JavaFX TableView 单元格设置值稍后答案

【问题标题】：JavaFX TableView cell set value laterJavaFX TableView 单元格设置值稍后
【发布时间】：2016-03-07 09:26:00
【问题描述】：

我有一个有 4 行的 TableView，每行都有一个自定义单元格。第一个只是一个图像，我想更新几次，一个字符串，一个带有自动换行的字符串和第二个图像作为按钮。

// image
tcUrlStatus.setCellValueFactory(new ColumnImageFactory());
tcUrlStatus.setCellFactory(new ColumnCallback());

// one line string
tcUrlName.setCellValueFactory(new ColumnNameFactory());
tcUrlName.setCellFactory(new ColumnCallback());

// two line string
tcUrlDate.setCellValueFactory(new ColumnDateFactory());
tcUrlDate.setCellFactory(new ColumnCallback());

// image as a button
tcDelete.setCellValueFactory(new ColumnDeleteFactory());
tcDelete.setCellFactory(new ColumnCallback());

这里是自定义单元格

class ColumnCallback implements Callback<TableColumn<Quartet<Boolean, String, String, String>, Object>, TableCell<Quartet<Boolean, String, String, String>, Object>>{
    @Override
    public TableCell<Quartet<Boolean, String, String, String>, Object> call(TableColumn<Quartet<Boolean, String, String, String>, Object> column) {
        return new ColumnCell();
    }
}

class ColumnImageFactory implements Callback<TableColumn.CellDataFeatures<Quartet<Object, String, String, String>, String>, ObservableValue<Object>> {
    @Override
    public ObservableValue<Object> call(TableColumn.CellDataFeatures<Quartet<Object, String, String, String>, String> data) {
        return new ReadOnlyObjectWrapper<>(data.getValue().getValue0());
    }
}

class ColumnNameFactory implements Callback<TableColumn.CellDataFeatures<Quartet<Boolean, String, String, String>, String>, ObservableValue<String>> {
    @Override
    public ObservableValue<String> call(TableColumn.CellDataFeatures<Quartet<Boolean, String, String, String>, String> data) {
        return new ReadOnlyObjectWrapper<>(data.getValue().getValue1());
    }
}

class ColumnDateFactory implements Callback<TableColumn.CellDataFeatures<Quartet<Boolean, String, String, String>, Object>, ObservableValue<Object>> {
    @Override
    public ObservableValue<Object> call(TableColumn.CellDataFeatures<Quartet<Boolean, String, String, String>, Object> data) {
        return new ReadOnlyObjectWrapper<>(data.getValue().getValue2());
    }
}

class ColumnDeleteFactory implements Callback<TableColumn.CellDataFeatures<Quartet<Boolean, String, String, String>, Object>, ObservableValue<Object>> {
    @Override
    public ObservableValue<Object> call(TableColumn.CellDataFeatures<Quartet<Boolean, String, String, String>, Object> data) {
        return new ReadOnlyObjectWrapper<>(data.getValue().getValue3());
    }
}

class ColumnCell extends TableCell<Quartet<Boolean, String, String, String>, Object> {
    @Override
    protected void updateItem(Object item, boolean empty) {
        super.updateItem(item, empty);

        if (item != null) {
            if (item instanceof Boolean) {
                setText(null);
                Image image;
                AnchorPane pane = new AnchorPane();

                if ((boolean) item) {
                    image = new Image(Main.class.getResourceAsStream("/hourglass.gif"));
                } else {
                    image = new Image(Main.class.getResourceAsStream("/clean.gif"));
                }

                ImageView imageView = new ImageView(image);
                imageView.setFitWidth(30);
                imageView.setY(5);
                imageView.setPreserveRatio(true);
                imageView.setSmooth(true);

                pane.getChildren().add(imageView);

                setGraphic(pane);
            }else {
                if (item instanceof String) {
                    if (item.equals("delete")) {
                        AnchorPane pane = new AnchorPane();

                        Image image = new Image(Main.class.getResourceAsStream("/cross.png"));

                        ImageView imageView = new ImageView(image);
                        imageView.setFitWidth(20);
                        imageView.setY(10);
                        imageView.setPreserveRatio(true);
                        imageView.setSmooth(true);
                        imageView.setCursor(Cursor.HAND);

                        pane.getChildren().add(imageView);

                        imageView.setOnMouseClicked((Event event) -> {
                            Quartet<Boolean, String, String, String> row = this.getTableView().getSelectionModel().getSelectedItem();

                            Controller.localJson.remove(row.getValue1());
                            this.getTableView().getItems().remove(row);
                        });

                        setGraphic(pane);
                    } else {
                        HBox pane = new HBox();
                        Label label = new Label();
                        label.setText((String) item);

                        label.setTextAlignment(TextAlignment.CENTER);

                        if (((String) item).length() < 20) {
                            label.setWrapText(true);
                            label.setAlignment(Pos.CENTER);
                        }

                        pane.setPrefHeight(40);
                        label.setPrefHeight(40);
                        pane.getChildren().add(label);

                        setGraphic(pane);
                    }

                    setText(null);
                }
            }
        } else {
            setText(null);
            setGraphic(null);
        }
    }
}

现在我想更改 tcUrlStatus 列/单元格的图像。我已经想出了如何获取行或它的值，但我不知道如何设置值或者更确切地说从 true 更改为 false 或从 false 更改为 true 以更新图像。

获取行和值：

private int getTableRowIndex(String url){ // url is the second column
    int counter = 0;
    for (Object row:tvUrls.getItems()){
        if ((((Quartet) row).getValue1() == url)){
            return counter;
        }
        counter ++;
    }

    return -1;
}

int rowIndex = getTableRowIndex(url);
Object item = tvUrls.getItems().get(rowIndex);

【问题讨论】：

标签： java javafx set tableview tablecell

【解决方案1】：

在 Quartet 类中使用 javafx 属性是最简单的方法，例如假设用于value0 bean 的类型是T：

// TODO: Is using a readonly property really needed here ???
//       if not, use SimpleObjectProperty instead
private final ReadOnlyObjectWrapper<T> value0 = new ReadOnlyObjectWrapper<>();

public T getValue0() {
     return value0.get();
}

// TODO: should the setter really be public ???
public void setValue0(T newValue) {
     value0.set(newValue);
}

public ReadOnlyObjectProperty<T> value0Property() {
    return value0.getReadOnlyProperty();
}

这允许您使用new PropertyValueFactory<>("value0") 而不是您的自定义单元格值工厂，更重要的是，这意味着TableView 组件将在Quartet 实例中收到更改通知。

这样你就可以简单地使用

quartetInstance.setValue0(newValue0);

并且单元格将得到更新。

在这种情况下，使用PropertyValueFactory 与使用以下cellValueFactory 具有相同的效果：

class ColumnImageFactory implements Callback<TableColumn.CellDataFeatures<Quartet<Object, String, String, String>, String>, ObservableValue<Object>> {
    @Override
    public ObservableValue<Object> call(TableColumn.CellDataFeatures<Quartet<Object, String, String, String>, String> data) {
        return data.getValue().value0Property();
    }
}

如果您无法将 javaFX 属性添加到 Quartet 类，您需要在更改后以其他方式更新 TableView。 TableView.refresh() 可以工作（前提是您使用 JavaFX 版本 >= 8u60）或编写 an adapter，以防您以其他方式在 Quartet 类中实现了观察者模式......

【讨论】：

我没有尝试，但我用另一种解决方案解决了“问题”。我使用了 SimpleObjectProperty。它比使用 Quartet 类更干净。我会马上发布它作为我的解决方案:)
@Mr.Tr33 是的，通常你有包含属性的项目，cellValueFactorys 返回这些属性之一，而不是创建一个新的；然后单元格将显示哪些属性，无论属性是否为只读。

【解决方案2】：

我通过从 Quartet 类转换为 SimpleObjectProperty 类解决了这个问题。

初始化：

tcUrlStatus.setCellValueFactory(new PropertyValueFactory<ColumnCellValue, Boolean>("status"));
tcUrlName.setCellValueFactory(new PropertyValueFactory<ColumnCellValue, String>("url"));
tcUrlDate.setCellValueFactory(new PropertyValueFactory<ColumnCellValue, String>("date"));
tcDelete.setCellValueFactory(new PropertyValueFactory<ColumnCellValue, Boolean>("delete"));

tcUrlStatus.setCellFactory(new ColumnStatusCell());
tcUrlName.setCellFactory(new ColumnStringCell(false));
tcUrlDate.setCellFactory(new ColumnStringCell(true));
tcDelete.setCellFactory(new ColumnDeleteCell());

添加行：

tvUrls.getItems().add(new ColumnCellValue(true, url, date));

更新单元格：

ColumnCellValue statusRow = (ColumnCellValue)
tvUrls.getItems().get(rowIndex);

列类：

public class ColumnCellValue{
    private final ObjectProperty status;
    private final ObjectProperty url;
    private final ObjectProperty date;
    private final ObjectProperty delete = new SimpleObjectProperty<Boolean>(true);

    ColumnCellValue(Boolean status, String url, String date) {
        this.status = new SimpleObjectProperty<Boolean>(status);
        this.url = new SimpleObjectProperty<String>(url);
        this.date = new SimpleObjectProperty<String>(date);
    }

    public Object getDate() {
        return date.get();
    }

    public ObjectProperty dateProperty() {
        return date;
    }

    public void setDate(Object date) {
        this.date.set(date);
    }

    public Object getDelete() {
        return delete.get();
    }

    public ObjectProperty deleteProperty() {
        return delete;
    }

    public void setDelete(Object delete) {
        this.delete.set(delete);
    }

    public Object getStatus() {
        return status.get();
    }

    public ObjectProperty statusProperty() {
        return status;
    }

    public void setStatus(Object status) {
        this.status.set(status);
    }

    public Object getUrl() {
        return url.get();
    }

    public ObjectProperty urlProperty() {
        return url;
    }

    public void setUrl(Object url) {
        this.url.set(url);
    }
}

class ColumnStatusCell implements Callback<TableColumn<Boolean, Boolean>,TableCell<Boolean, Boolean>>{
    @Override
    public TableCell<Boolean, Boolean> call(TableColumn<Boolean, Boolean> param) {
        AnchorPane pane = new AnchorPane();

        ImageView imageView = new ImageView();
        imageView.setFitWidth(30);
        imageView.setY(5);
        imageView.setPreserveRatio(true);
        imageView.setSmooth(true);

        TableCell<Boolean,Boolean> cell = new TableCell<Boolean,Boolean>(){
            public void updateItem(Boolean item, boolean empty) {
                if(item!=null){
                    Image image;

                    if (item) {
                        image = new Image(Main.class.getResourceAsStream("/hourglass.gif"));
                    } else {
                        image = new Image(Main.class.getResourceAsStream("/clean.gif"));
                    }

                    imageView.setImage(image);
                }
            }
        };

        pane.getChildren().add(imageView);
        cell.setGraphic(pane);

        return cell;
    }
}

class ColumnStringCell implements Callback<TableColumn<String, String>,TableCell<String, String>>{
    private boolean wrap = false;

    ColumnStringCell(boolean wrap){
        this.wrap = wrap;
    }

    @Override
    public TableCell<String, String> call(TableColumn<String, String> param) {
        TableCell<String,String> cell = new TableCell<String,String>(){
            public void updateItem(String item, boolean empty) {
                if(item!=null){
                    Label label = new Label();
                    label.setText(item);
                    label.setPrefHeight(40);
                    label.setTextAlignment(TextAlignment.CENTER);

                    label.setWrapText(wrap);

                    setGraphic(label);
                }
            }
        };

        return cell;
    }
}

class ColumnDeleteCell implements Callback<TableColumn<Boolean, Boolean>,TableCell<Boolean, Boolean>>{
    @Override
    public TableCell<Boolean, Boolean> call(TableColumn<Boolean, Boolean> param) {
        AnchorPane pane = new AnchorPane();

        ImageView imageView = new ImageView();
        imageView.setFitWidth(20);
        imageView.setY(10);
        imageView.setPreserveRatio(true);
        imageView.setSmooth(true);
        imageView.setCursor(Cursor.HAND);

        TableCell<Boolean,Boolean> cell = new TableCell<Boolean,Boolean>(){
            public void updateItem(Boolean item, boolean empty) {
                if (item != null) {
                    Image image = new Image(Main.class.getResourceAsStream("/cross.png"));
                    imageView.setImage(image);
                }
            }
        };

        imageView.setOnMouseClicked((Event event) -> {
            TableView table = (TableView) ((ImageView) event.getSource()).getParent().getParent().getParent().getParent().getParent().getParent().getParent();
            ColumnCellValue row = (ColumnCellValue) (table).getSelectionModel().getSelectedItem();

            Controller.localJson.remove(row.getUrl().toString());
            table.getItems().remove(row);

            table.refresh();
        });

        pane.getChildren().add(imageView);
        cell.setGraphic(pane);

        return cell;
    }
}

【讨论】：