKey = "B";

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

    @Override
    public void start(Stage stage) {
        Scene scene = new Scene(new Group());
        stage.setTitle("Table View Sample");
        stage.setWidth(300);
        stage.setHeight(500);

        final Label label = new Label("Student IDs");
        label.setFont(new Font("Arial", 20));

        TableColumn<Map, String> firstDataColumn = new TableColumn<>("Class A");
        TableColumn<Map, String> secondDataColumn = new TableColumn<>("Class B");

        firstDataColumn.setCellValueFactory(new MapValueFactory(Column1MapKey));
        firstDataColumn.setMinWidth(130);
        secondDataColumn.setCellValueFactory(new MapValueFactory(Column2MapKey));
        secondDataColumn.setMinWidth(130);

        TableView table_view = new TableView<>(generateDataInMap());

        table_view.setEditable(true);
        table_view.getSelectionModel().setCellSelectionEnabled(true);
        table_view.getColumns().setAll(firstDataColumn, secondDataColumn);
        Callback<TableColumn<Map, String>, TableCell<Map, String>>
            cellFactoryForMap = new Callback<TableColumn<Map, String>,
                TableCell<Map, String>>() {
                    @Override
                    public TableCell call(TableColumn p) {
                        return new TextFieldTableCell(new StringConverter() {
                            @Override
                            public String toString(Object t) {
                                return t.toString();
                            }
                            @Override
                            public Object fromString(String string) {
                                return string;
                            }                                    
                        });
                    }
        };
        firstDataColumn.setCellFactory(cellFactoryForMap);
        secondDataColumn.setCellFactory(cellFactoryForMap);

        final VBox vbox = new VBox();

        vbox.setSpacing(5);
        vbox.setPadding(new Insets(10, 0, 0, 10));
        vbox.getChildren().addAll(label, table_view);

        ((Group) scene.getRoot()).getChildren().addAll(vbox);

        stage.setScene(scene);

        stage.show();
    }

    private ObservableList<Map> generateDataInMap() {
        int max = 10;
        ObservableList<Map> allData = FXCollections.observableArrayList();
        for (int i = 1; i < max; i++) {
            Map<String, String> dataRow = new HashMap<>();

            String value1 = "A" + i;
            String value2 = "B" + i;

            dataRow.put(Column1MapKey, value1);
            dataRow.put(Column2MapKey, value2);

            allData.add(dataRow);
        }
        return allData;
    }
}

Answer 1

您需要使用setOnEditCommit定义cellEditEvent：

    firstDataColumn.setOnEditCommit((CellEditEvent<Map<String, String>, String> t) -> {
        ((Map<String, String>) t.getTableView().getItems().get(t.getTablePosition().getRow())).put(Column1MapKey, t.getNewValue());
    });