Question

我试图通过从模态窗口单击按钮来填充方法调用中的TableView。我希望这是可能的，但我没有运气。 TableView已在FXML文件中创建。每当我调用该方法时，我都会收到一个空指针异常。有什么想法或建议吗？对不起，如果我的问题格式不好，我不会问很多问题。

MainController.java

@FXML TableView<Part> partsTableView;
@FXML ObservableList<Part> parts;
@FXML public TableColumn<Part, Integer> partIDColumn;
@FXML public TableColumn<Part, String> partNameColumn;
@FXML public TableColumn<Part, Integer> partILColumn;
@FXML public TableColumn<Part, Double> partPriceColumn;

    @FXML
    public void getPartData(){
      partIDColumn.setCellValueFactory(new PropertyValueFactory<>("id")); (Line 112)
      partNameColumn.setCellValueFactory(new PropertyValueFactory<>("name"));
      partILColumn.setCellValueFactory(new PropertyValueFactory<>("instock"));
      partPriceColumn.setCellValueFactory(new PropertyValueFactory<>("price"));
      partsTableView.setItems(generateData());
    }

    private ObservableList<Part> generateData(){
      parts = FXCollections.observableArrayList();
      parts.add(new Part(0, "Part" , 1 , 25.00));

     return parts;
    }

main.fxml

    <TableView fx:id="partsTableView" layoutX="13.0" layoutY="68.0" prefHeight="344.0" prefWidth="556.0">
      <columns>
        <TableColumn fx:id="partIDColumn" editable="false" prefWidth="138.0" resizable="false" text="Part ID" />
        <TableColumn fx:id="partNameColumn" editable="false" prefWidth="139.0" resizable="false" text="Part Name" />
        <TableColumn fx:id="partILColumn" editable="false" prefWidth="119.0" resizable="false" text="Inventory Level" />
        <TableColumn fx:id="partPriceColumn" editable="false" prefWidth="159.0" resizable="false" text="Price / Cost Per Unit" />
      </columns>
    </TableView>

错误：引起：java.lang.NullPointerException 在ims.MainController.getPartData（MainController.java:112）

我正在使用IntelliJ，我在Scene Builder中构建我的舞台/场景。我很抱歉，如果这很简单，而且我忽略了一些事情，但是，我只是在困难时期搞清楚这一点。

提前感谢您的时间和帮助！

Answer 1

我准备了一个样本。你可以遵循它的逻辑。重点是管理主对话框和模态稀释控制器。您可以在AppMainController.java中查看DialogController dialogController = fxmlLoader.<DialogController>getController();行。在此示例中，主控制器（AppMainController）获取对话框控制器（DialogController）并将其可观察列表设置为对话框控制器。示例类和fxmls如下：

AppMain.java：

package populatetable;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

public class AppMain extends Application{

    @Override
    public void start(Stage primaryStage) throws Exception {

        Parent root = FXMLLoader.load(getClass().getResource("AppMain.fxml"));
        Scene scene = new Scene(root, 500,500);
        primaryStage.setScene(scene);
        primaryStage.show();

    }


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

}

AppMain.fxml

<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.TableColumn?>
<?import javafx.scene.control.TableView?>
<?import javafx.scene.layout.AnchorPane?>

<AnchorPane minHeight="500.0" minWidth="500.0" xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/8.0.111" fx:controller="populatetable.AppMainController">
   <children>
      <TableView fx:id="tvData" layoutX="91.0" layoutY="159.0" prefHeight="300.0" prefWidth="300.0">
        <columns>
          <TableColumn fx:id="colId" prefWidth="75.0" text="ID" />
          <TableColumn fx:id="colName" prefWidth="75.0" text="Name" />
        </columns>
         <columnResizePolicy>
            <TableView fx:constant="CONSTRAINED_RESIZE_POLICY" />
         </columnResizePolicy>
      </TableView>
      <Button layoutX="211.0" layoutY="85.0" mnemonicParsing="false" onAction="#onOpenDialog" text="Open Dialog" />
   </children>
</AnchorPane>

AppMainController.java

package populatetable;
import java.io.IOException;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.stage.Stage;

public class AppMainController implements Initializable {

    @FXML
    private TableView<Data> tvData;

    @FXML
    private TableColumn colId;

    @FXML
    private TableColumn colName;

    private ObservableList<Data> tvObservableList = FXCollections.observableArrayList();

    // Open dialog button click event
    @FXML
    void onOpenDialog(ActionEvent event) throws IOException {
        System.out.println("onOpenDialog clicked");

        FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("Dialog.fxml"));
        Parent parent = fxmlLoader.load();
        DialogController dialogController = fxmlLoader.<DialogController>getController();
        dialogController.setAppMainObservableList(tvObservableList);
        Scene scene = new Scene(parent, 300, 200);
        Stage stage = new Stage();
        stage.setScene(scene);
        stage.show();

    }

    @Override
    public void initialize(URL location, ResourceBundle resources) {
        colId.setCellValueFactory(new PropertyValueFactory<>("id"));
        colName.setCellValueFactory(new PropertyValueFactory<>("name"));
        tvData.setItems(tvObservableList);

    }

    public ObservableList<Data> getTvObservableList() {
        return tvObservableList;
    }


}

DialogController.java

package populatetable;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;

public class DialogController  {


    private ObservableList<Data> appMainObservableList;

    //fill table button click event
    @FXML
    void fillTable(ActionEvent event) {

        Data data = new Data(1, "Name1");
        appMainObservableList.add(data);

    }

    public void setAppMainObservableList(ObservableList<Data> tvObservableList) {
        this.appMainObservableList = tvObservableList;

    }

}

Dialog.fxml

<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.layout.AnchorPane?>

<AnchorPane minHeight="200.0" minWidth="300.0" xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/8.0.111" fx:controller="populatetable.DialogController">
   <children>
      <Button layoutX="115.0" layoutY="89.0" mnemonicParsing="false" onAction="#fillTable" text="Fill Table" />
   </children>
</AnchorPane>

Data.java

package populatetable;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleStringProperty;

public class Data {

    private final SimpleIntegerProperty id;
    private final SimpleStringProperty name;


    public Data(int id, String name) {
        this.id = new SimpleIntegerProperty(id);
        this.name = new SimpleStringProperty(name);
    }

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

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

    public String getName() {
        return name.get();
    }

    public void setName(String nme) {
        name.set(nme);
    }

    @Override
    public String toString() {
        return "id: " + id.get() + " - " + "name: " + name.get();
    }

}

希望它有用。

JavaFX从“模态窗口”窗体在主屏幕上填充TableView

1 个答案: