我想从模板在javaFX中动态创建节点

Question

我很难弄清楚如何在JavaFX中动态创建节点，我正在尝试为消息传递程序创建一个接口，我希望每个消息都包含在自己的节点中。我不知道将发送多少消息，因此需要根据需要创建新节点。

这就是我到目前为止所做的，我希望这样我可以添加多个MessageNode对象并显示它们

package stackkoverflow.stackoverflow;

import javafx.fxml.FXML;
import javafx.scene.control.Label;

public class MessageControler {
    @FXML
    private Label sender;
    @FXML
    private Label message;

    private MessageNode messagenode;

    public MessageControler(MessageNode messagenode){
        this.messagenode = messagenode;
    }

    @FXML
    private void initialize(){
        sender.textProperty().bind(messagenode.senderProperty());
        message.textProperty().bind(messagenode.messageProperty());
    }

}

package stackkoverflow.stackoverflow;

import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;

public class MessageNode {

    private StringProperty sender = new SimpleStringProperty();
    private StringProperty message = new SimpleStringProperty();

    public MessageNode(String sender, String message){
        this.sender.set(sender);
        this.message.set(message);
    }

    public String getSender(){
        return sender.get();
    }
    public String getMessage(){
        return message.get();
    }
    public void setSender(String sender) {
        this.sender.set(sender);
    }
    public void setMessage(String message) {
        this.message.set(message);
    }
    public StringProperty senderProperty(){
        return sender;
    }
    public StringProperty messageProperty(){
        return message;
    }



}

package stackkoverflow.stackoverflow;

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

import java.io.IOException;

public class test extends Application {


    @Override
    public void start(Stage primaryStage) {
        MessageNode messageNodeTest = new MessageNode("user","hello world");
        MessageNode messageNodeTest1 = new MessageNode("user","hello world");
        MessageNode messageNodeTest2 = new MessageNode("user","hello world");
        MessageNode messageNodeTest3 = new MessageNode("user","hello world");

        try {
            FXMLLoader loader = new FXMLLoader(getClass().getResource("Display.fxml"));
            MessageControler controller = new MessageControler(messageNodeTest);

            loader.setController(controller);

            primaryStage.setScene(new Scene(loader.load()));
            primaryStage.show();

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

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

}

Answer 1

您可以加载FXML并在列表单元格中显示每个实例，将消息节点添加到列表视图中

首先，更改MessageController类，以便可以更改MessageNode（注意：我将重命名该类Message，因为它是数据而不是场景图节点）。这一点很重要，因为您只希望为每个单元格加载一次FXML，而不是为每个项目加载一次：

import javafx.fxml.FXML;
import javafx.scene.control.Label;

public class MessageController {
    @FXML
    private Label sender;
    @FXML
    private Label message;

    private MessageNode messageNode ;

    public void setMessageNode(MessageNode messageNode){
        this.messageNode = messageNode ;
        sender.textProperty().unbind();
        message.textProperty().unbind();
        if (messageNode == null) {
            sender.setText("");
            message.setText("");
        } else {
            sender.textProperty().bind(messageNode.senderProperty());
            message.textProperty().bind(messageNode.messageProperty());
        }
    }

}

现在您可以执行以下操作：

// injected by FXML or just created in code, as needed:
ListView<MessageNode> listView ;

// ...

listView.setCellFactory(lv -> new ListCell<>() {

    private Node graphic ;
    private MessageController controller ;

    {
        try {
            FXMLLoader loader = new FXMLLoader(getClass().getResource("Display.fxml"));
            graphic = loader.load();
            controller = loader.getController();
        } catch (Exception exc) {
            exc.printStackTrace();
        }
    }

    @Override
    protected void updateItem(MessageNode message, boolean empty) {
        super.updateItem(message, empty);
        controller.setMessageNode(message);
        if (empty || message == null) {
            setGraphic(null);
        } else {
            setGraphic(graphic);
        }
    }
});

当然了

listView.getItems().add(new MessageNode(...));

你需要什么时间都行。