java - 如何将按钮添加到一列 TableView 中的单行？

Question

我有一个只有一个列的 TableView，我想在该 TableView/Column 的最后一行有一个按钮。在选择一行之前，按钮应该被禁用，然后它应该被启用。我对此进行了大量搜索，但我发现的所有内容似乎都在向多列表中的每一行添加一个按钮。有没有快速的方法来做到这一点？

以下是一些示例图片:

TableButtonView.fxml:

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.ButtonBar?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.control.TableColumn?>
<?import javafx.scene.control.TableView?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.layout.VBox?>
<?import javafx.scene.text.Font?>

<AnchorPane maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" prefHeight="406.0" prefWidth="200.0" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="tablebutton.TableButtonController">
   <children>
      <VBox layoutX="60.0" layoutY="22.0" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" prefHeight="200.0" prefWidth="100.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
         <children>
            <Label alignment="CENTER" maxWidth="1.7976931348623157E308" prefHeight="51.0" prefWidth="200.0" text="Agency Customization">
               <font>
                  <Font name="System Bold" size="13.0" />
               </font>
            </Label>
            <HBox maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" prefHeight="40.0">
               <children>
                  <Label alignment="CENTER_RIGHT" maxHeight="1.7976931348623157E308" prefHeight="30.0" prefWidth="70.0" text="Agency:  " />
                  <TextField fx:id="agencyTextField" maxHeight="1.7976931348623157E308" prefHeight="30.0" prefWidth="45.0" />
                  <Button fx:id="addButton" maxHeight="1.7976931348623157E308" onAction="#onAdd" prefHeight="30.0" prefWidth="67.0" text="_Add">
                     <HBox.margin>
                        <Insets left="10.0" />
                     </HBox.margin>
                  </Button>
               </children>
               <padding>
                  <Insets bottom="10.0" />
               </padding>
            </HBox>
            <TableView fx:id="agencyTableView" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" prefHeight="276.0">
               <columns>
                  <TableColumn fx:id="agencyColumn" prefWidth="188.0" text="Agency" />
               </columns>
               <VBox.margin>
                  <Insets left="5.0" right="5.0" />
               </VBox.margin>
            </TableView>
            <ButtonBar maxWidth="1.7976931348623157E308">
               <buttons>
                  <Button fx:id="okAgencyButton" mnemonicParsing="false" onAction="#onOK" text="OK" />
                  <Button fx:id="cancelAgencyButton" mnemonicParsing="false" onAction="#onCancel" text="Cancel" />
               </buttons>
               <padding>
                  <Insets bottom="5.0" right="20.0" top="5.0" />
               </padding>
            </ButtonBar>
         </children>
      </VBox>
   </children>
</AnchorPane>

TableButtonController.java:

package tablebutton;

import java.net.URL;
import java.util.ResourceBundle;
import javafx.beans.property.ReadOnlyStringWrapper;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Button;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.TextField;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

public class TableButtonController implements Initializable {

    private WebView helpWebView;
    @FXML
    private TextField agencyTextField;
    @FXML
    private Button addButton;
    @FXML
    private TableView<String> agencyTableView;
    @FXML
    private TableColumn<String, String> agencyColumn;
    @FXML
    private Button okAgencyButton;
    @FXML
    private Button cancelAgencyButton;

    @Override
    public void initialize(URL url, ResourceBundle rb) {
        agencyColumn.setCellValueFactory(cellData -> 
                new ReadOnlyStringWrapper(cellData.getValue())
        );
        agencyColumn.setStyle( "-fx-alignment: CENTER;");

        ObservableList<String> agencies = FXCollections.observableArrayList(
                    "AA","DL","LH");
        agencyTableView.getItems().addAll(agencies);
    }    

    @FXML
    private void onAdd(ActionEvent event) {
    }


    @FXML
    private void onOK(ActionEvent event) {
        // Just exit for now
        Stage stage = (Stage) okAgencyButton.getScene().getWindow();
        stage.close();
    }

    @FXML
    private void onCancel(ActionEvent event) {
        // Just exit for now
        Stage stage = (Stage) cancelAgencyButton.getScene().getWindow();
        stage.close();
    }

}

TableButton.java:

package tablebutton;

import java.io.IOException;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

public class TableButton extends Application {

    @Override
    public void start(Stage primaryStage) {
        try
        {
            FXMLLoader loader = new FXMLLoader(getClass().getResource("TableButtonView.fxml"));
            Scene scene = new Scene((Parent) loader.load());
            primaryStage.setScene(scene);
            primaryStage.setTitle("TableView Button Test");
            primaryStage.show();
        }
        catch (IOException ignored)
        {
        }
    }

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

Answer 1

尝试将按钮实际放在 TableView 中是有问题的，不推荐这样做。让按钮呈现在 TableView 的最后一行存在技术困难(这不是微不足道的)，并且还存在潜在的可用性问题(如果表格中有很多行并且表格需要滚动，删除按钮是否只是滚动到 View 之外？如果是这样，那么如果用户想要删除某些内容，他们将如何找到它)。

相反，不要将按钮放在 TableView 中:

1. 使用包含 TableView 和 Button 的 VBox。
2. 设置适当的约束，使 Button 紧贴在 TableView 的下方，并调整到 TableView 的宽度。
3. 将 Button 的禁用属性绑定(bind)到一个空的选定项集。

示例代码:

import javafx.application.Application;
import javafx.beans.binding.Bindings;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

public class Remover extends Application {
    @Override
    public void start(Stage stage) throws Exception {
        ObservableList<NamedColor> colors = FXCollections.observableArrayList(
                new NamedColor("red", Color.RED),
                new NamedColor("green", Color.GREEN),
                new NamedColor("blue", Color.BLUE),
                new NamedColor("indigo", Color.INDIGO)
        );

        TableView<NamedColor> table = new TableView<>(colors);
        table.getSelectionModel().setSelectionMode(SelectionMode.MULTIPLE);
        table.setColumnResizePolicy(TableView.CONSTRAINED_RESIZE_POLICY);
        TableColumn<NamedColor, String> colorNames = new TableColumn<>("Colors");
        colorNames.setCellValueFactory(new PropertyValueFactory<>("name"));
        table.getColumns().add(colorNames);

        Button remove = new Button("Remove");
        remove.disableProperty().bind(
                Bindings.isEmpty(
                        table.getSelectionModel().getSelectedItems()
                )
        );
        remove.setMaxWidth(Double.MAX_VALUE);
        remove.setOnAction(event ->
                table.getItems()
                        .removeAll(
                                table.getSelectionModel().getSelectedItems()
                        )
        );

        VBox layout = new VBox(table, remove);
        layout.setPadding(new Insets(10));

        stage.setScene(new Scene(layout));
        stage.show();
    }

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

    public static class NamedColor {
        private String name;
        private Color color;

        public NamedColor(String name, Color color) {
            this.name = name;
            this.color = color;
        }

        public String getName() {
            return name;
        }

        public Color getColor() {
            return color;
        }
    }
}