JavaFX 13:listview在打开和关闭新窗口后不会更新项目 [英] JavaFX 13 : listview does not update items after opening and closing new window

问题描述

我正在制作一个将事件添加到列表中的程序，但是当我添加事件时，它在关闭addEvent Window之后不会更新列表，这是Senario:

i'm making a program that add events in a list but when i add event it doesn't update my list after closing addEvent Window , here is the senario :

1-这是第一个窗口:

1- this is the first window :

2-然后我按(+)按钮在addEvent窗口中添加事件:

2- then i press the (+) button to add event in addEvent window :

在这里，当我按确定"以测试我的代码时，我会添加测试"项

here i add "test" item when i press ok to test my code

3-现在我按下确定"按钮并返回主窗口:

3- now i press "ok" button and return to the main window :

现在我的列表中没有任何变化，并且没有显示该测试"项目，但是此项目"已经在列表中并成功添加.

now nothing change in my list and it doesn't show that "test" item but this "item" already in the list and added successfully.

这是所有代码:

• 主班

    public static void main(String[] args) {

        launch(args);
    }

    @Override
    public void start(Stage primaryStage) throws Exception{
        FXMLLoader loader = new FXMLLoader(getClass().getResource("main_layout.fxml"));
        Parent root = (Parent) loader.load();   
        primaryStage.setTitle("Goba To Do List");
        Scene scene = new Scene(root);
        primaryStage.setScene(scene);
        primaryStage.setResizable(false);
        primaryStage.show();
    }

• MainController类

    @FXML
    private ListView<String> LeftSideListId; // this names just for testing
    @FXML
    private ListView<String> RightSideListId; // this names just for testing
    @FXML
    private Button AddEvent;

    public void initialize() throws Exception {
        System.out.println("init");

        ObservableList<String>eventsNamesList=FXCollections.observableArrayList(
                "Daily Events","Custom Events","Completed Events");

        LeftSideListId.setItems(eventsNamesList);

        ObservableList<String>eventsList=FXCollections.observableArrayList(
                "item1","item2","item3");

        RightSideListId.setItems(eventsList);

        AddEvent.setOnAction(new EventHandler<ActionEvent>() {

            @Override
            public void handle(ActionEvent arg0) {
                AddButtonPressed();
                }   
        });
    }

    void AddButtonPressed() {

        addEventController.DisplayAddEventWindow();

    }
    public void DisplayAddEventWindow()
     {
         try {
             Stage primaryStage = new Stage();
             primaryStage.setTitle("Add Event");
             Scene scene = new Scene(AddEventScene);
             primaryStage.initModality(Modality.APPLICATION_MODAL);
             primaryStage.setScene(scene);
             primaryStage.setResizable(false);
             primaryStage.show();
         }
         catch(Exception e) 
         {
             e.printStackTrace();
         }
     }

    public void RefreshList() {
        System.out.println("refresh");

        RightSideListId.getItems().add("test");
        System.out.println(RightSideListId.getItems()); // here i get [item1,item2,item3,test]
    }

• AddEventController类

    @FXML
    private Button BtnOk;
    @FXML
    private Button BtnCancel;

    public void initialize() throws Exception {

         BtnOk.setOnAction(new EventHandler<ActionEvent>() {
             @Override
             public void handle(ActionEvent arg0) {
                 try {
                    BtnOkPressed();
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
             }  
         });
         BtnCancel.setOnAction(new EventHandler<ActionEvent>() {
             @Override
             public void handle(ActionEvent arg0) {
                 BtnCancelPressed();
             }  
         });    
     }

     public void BtnCancelPressed() {
         Stage stg= (Stage)BtnCancel.getScene().getWindow();
         stg.close();

    }

    public void BtnOkPressed() throws Exception {
         Stage stg= (Stage)BtnOk.getScene().getWindow();
         stg.close();
         FXMLLoader loader = new FXMLLoader(getClass().getResource("main_layout.fxml"));
         Parent root = (Parent) loader.load();
         MainController mainController=loader.getController();
         mainController.RefreshList();
    }

那我在这里做错了什么?

so what i did wrong here ?

如果我没有打开任何窗口，则列表会正常更新，因此仅在同一窗口中时才会更新... idk为什么

my list updates normally if i didn't open any windows so it is updating only while in the same window... idk why

推荐答案

我创建了一个演示解决方案的示例.此解决方案使用了来自Jewelsea的答案的建议此处.基本上，打开一个新窗口，然后在关闭窗口时使用Optional返回String或不返回任何内容.这是一个快速的答案.我仍然更喜欢Jame_D的MVC想法，而不是这个答案.此解决方案并不意味着是完美的.这只是显示解决问题的方法.

I created an Example that demos a solution. This solution uses ideas from Jewelsea's answer here. Basically, open a new window and when you close the window return a String or nothing using Optional. This is a quick answer. I still prefer Jame_D's MVC ideas over this answer. This solution is not meant to be perfect. It's only to show a way to solve the problem.

主要

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

import java.io.IOException;

/**
 * JavaFX App
 */
public class App extends Application {

    private static Scene scene;

    @Override
    public void start(Stage stage) throws IOException {
        scene = new Scene(loadFXML("primary"), 640, 480);
        stage.setScene(scene);
        stage.show();
    }

    private static Parent loadFXML(String fxml) throws IOException {
        FXMLLoader fxmlLoader = new FXMLLoader(App.class.getResource(fxml + ".fxml"));
        return fxmlLoader.load();
    }

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

}

主控制器

import java.io.IOException;
import java.net.URL;
import java.util.Optional;
import java.util.ResourceBundle;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.ListView;
import javafx.stage.Stage;

public class PrimaryController implements Initializable{
    @FXML ListView<String> lvMain;
    @FXML Button btnAddNewItem;

    ObservableList<String>eventsList = FXCollections.observableArrayList("item1","item2","item3");

    @Override
    public void initialize(URL url, ResourceBundle rb) {    
        lvMain.setItems(eventsList);

        btnAddNewItem.setOnAction((actionEvent) ->
        {
            try
            {
                FXMLLoader addNewItemLoader = new FXMLLoader(getClass().getResource("secondary.fxml"));
                Stage secondStage = new Stage();
                secondStage.setScene(new Scene(addNewItemLoader.load()));
                SecondaryController addNewItemController = addNewItemLoader.getController();                  
                secondStage.showAndWait();
                Optional<String> result = addNewItemController.getNewItem();
                if (result.isPresent()){
                    System.out.println("Your name: " + result.get());
                    eventsList.add(result.get());
                }
            }
            catch (IOException e)
            {
                System.out.println(e.toString());
            }            
        });        
    }
}

主要FXML

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

<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.ListView?>
<?import javafx.scene.layout.VBox?>

<VBox alignment="CENTER" prefHeight="393.0" prefWidth="508.0" spacing="20.0" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sed.test.javafxfxmltestinggrounds.PrimaryController">
   <padding>
      <Insets bottom="20.0" left="20.0" right="20.0" top="20.0" />
   </padding>
   <children>
      <ListView fx:id="lvMain" prefHeight="200.0" prefWidth="200.0" />
      <Button fx:id="btnAddNewItem" mnemonicParsing="false" text="+" />
   </children>
</VBox>

辅助控制器(添加新项目"窗口)

import java.net.URL;
import java.util.Optional;
import java.util.ResourceBundle;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Button;
import javafx.scene.control.TextArea;
import javafx.stage.Stage;

public class SecondaryController implements Initializable{

    @FXML TextArea taSecondary;
    @FXML Button btnOk, btnCancel;

    Optional<String> returnValue;

    @Override
    public void initialize(URL url, ResourceBundle rb) {          
        btnOk.setOnAction((actionEvent) ->
        {
            returnValue = Optional.of(taSecondary.getText());
            ((Stage)(((Button)actionEvent.getSource()).getScene().getWindow())).close();

        });   

        btnCancel.setOnAction((actionEvent) ->
        {
            returnValue = Optional.empty();
            ((Stage)(((Button)actionEvent.getSource()).getScene().getWindow())).close();
        });
    }

    public Optional<String> getNewItem()
    {
        return returnValue;
    }
}

辅助FXML

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

<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.TextArea?>
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.layout.VBox?>

<VBox alignment="CENTER" spacing="20.0" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sed.test.javafxfxmltestinggrounds.SecondaryController">
    <padding>
        <Insets bottom="20.0" left="20.0" right="20.0" top="20.0" />
    </padding>
   <children>
      <TextArea fx:id="taSecondary" prefHeight="200.0" prefWidth="200.0" />
      <HBox alignment="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" spacing="5.0">
         <children>
            <Button fx:id="btnOk" mnemonicParsing="false" prefWidth="52.0" text="OK" />
            <Button fx:id="btnCancel" mnemonicParsing="false" prefWidth="52.0" text="Cancel" />
         </children>
      </HBox>
   </children>
</VBox>

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