在一列中添加两个按钮，并获得单击行值javafx

Question

我正在尝试在javafx的表格视图中实现一列中的两个按钮。我能够在一列中实现一个按钮，但无法在一列中添加两个按钮。我从这个链接中得到了一些想法

如何在JavaFX表视图中添加按钮

在TableView（JAVAFX）中的单元格中添加按钮

如何在TableView JavaFX的表列中添加两个按钮

我在上面的链接中使用了这个想法。然而，代码对我不起作用。

    TableColumn<Student, String> firstCol = new TableColumn<Student, String>("ID");
    TableColumn<Student, String> secondCol = new TableColumn<Student, String>("Name");
    TableColumn<Student, String> thirdCol = new TableColumn<Student, String>("Quiz Mark");
    TableColumn<Student, String> forthCol = new TableColumn<Student, String>("A1");
    TableColumn<Student, String> fifthCol = new TableColumn<Student, String>("A2");
    TableColumn<Student, String> sixthCol = new TableColumn<Student, String>("A3");
    TableColumn<Student, String> sevenCol = new TableColumn<Student, String>("Exam");
    TableColumn<Student, String> eightCol = new TableColumn<Student, String>("Result");
    TableColumn<Student, String> nineCol = new TableColumn<Student, String>("Grade");
    TableColumn<Student, Student> tenthCol = new TableColumn<Student, Student>("Action");   


firstCol.setCellValueFactory(new PropertyValueFactory<>("Id"));
    secondCol.setCellValueFactory(new PropertyValueFactory<>("Name"));
    thirdCol.setCellValueFactory(new PropertyValueFactory<>("QuizMark"));
    forthCol.setCellValueFactory(new PropertyValueFactory<>("Assingment1Mark"));
    fifthCol.setCellValueFactory(new PropertyValueFactory<>("Assingment2Mark"));
    sixthCol.setCellValueFactory(new PropertyValueFactory<>("Assingment3Mark"));
    sevenCol.setCellValueFactory(new PropertyValueFactory<>("ExamMark"));
    eightCol.setCellValueFactory(new PropertyValueFactory<>("Result"));
    nineCol.setCellValueFactory(new PropertyValueFactory<>("Grade"));
    tenthCol.setCellFactory(param -> new TableCell<Student, Student>() {
        private final Button editButton = new Button("edit");
        private final Button deleteButton = new Button("delete");
        HBox pane = new HBox(deleteButton, editButton);

        @Override
        protected void updateItem(Student patient, boolean empty) {
            super.updateItem(patient, empty);

            if (patient == null) {
                setGraphic(null);
                return;
            }

            deleteButton.setOnAction(event -> {
                Student getPatient = getTableView().getItems().get(getIndex());
                System.out.println(getPatient.getId() + "   " + getPatient.getName());
            });

            editButton.setOnAction(event -> {
                Student getPatient = getTableView().getItems().get(getIndex());
            });
            pane.getChildren().addAll(deleteButton,editButton);
            setGraphic(pane);
        }
    });

在中，不会显示“操作”列按钮。我哪里做错了。请任何人告诉我。

Answer 1

缺少cellValueFactory第十列中的单元格项总是null。使用updateItem方法的第二个参数来确定行是否为空。

为了说明这一点，我将列的类型更改为TableColumn

此外，每次更改项目时再次添加HBox的子级是不必要的，因为更新onAction处理程序也是不必要的，因为getIndex（）是在单击Button时评估的。

您可以将代码更改为：

TableColumn<Student, Void> tenthCol = new TableColumn<>("Action");

...

tenthCol.setCellFactory(param -> new TableCell<Student, Void>() {
    private final Button editButton = new Button("edit");
    private final Button deleteButton = new Button("delete");
    private final HBox pane = new HBox(deleteButton, editButton);

    {
        deleteButton.setOnAction(event -> {
            Student getPatient = getTableView().getItems().get(getIndex());
            System.out.println(getPatient.getId() + "   " + getPatient.getName());
        });

        editButton.setOnAction(event -> {
            Student getPatient = getTableView().getItems().get(getIndex());
        });
    }

    @Override
    protected void updateItem(Void item, boolean empty) {
        super.updateItem(item, empty);

        setGraphic(empty ? null : pane);
    }
});