JavaFX嵌入式表FXML提供空指针异常

Question

我正在尝试通过参考YT的一些教程来创建表视图。当我执行一个简单的表格视图及其相关控制器时，它就可以工作。

主类：

    public class TableTest extends Application {

    public TableTest() {
        // TODO Auto-generated constructor stub
    }

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

    @Override
    public void start(Stage stage) throws Exception {
        try {
            // load the fxml file
            FXMLLoader tableloader = new FXMLLoader(getClass().getResource("TestTableView.fxml"));
            Parent root = tableloader.load();

            TableTestController controller = tableloader.getController();
            controller.initializeModel();

            //load the login scene
            Scene scene = new Scene(root, 800, 400);
            stage.setTitle("Test Table Screen");
            stage.setScene(scene);
            stage.show();

        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}

Controller Class：

public class TableTestController {

    @FXML private  TableView<TablePost> t_posts ;
    @FXML private  TableColumn<TablePost, String> c_post_id ;
    @FXML private  TableColumn<TablePost, String> c_post_title ;
    @FXML private  TableColumn<TablePost, String> c_post_desc ;
    @FXML private  TableColumn<TablePost, String> c_post_creator ;

    @FXML private TabPane TabPane;
    @FXML private Tab AllPosts;
    @FXML private AnchorPane t_anch;
    @FXML private TableTestController t_anchController;

    @FXML private Parent TAllPosts;

    public void initializeModel() {
        System.out.println("Starting Table Init");
        c_post_id.setCellValueFactory(new PropertyValueFactory<TablePost, String>("postId"));
        c_post_title.setCellValueFactory(new PropertyValueFactory<TablePost, String>("postTitle"));
        c_post_desc.setCellValueFactory(new PropertyValueFactory<TablePost, String>("postDesc"));
        c_post_creator.setCellValueFactory(new PropertyValueFactory<TablePost, String>("postCreator"));
        t_posts.setItems(getPosts());
        System.out.println("Finished Table Init");
   }

    public ObservableList<TablePost> getPosts() {
        ObservableList<TablePost> posts = FXCollections.observableArrayList();
        TablePost p1 ;
        p1 = new TablePost("id1","title1","desc1","creator1");
        posts.add(p1);
        p1 = new TablePost("id2","title2","desc2","creator2");
        posts.add(p1);
        return posts;
    }

}

TestTableView.fxml：

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

<?import javafx.scene.control.TableColumn?>
<?import javafx.scene.control.TableView?>
<?import javafx.scene.control.cell.PropertyValueFactory?>
<?import javafx.scene.layout.AnchorPane?>

<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity"
    minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0"
    prefWidth="600.0" xmlns="http://javafx.com/javafx/11.0.1"
    xmlns:fx="http://javafx.com/fxml/1"
    fx:id ="t_anch"
    fx:controller="test.TableTestController">

    <children>
        <TableView fx:id="t_posts" layoutX="14.0" layoutY="65.0"
            prefHeight="141.0" prefWidth="570.0">
            <columns>
                <TableColumn fx:id="c_post_id" prefWidth="78.0"
                    text="Post Id" />
                <TableColumn fx:id="c_post_title" prefWidth="135.0"
                    text="Post Title" />
                <TableColumn fx:id="c_post_desc" prefWidth="237.0"
                    text="Post Desc" />
                <TableColumn fx:id="c_post_creator" prefWidth="119.0"
                    text="Post Creator" />
            </columns>
        </TableView>
    </children>
</AnchorPane>

所有这些都有效，但是现在，我将此fxml注入到获得NPE的选项卡视图中。即，如果我将Main类中的第28行更改为引用新的基于Tab的fxml，则会失败

此作品：FXMLLoader tableloader = new FXMLLoader(getClass().getResource("TestTableView.fxml"));

这不起作用：FXMLLoader tableloader = new FXMLLoader(getClass().getResource("TestTableView2.fxml"));

TestTableView2.fxml：

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

<?import javafx.scene.control.Tab?>
<?import javafx.scene.control.TabPane?>
<?import javafx.scene.layout.BorderPane?>

<BorderPane maxHeight="-Infinity" maxWidth="-Infinity"
    minHeight="-Infinity" minWidth="-Infinity" prefHeight="515.0"
    prefWidth="714.0" xmlns="http://javafx.com/javafx/11.0.1"
    xmlns:fx="http://javafx.com/fxml/1"
    fx:controller="test.TableTestController">
    <center>
        <TabPane fx:id="TabPane">
            <tabs>
                <Tab fx:id="AllPosts" closable="false" text="All Posts">
                    <content>
                        <fx:include fx:id="TAllPosts"
                            source="TestTableView.fxml" />
                    </content>
                </Tab>
            </tabs>
        </TabPane>
    </center>
</BorderPane>

Answer 1

您可以简单地在控制器中为TableView2进行初始化。还要在控制器中添加AllPosts而不是fxml：

public class TableView2Controller {

    @FXML private Tab AllPosts;

    @FXML
    public void initialize() throws IOException {

      FXMLLoader loader = new FXMLLoader(getClass().getResource("TestTableView.fxml"));
      Pane pane = loader.load();
      TableTestController controller = loader.getController();
      controller.initializeModel();
      AllPosts.setContent(pane);
   }
}