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如何为TableView创建条件CellValueFactory?

javafx java

Zephyr · 技术社区 · 7 年前

我有一个 TableView 需要显示数据对象中两个值之一的列。

Person nickname 可以填充、空或 null .

个人.java:

import javafx.beans.property.IntegerProperty;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;

public class Person {

    private IntegerProperty id = new SimpleIntegerProperty();
    private StringProperty firstName = new SimpleStringProperty();
    private StringProperty lastName = new SimpleStringProperty();
    private StringProperty nickname = new SimpleStringProperty();

    public Person(int id, String firstName, String lastName, String nickname) {
        this.id.set(id);
        this.firstName.set(firstName);
        this.lastName.set(lastName);
        this.nickname.set(nickname);
    }

    public int getId() {
        return id.get();
    }

    public IntegerProperty idProperty() {
        return id;
    }

    public void setId(int id) {
        this.id.set(id);
    }

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

    public StringProperty firstNameProperty() {
        return firstName;
    }

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

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

    public StringProperty lastNameProperty() {
        return lastName;
    }

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

    public String getNickname() {
        return nickname.get();
    }

    public StringProperty nicknameProperty() {
        return nickname;
    }

    public void setNickname(String nickname) {
        this.nickname.set(nickname);
    }
}

Main.java文件:

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class Main extends Application {

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

    @Override
    public void start(Stage primaryStage) {

        // Simple Interface
        VBox root = new VBox(10);
        root.setAlignment(Pos.CENTER);
        root.setPadding(new Insets(10));

        // Build the simple TableView
        TableView<Person> tableView = new TableView<>();
        TableColumn<Person, String> colId = new TableColumn<>("ID");
        TableColumn<Person, String> colName = new TableColumn<>("Name");

        // Set the cell value factories
        colId.setCellValueFactory(new PropertyValueFactory<>("id"));
        colName.setCellValueFactory(new PropertyValueFactory<>("nickname"));

        // Add the column to the tableview
        tableView.getColumns().addAll(colId, colName);

        // Populate the tableview with a couple of samples
        tableView.getItems().addAll(
                new Person(1, "John", "Williams", null),
                new Person(2, "Marty", "McFly", "Chicken"),
                new Person(3, "Emmett", "Brown", "Doc"),
                new Person(4, "Hans", "Zimmer", "")
        );

        // Add the table to the scene
        root.getChildren().add(tableView);

        // Show the stage
        primaryStage.setScene(new Scene(root));
        primaryStage.setTitle("Sample");
        primaryStage.show();
    }
}

CellValueFactory 这将使用 昵称 属性,但如果为空或null。

如何创建条件 CellValue工厂 我假设它需要为工厂创建一个新的回调函数,但我不确定它是如何工作的。

1 回复 | 直到 7 年前

Slaw 7 年前

hints at ,一种方法是在 cellValueFactory . 这是通过 Bindings.when(ObservableBooleanValue) .

nameCol.setCellValueFactory(features -> {
  var firstName = features.getValue().firstNameProperty();
  var lastName  = features.getValue().lastNameProperty();
  var nickname  = features.getValue().nicknameProperty();

  return Bindings.when(nickname.isEmpty())
      .then(firstName.concat(" ").concat(lastName))
      .otherwise(nickname);
});

这个 isEmpty() null

注:如果 StringExpression 是 无效的 ,则认为为空。