获取 JavaFX 表中的复选框值

Get Checkbox value in a table in JavaFX

提问by Ravindu

I have a table and it has a column with checkboxes.

我有一张桌子，它有一列带有复选框。

On a button click I want to find out which checkboxes are checked and which are not. So far I managed to create checkboxes in a table. The code is as follows.

单击按钮时，我想找出哪些复选框已选中，哪些未选中。到目前为止，我设法在表格中创建了复选框。代码如下。

public class TTEs implements Initializable {

    @FXML
    private TableView<TestObject> tableReport;

    @FXML
    private TableColumn<TestObject, String> name;

    @FXML
    private TableColumn<TestObject, Boolean> checkbox;

    @FXML
    public void getValues() {        
        //the method will get what check boxes are checked (this part is the problem)
    }

    @Override
    public void initialize(URL arg0, ResourceBundle arg1) { 
        ObservableList<TestObject> data = FXCollections.observableArrayList();
        data.add(new TestObject("Test 1", true));
        data.add(new TestObject("Test 2", false));

        tableReport.setItems(data);

        name.setCellValueFactory(new PropertyValueFactory<TestObject, String>("name"));
        checkbox.setCellValueFactory(new PropertyValueFactory<TestObject, Boolean>("checked"));

        checkbox.setCellFactory(new Callback<TableColumn<TestObject, Boolean>,
            TableCell<TestObject, Boolean>>() {

            public TableCell<TestObject, Boolean> call(TableColumn<TestObject, Boolean> p) {
                return new CheckBoxTableCell<TestObject, Boolean>();
            }
        });
    }

    //CheckBoxTableCell for creating a CheckBox in a table cell
    public static class CheckBoxTableCell<S, T> extends TableCell<S, T> {
        private final CheckBox checkBox;
        private ObservableValue<T> ov;

        public CheckBoxTableCell() {
            this.checkBox = new CheckBox();
            this.checkBox.setAlignment(Pos.CENTER);

            setAlignment(Pos.CENTER);
            setGraphic(checkBox);
        } 

        @Override public void updateItem(T item, boolean empty) {
            super.updateItem(item, empty);
            if (empty) {
                setText(null);
                setGraphic(null);
            } else {
                setGraphic(checkBox);
                if (ov instanceof BooleanProperty) {
                    checkBox.selectedProperty().unbindBidirectional((BooleanProperty) ov);
                }
                ov = getTableColumn().getCellObservableValue(getIndex());
                if (ov instanceof BooleanProperty) {
                    checkBox.selectedProperty().bindBidirectional((BooleanProperty) ov);
                }
            }
        }
    }
}

When I debug, I find that:

当我调试时，我发现：

        ov = getTableColumn().getCellObservableValue(getIndex());
        if (ov instanceof BooleanProperty) {
            checkBox.selectedProperty().bindBidirectional((BooleanProperty) ov);
        }

In the above condition, it never goes inside the ifstatement, meaning that the ovis not an instance of BooleanProperty. But when I print the class of ov,

在上述条件下，它永远不会进入if语句内部，这意味着ov不是 的实例BooleanProperty。但是当我打印类时ov，

System.out.println(ov.getClass().getName());

it prints as

它打印为

javafx.beans.property.ReadOnlyObjectWrapper

ReadOnlyObjectWrapperis a subclass of BooleanProperty, so why is the instanceofcheck not working?

ReadOnlyObjectWrapper是 的子类BooleanProperty，那么为什么instanceof检查不起作用？

回答by Reegan Miranda

package checkboxtablecelltest;

import javafx.application.Application;
import javafx.beans.property.BooleanProperty;
import javafx.beans.property.SimpleBooleanProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.collections.FXCollections;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.SelectionMode;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.CheckBoxTableCell;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;

/**
 *
 * @author reegan
 */
public class CheckBoxTableCellTest extends Application {

    @Override   
    public void start(Stage primaryStage) {
        final TableView<Person> tableView = new TableView<Person>();
        tableView.getSelectionModel().setSelectionMode(SelectionMode.MULTIPLE);
        tableView.setItems(FXCollections.observableArrayList(
                new Person("Robert", "Plant"),
                new Person("Neil", "Young"),
                new Person("Willie", "Nelson"),
                new Person("Natalie", "Merchant")));
        tableView.getItems().get(3).setVegetarian(true);
        final TableColumn<Person, String> firstNameCol = new TableColumn<Person, String>("First Name");
        final TableColumn<Person, String> lastNameCol = new TableColumn<Person, String>("Last Name");
        final TableColumn<Person, Boolean> vegetarianCol = new TableColumn<Person, Boolean>("Vegetarian");
        tableView.getColumns().addAll(firstNameCol, lastNameCol, vegetarianCol);
        firstNameCol.setCellValueFactory(new PropertyValueFactory<Person, String>("firstName"));
        lastNameCol.setCellValueFactory(new PropertyValueFactory<Person, String>("lastName"));
        vegetarianCol.setCellValueFactory(new PropertyValueFactory<Person, Boolean>("vegetarian"));
        vegetarianCol.setCellFactory(CheckBoxTableCell.forTableColumn(vegetarianCol));
        vegetarianCol.setEditable(true);
        tableView.setEditable(true);

        final BorderPane root = new BorderPane();
        root.setCenter(tableView);

        final HBox controls = new HBox(5);
        final Button infoButton = new Button("Show details");
        infoButton.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent event) {
                for (Person p : tableView.getItems()) {
                    System.out.printf("%s %s (%svegetarian)%n", p.getFirstName(),
                            p.getLastName(), p.isVegetarian() ? "" : "not ");
                            System.out.println(tableView.getSelectionModel().getSelectedItems());

                }
                System.out.println();
            }
        });
        controls.getChildren().add(infoButton);
        root.setBottom(controls);

        Scene scene = new Scene(root, 300, 400);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

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

    public static class Person {

        private StringProperty firstName;
        private StringProperty lastName;
        private BooleanProperty vegetarian;

        public Person(String firstName, String lastName) {
            this.firstName = new SimpleStringProperty(firstName);
            this.lastName = new SimpleStringProperty(lastName);
            this.vegetarian = new SimpleBooleanProperty(false);
        }

        public String getFirstName() {
            return firstName.get();
        }

        public String getLastName() {
            return lastName.get();
        }

        public boolean isVegetarian() {
            return vegetarian.get();
        }

        public void setFirstName(String firstName) {
            this.firstName.set(firstName);
        }

        public void setLastName(String lastName) {
            this.lastName.set(lastName);
        }

        public void setVegetarian(boolean vegetarian) {
            this.vegetarian.set(vegetarian);
        }

        public StringProperty firstNameProperty() {
            return firstName;
        }

        public StringProperty lastNameProperty() {
            return lastName;
        }

        public BooleanProperty vegetarianProperty() {
            return vegetarian;
        }
    }
}

`

`

回答by OttPrime

Loop through the data model of your TableViewchecking the boolean value that is bound to each CheckBox.

循环TableView检查绑定到 each 的布尔值的数据模型CheckBox。

@FXML
public void getValues(){        
    ObservableList<TestObject> data = tableReport.getItems();

    for (TestObject item : data){
        //check the boolean value of each item to determine checkbox state
    }
}

回答by Jens-Peter Haack

The main problem with your approach is the CheckBoxTableCell usage: A Cell is a heavily reused 'rendering' machine. If you try to add a state, like the CheckBox variable, you are in trouble.

您的方法的主要问题是 CheckBoxTableCell 的使用：Cell 是重用的“渲染”机器。如果您尝试添加状态，例如 CheckBox 变量，则会遇到麻烦。

The most simple fix to your problem is to allocate the checkbox each time. The following code provides a working checkbox column:

解决问题的最简单方法是每次分配复选框。以下代码提供了一个有效的复选框列：

public static class Member {
    private StringProperty myName;
    private BooleanProperty myCheck;

    public Member(String name, boolean checked) {
        myName = new SimpleStringProperty(name);
        myCheck = new SimpleBooleanProperty(checked);
    }

    public StringProperty nameProperty() { return myName; }    
    public BooleanProperty checkProperty() { return myCheck; }
}

VBox testTable6(VBox box) { // check box bind to cell property
    ObservableList<Member> members = FXCollections.observableArrayList();

    members.add(new Member("peter", true));
    members.add(new Member("gernot", true));
    members.add(new Member("fritz", false));

    TableView<Member> table = new TableView<Member>();
    table.prefHeightProperty().bind(box.heightProperty());
    table.setItems(members);

    TableColumn<Member,String> c1 = new TableColumn<Member,String>("Name");
    c1.setCellValueFactory(new PropertyValueFactory<Member,String>("name"));
    table.getColumns().add(c1);

    TableColumn<Member,Boolean> c2 = new TableColumn<Member,Boolean>("Membercheck");
    c2.setCellValueFactory(new PropertyValueFactory<Member,Boolean>("check"));
    c2.setCellFactory(column -> new TableCell<Member, Boolean>(){
        public void updateItem(Boolean check, boolean empty) {
            super.updateItem(check, empty);
            if (check == null || empty) {
                setGraphic(null);
            } else {
                CheckBox box = new CheckBox();
                BooleanProperty checked = (BooleanProperty)column.getCellObservableValue(getIndex());
                box.setSelected(checked.get());
                box.selectedProperty().bindBidirectional(checked);
                setGraphic(box);
            }
        }
    }
            );
    table.getColumns().add(c2);

    box.getChildren().addAll(table);
    return box;
}

As the bidirectional property binding is a weak binding, carbage collection will work properly even if you are unable to unbind explicitely.

由于双向属性绑定是弱绑定，即使您无法明确解除绑定，carbage 收集也能正常工作。

The unchecked cast to BooleanProperty is not a good style anyhow here, sorry. Consider to access the whole object using:

无论如何，对 BooleanProperty 的未经检查的强制转换在这里不是一个好的风格，抱歉。考虑使用以下方法访问整个对象：

...
Member member = table.getItems().get(getIndex());
box.setSelected(member.checkProperty().get());
box.selectedProperty().bindBidirectional(member.checkProperty());
....

by the way: the birdeirectional binding will NOT set the selected property in that moment, only if it is changed afterward! so the explicit assignment:

顺便说一句：birdeirectional 绑定不会在那一刻设置 selected 属性，只有在之后更改它！所以显式赋值：

box.setSelected(member.checkProperty().get());

is mandatory here.

这里是强制性的。

回答by gotozero

Tested on Java 8.
Only 4 simple things.

在 Java 8 上测试。
只有 4 件简单的事情。

1) Make CheckBoxCellFactory class. Put somewhere in your project.

1) 创建 CheckBoxCellFactory 类。放在你的项目中的某个地方。

public class CheckBoxCellFactory implements Callback {
    @Override
    public TableCell call(Object param) {
        CheckBoxTableCell<Person,Boolean> checkBoxCell = new CheckBoxTableCell();
        return checkBoxCell;
    }
}

2) Your model class. Person for example.

2）你的模型类。以人为例。

public static class Person {
   private SimpleBooleanProperty checked = new SimpleBooleanProperty(false);
   // other columns here

    public SimpleBooleanProperty checkedProperty() {
        return this.checked;
    }

    public java.lang.Boolean getChecked() {
        return this.checkedProperty().get();
    }

    public void setChecked(final java.lang.Boolean checked) {
        this.checkedProperty().set(checked);
    }

    // getter/setter for other columns

}

3) Made modifications in your fxml file. The section of your TableView -> TableColumn gonna look like this:

3) 在您的 fxml 文件中进行了修改。您的 TableView -> TableColumn 的部分将如下所示：

<TableColumn fx:id="checkBoxTableColumn" maxWidth="34.0" minWidth="26.0" prefWidth="34.0" resizable="false" sortable="false">   
<cellValueFactory><PropertyValueFactory property="checked" /></cellValueFactory>
<cellFactory><partarch.fx.CheckBoxCellFactory /></cellFactory>
</TableColumn>

4) If you want to make your checkbox being editable

4) 如果你想让你的复选框可编辑

• 4.1 Open fxml in the Scene Builder.
• 4.2 Select checkBox column and then check "Editable" property in the Properties pane.
• 4.3 Select TableView containing your checkbox and do the same(check "Editable" property in the Properties pane).

• 4.1 在场景生成器中打开 fxml。
• 4.2 选择复选框列，然后在属性窗格中选中“可编辑”属性。
• 4.3 选择包含您的复选框的 TableView 并执行相同的操作（选中“属性”窗格中的“可编辑”属性）。

Implementation in binaries on SFand source on GitHub

在SF上的二进制文件和GitHub 上的源代码中实现

回答by user1210708

A little off topic - but in Kotlin you can do this:

有点离题 - 但在 Kotlin 中你可以这样做：

    isPvtColumn.cellFactory = Callback { CheckBoxTableCell<KeyWithProperties, Boolean>() }

    isPvtColumn.cellValueFactory = Callback {
        a -> a.value.private
    }

This is all there is to it

这就是它的全部

回答by Antonio Gabriel Andrade

In the initialize method, switch your custom factory for the one provided by JavaFX:

在 initialize 方法中，将自定义工厂切换为 JavaFX 提供的工厂：

@Override
public void initialize(URL arg0, ResourceBundle arg1) {

     ObservableList<TestObject> data = FXCollections.observableArrayList();
     data.add(new TestObject("Test 1", true));
     data.add(new TestObject("Test 2", false));

     tableReport.setItems(data);

     name.setCellValueFactory(new PropertyValueFactory<TestObject, String>("name"));
     checkbox.setCellValueFactory(new PropertyValueFactory<TestObject, Boolean>("checked"));

     checkbox.setCellFactory(
         CheckBoxTableCell.forTableColumn(checkbox)
     );

}

Now your data is binded to the column and you can iterate over the items and check for the "checked" field:

现在您的数据已绑定到该列，您可以遍历项目并检查“已检查”字段：

@FXML
public void getValues(){        
    ObservableList<TestObject> data = tableReport.getItems();

    for (TestObject item : data){
        //check the boolean value of each item to determine checkbox state
    }
}