Question

我读过这篇文章： http://code.makery.ch/blog/javafx-8-tableview-sorting-filtering/ 但是我对包含Long值而不是String的列有问题。



@FXML
private TableView<Person> personTable;
@FXML
private TableColumn<Person, String> firstNameColumn;
@FXML
private TableColumn<Person, Long> lastNameColumn;

@FXML
private void initialize() {
    // 0. Initialize the columns.
    firstNameColumn.setCellValueFactory((TableColumn.CellDataFeatures<Person, String> cellData) -> {
        return cellData.getValue().firstNameProperty();
    });

    firstNameColumn.setCellValueFactory(new Callback<TableColumn.CellDataFeatures<Person, String>,
            ObservableValue<String>>() {
        @Override
        public ObservableValue<String> call(TableColumn.CellDataFeatures<Person, String> param) {
            return new SimpleStringProperty("str"); // HERE IS OK
        }
    });

lastNameColumn.setCellValueFactory(new Callback<TableColumn.CellDataFeatures<Person, Long>, ObservableValue<Long>>() {
    @Override
    public ObservableValue<Long> call(TableColumn.CellDataFeatures<Person, Long> param) {
        return new SimpleLongProperty(14L); // HERE IS WRONG 
        // Incompatible types.
        // Required: ObservableValue<java.lang.Long>
        // Found: SimpleLongProperty
    }
});

@FXML private TableView<Person> personTable; @FXML private TableColumn<Person, String> firstNameColumn; @FXML private TableColumn<Person, Long> lastNameColumn; @FXML private void initialize() { // 0. Initialize the columns. firstNameColumn.setCellValueFactory((TableColumn.CellDataFeatures<Person, String> cellData) -> { return cellData.getValue().firstNameProperty(); }); firstNameColumn.setCellValueFactory(new Callback<TableColumn.CellDataFeatures<Person, String>, ObservableValue<String>>() { @Override public ObservableValue<String> call(TableColumn.CellDataFeatures<Person, String> param) { return new SimpleStringProperty("str"); // HERE IS OK } }); lastNameColumn.setCellValueFactory(new Callback<TableColumn.CellDataFeatures<Person, Long>, ObservableValue<Long>>() { @Override public ObservableValue<Long> call(TableColumn.CellDataFeatures<Person, Long> param) { return new SimpleLongProperty(14L); // HERE IS WRONG // Incompatible types. // Required: ObservableValue<java.lang.Long> // Found: SimpleLongProperty } });

我在代码中写入错误。

任何人都知道，我做错了什么？

感谢。

Answer 1

有些违反直觉，LongProperty实施ObservableValue<Number>，而不是ObservableValue<Long>。如果适合您的要求，最简单的解决方法是让您的TableColumn类型Number：

@FXML
private TableColumn<Person, Number> lastNameColumn;

lastNameColumn.setCellValueFactory(new Callback<TableColumn.CellDataFeatures<Person, Number>, ObservableValue<Number>>() {
    @Override
    public ObservableValue<Number> call(TableColumn.CellDataFeatures<Person, Number> param) {
        return new SimpleLongProperty(14L); 

    }
});

如果您确实需要列类型为Long，则需要执行

lastNameColumn.setCellValueFactory(new Callback<TableColumn.CellDataFeatures<Person, Long>, ObservableValue<Long>>() {
    @Override
    public ObservableValue<Long> call(TableColumn.CellDataFeatures<Person, Long> param) {
        return new SimpleObjectProperty<Long>(14L); 

    }
});

JavaFX 8 TableView过滤

1 个答案: