在 JavaFX 中使用多个选择框来过滤列表视图

我正在尝试使用多个选择框为我的列表视图创建一个过滤器函数，但我不知道如何做到这一点，因为我对 JavaFX 还很陌生。

我做了一些研究，听说需要使用过滤列表，但大多数在线示例仅围绕使用文本字段。

这是我的控制器类

@FXML
private ChoiceBox<String> genre;
@FXML
private ChoiceBox<String> branch;
@FXML
private ChoiceBox<String> status;
@FXML
private ChoiceBox<String> company;
@FXML
private ListView<Movie> listView;

private ObservableList<Movie> movieList = FXCollections.observableArrayList();
private FilteredList<Movie> filteredData = new FilteredList<>(movieList, s -> true);

public Controller()  {
        vehicleList.addAll(
                new Movie("Horror" ,"IT", ,"Branch1", "Released", "Warner Bros"),
                new Movie("Action","John Wick 3" ,"Branch2", "Coming Soon", "Summit Entertainment")
        );

@Override
public void initialize(URL location, ResourceBundle resources) {
//I am planning to implement the filter here in the initialize method
        listView.setItems(filteredData);
        listView.setCellFactory(movieListView -> new MovieListViewCell());
}

这是 MovieListViewCell 类

 @FXML
    private Label genre;

    @FXML
    private Label status;

    @FXML
    private GridPane gridPane;

    private FXMLLoader mLLoader;

    @Override
    protected void updateItem(Movie movie, boolean empty) {
        super.updateItem(vehicle, empty);

        if(empty || vehicle == null) {

            setText(null);
            setGraphic(null);

        } else {
            if (mLLoader == null) {
                mLLoader = new FXMLLoader(getClass().getResource("/application/ListCell.fxml"));
                mLLoader.setController(this);

                try {
                    mLLoader.load();
                } catch (IOException e) {
                    e.printStackTrace();
                }

            }

            genre.setText(String.valueOf(vehicle.getMovie_Genre()));
            status.setText(String.valueOf(vehicle.getMovie_Status()));
            setText(null);
            setGraphic(gridPane);
        }

    }

这是我运行整个 UI 的主要方法

public class Main extends Application {
    @Override
    public void start(Stage primaryStage) {
        try {
            Parent root = FXMLLoader.load(getClass().getResource("/application/MainPage.fxml"));
            Scene scene = new Scene(root,800,650);
            primaryStage.setScene(scene);
            primaryStage.show();
        } catch(Exception e) {
            e.printStackTrace();
        }
    }

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

这是我的 FXML 主布局 MainPage.fxml

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

<?import java.lang.String?>
<?import javafx.collections.FXCollections?>
<?import javafx.geometry.Insets?>
<?import javafx.scene.control.ChoiceBox?>
<?import javafx.scene.control.ListView?>
<?import javafx.scene.control.Menu?>
<?import javafx.scene.control.MenuBar?>
<?import javafx.scene.control.MenuItem?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.layout.BorderPane?>
<?import javafx.scene.layout.VBox?>

<BorderPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="application.Controller">
   <center>
      <AnchorPane prefHeight="374.0" prefWidth="262.0" BorderPane.alignment="CENTER">
         <children>
            <ListView fx:id="listView" layoutX="106.0" layoutY="93.0" prefHeight="374.4" prefWidth="400.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
         </children>
      </AnchorPane>
   </center>
   <top>
      <MenuBar BorderPane.alignment="CENTER">
        <menus>
          <Menu mnemonicParsing="false" text="File">
            <items>
              <MenuItem mnemonicParsing="false" text="Close" />
            </items>
          </Menu>
          <Menu mnemonicParsing="false" text="Edit">
            <items>
              <MenuItem mnemonicParsing="false" text="Delete" />
            </items>
          </Menu>
          <Menu mnemonicParsing="false" text="Help">
            <items>
              <MenuItem mnemonicParsing="false" text="About" />
            </items>
          </Menu>
        </menus>
      </MenuBar>
   </top>
   <left>
      <VBox alignment="CENTER" prefHeight="368.0" prefWidth="149.0" BorderPane.alignment="CENTER">
         <children>
            <TextField fx:id="filterField" />
            <ChoiceBox fx:id="type" prefWidth="150.0">
                 <items>
                    <FXCollections fx:factory="observableArrayList">
                        <String fx:value="Horror" />
                        <String fx:value="Action" />
                    </FXCollections>
                 </items>
               <VBox.margin>
                  <Insets bottom="20.0" left="10.0" right="10.0" />
               </VBox.margin>
            </ChoiceBox>
            <ChoiceBox fx:id="branch" prefWidth="150.0">
                <items>
                    <FXCollections fx:factory="observableArrayList">
                        <String fx:value="branch1" />
                        <String fx:value="branch2" />
                        <String fx:value="branch3" />
                    </FXCollections>
                 </items>
               <VBox.margin>
                  <Insets bottom="20.0" left="10.0" right="10.0" />
               </VBox.margin>
            </ChoiceBox>
            <ChoiceBox fx:id="company" prefWidth="150.0">
                <items>
                    <FXCollections fx:factory="observableArrayList">
                        <String fx:value="Warner Bros" />
                        <String fx:value="Summit Entertainment" />
                    </FXCollections>
                 </items>
               <VBox.margin>
                  <Insets bottom="20.0" left="10.0" right="10.0" />
               </VBox.margin>
            </ChoiceBox>
            <ChoiceBox fx:id="status" prefWidth="150.0">
                <items>
                    <FXCollections fx:factory="observableArrayList">
                        <String fx:value="Released" />
                        <String fx:value="Coming Soon" />
                    </FXCollections>
                 </items>
               <VBox.margin>
                  <Insets left="10.0" right="10.0" />
               </VBox.margin>
            </ChoiceBox>
         </children>
      </VBox>
   </left>
</BorderPane>

这是ListCell.fxml

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

<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.image.Image?>
<?import javafx.scene.image.ImageView?>
<?import javafx.scene.layout.ColumnConstraints?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.layout.RowConstraints?>
<?import javafx.scene.layout.VBox?>

<GridPane fx:id="gridPane" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="206.0" prefWidth="534.0" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1">
    <columnConstraints>
      <ColumnConstraints halignment="CENTER" hgrow="SOMETIMES" maxWidth="350.0" minWidth="0.0" prefWidth="284.0" />
        <ColumnConstraints hgrow="SOMETIMES" maxWidth="509.0" minWidth="0.0" prefWidth="56.0" />
        <ColumnConstraints hgrow="SOMETIMES" maxWidth="543.0" minWidth="10.0" prefWidth="55.0" />
      <ColumnConstraints hgrow="SOMETIMES" maxWidth="543.0" minWidth="10.0" prefWidth="119.0" />
    </columnConstraints>
    <rowConstraints>
        <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
    </rowConstraints>
    <children>
      <VBox alignment="CENTER" prefHeight="200.0" prefWidth="100.0">
         <children>
            <ImageView fitHeight="150.0" fitWidth="200.0" pickOnBounds="true" preserveRatio="true">
               <image>
                  <Image url="@../../../../Desktop/Test.jpg" />
               </image>
            </ImageView>
         </children>
      </VBox>
      <VBox alignment="CENTER" prefHeight="212.0" prefWidth="95.0" GridPane.columnIndex="1">
         <children>
            <Label text="Genre:" />
            <Label text="Status:" />
         </children>
      </VBox>
      <VBox alignment="CENTER" prefHeight="183.0" prefWidth="80.0" GridPane.columnIndex="2">
         <children>
            <Label fx:id="genre" text="Label" />
            <Label fx:id="status" text="Label" />
         </children>
      </VBox>
      <VBox alignment="CENTER" prefHeight="225.0" prefWidth="132.0" GridPane.columnIndex="3">
         <children>
            <Button mnemonicParsing="false" text="Button" />
         </children>
      </VBox>
    </children>
</GridPane>

希望有人能为我提供任何解决方案。谢谢

Using a FilteredList如果您想过滤内存中的项目，这是正确的方法。如果你看一下文档 https://openjfx.io/javadoc/12/javafx.base/javafx/collections/transformation/FilteredList.html，你会看到FilteredList has a predicate财产。不出所料，该房产拥有Predicate https://docs.oracle.com/en/java/javase/12/docs/api/java.base/java/util/function/Predicate.html. The Predicate接口是一个功能接口（这意味着它可以是 lambda 表达式或方法引用的目标）其抽象方法接受类型的泛型参数T并返回true or false基于任意逻辑。当您设置predicate的财产FilteredList，它将使用Predicate判断源中是否存在元素ObservableList应该可以通过FilteredList view。随着项目从源中添加和删除ObservableList the FilteredList会自动更新。

不幸的是，如果您更新任何状态Predicate是基于（例如，在ChoiceBoxes) 它不会自动重新应用Predicate关于源的所有元素ObservableList。换句话说，FilteredList不会自动更新，只是因为Predicate的内部状态发生了变化。这意味着每次更新过滤器状态时，您都需要创建一个new Predicate并设置predicate的财产FilteredList。这是创建和使用绑定会有所帮助的地方。 （注意：虽然Callable是的一部分java.util.concurrent包，这里没有并发发生。)

为了创建绑定，我们将使用Bindings.createObjectBinding(Callable,Observable...) https://openjfx.io/javadoc/12/javafx.base/javafx/beans/binding/Bindings.html#createObjectBinding(java.util.concurrent.Callable,javafx.beans.Observable...)。该方法接受一个Callable https://docs.oracle.com/en/java/javase/12/docs/api/java.base/java/util/concurrent/Callable.html（其他功能接口）和一个数组Observable对象。的数组Observables 被称为依赖关系所创造的ObjectBinding并且，当其中任何一个无效时，会导致ObjectBinding根据给定的值重新计算其值Callable。换句话说，Callable每当其中之一被调用Observables 无效。

FilteredList<Movie> filteredList = movieList.filtered(null); // a null Predicate means "always true"

// moved to own variable for clarity (usually inlined with the method call)
Observable[] dependencies = {genre.valueProperty(), branch.valueProperty(), status.valueProperty(), company.valueProperty()};

ObjectBinding<Predicate<Movie>> binding = Bindings.createObjectBinding(() -> {
    Predicate<Movie> predicate = movie -> {
        // test "movie" based on the values of your ChoiceBoxes
    };
    return predicate;
}, dependencies);

filteredList.predicateProperty().bind(binding);

如果您注意到的话，依赖项是value https://openjfx.io/javadoc/12/javafx.controls/javafx/scene/control/ChoiceBox.html#valueProperty你的每一个的属性ChoiceBoxes.属性（即实例ReadOnlyProperty and Property）是以下的实现Observable当它们的值可能改变时，它们就会失效。这意味着每当用户改变他们的选择时，value财产无效，并且Predicate of the FilteredList被改变了。当。。。的时候Predicate更改列表被“重新过滤”。