在 javafx table 中设置项目，我做错了什么？

Question

我必须初始化 javafx table 但我不知道出了什么问题。我使用了这个：https://docs.oracle.com/javafx/2/ui_controls/table-view.htm 教程，我也在使用 SceneBuilder 和 FXML 来制作 GUI。

主要class：这将设置 window 并创建 table，以及所有列等。它还确保打开或创建将被读取和写入的文件。

public class Main extends Application {

    private AnchorPane rootLayout;

    public void initialize ()
    {
        System.out.println("Initialized");
        try {

            File masterFile = new File(("G:\"),"masterfile.txt"); //I just needed to create the file to be able to access it at a later date


             if (!masterFile.exists()){

                 masterFile.createNewFile();

             }

             MainScreenController table = new MainScreenController();

            table.initializeTable();

             System.setProperty("glass.accessible.force", "false");

        } catch (Exception e) {

            System.out.println("INITIALIZE METHOD WENT HAYWIRE");

        }
    }
    @Override
    public void start(Stage primaryStage) {
        try {
            FXMLLoader root = new FXMLLoader();

            root.setLocation(Main.class.getResource("view/MainScreen.fxml"));
            rootLayout = (AnchorPane) root.load();
            Scene scene = new Scene(rootLayout);
            primaryStage.setResizable(false);
            primaryStage.setScene(scene);
            primaryStage.show();
            initialize();
        } catch(Exception e) {
            e.printStackTrace();
        }
    }




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


}

table 的控制器 class：这是我尝试用我拥有的数据填充列。

@FXML
public Button showAddNewPerson;
@FXML
public Button EditStudentFiles;
@FXML
public Button generateDebtorReport;
@FXML
public Button generateSeniorReport;
@FXML
public TableView<StudentData> dataTable = new TableView<StudentData>();
@FXML
private TableColumn<StudentData, String> firstNameCol = new TableColumn<StudentData, String>();
@FXML
private TableColumn<StudentData, String> lastNameCol = new TableColumn<StudentData, String>();
@FXML
private TableColumn<StudentData, String> schoolCol = new TableColumn<StudentData, String>();
@FXML
private TableColumn<StudentData, String> stateCol = new TableColumn<StudentData, String>();
@FXML
private TableColumn<StudentData, String> emailCol = new TableColumn<StudentData, String>();
@FXML
private TableColumn<StudentData, Integer> yearJoinedCol = new TableColumn<StudentData, Integer>();
@FXML
private TableColumn<StudentData, String> activeCol = new TableColumn<StudentData, String>();
@FXML
private TableColumn<StudentData, Double> debtCol = new TableColumn<StudentData, Double>();

public AnchorPane addNewPersonLayout;

@SuppressWarnings("unchecked")
public void initializeTable() {


    ObservableList<StudentData> observableData = FXCollections.observableArrayList(StudentData.retrieveDataFromFile());//retrieves the array list from the file

    //I think these statements pick out each instance variable of each object in the arrayList
    firstNameCol.setCellValueFactory(new PropertyValueFactory<StudentData, String>("firstName"));
    lastNameCol.setCellValueFactory(new PropertyValueFactory<StudentData, String>("lastName"));
    schoolCol.setCellValueFactory(new PropertyValueFactory<StudentData, String>("schoolName"));
    stateCol.setCellValueFactory(new PropertyValueFactory<StudentData, String>("stateAbbreviaion"));
    emailCol.setCellValueFactory(new PropertyValueFactory<StudentData, String>("studentEmail"));
    yearJoinedCol.setCellValueFactory(new PropertyValueFactory<StudentData, Integer>("yearJoined"));
    activeCol.setCellValueFactory(new PropertyValueFactory<StudentData, String>("areTheyActive"));
    debtCol.setCellValueFactory(new PropertyValueFactory<StudentData, Double>("amountOwed"));

    //sets observable list into the table
    dataTable.setItems(observableData);
    //this is what the tutorial says works
    dataTable.getColumns().addAll(firstNameCol, lastNameCol, schoolCol, stateCol, emailCol, yearJoinedCol, activeCol, debtCol);
}

我真的不明白这个 table 应该如何工作，因为教程让我有点困惑。

Answer 1

首先，确保您已经在 FXML 中定义了控制器 class。

<YourRootElement fx:controller="MyControllerClass">

然后，我不确定您为什么要创建 "visual elements" 的新实例以及为什么将它们定义为 public，但是如果您使用的是 JavaFX 8，则需要定义他们是这样的：

@FXML
private TableView<StudentData> dataTable;

关于你的 Table，你有 3 个选择：

(最好的)初始化controller里面的Table。在调用 main 上的 "show" 方法之前，您应该在控制器上创建初始化方法以填充所有数据。该方法将由 JRE 默认调用...请确保为您的学生提供 Getters Class。
```
public ControllerClass{

    //All your variables and Stuff

   @FXML
   private void initialize(){
   //here is where you initialize your data 
   }
}
```
有一个小技巧可以强制 table 更新，但由于我不能 100% 确定您是否正确收集了数据，所以我不能保证它能正常工作. 在将项目添加到 ObservableList
之后放置此代码
```
dataTable.getColumns().get(0).setVisible(false); 
dataTable.getColumns().get(0).setVisible(true);
```

在 javafx table 中设置项目，我做错了什么？

Setting the items in a javafx table, what am I doing wrong?

java

javafx

tableview