加载后如何向javafx窗口添加按钮？

Question

我正在尝试在函数“Initialize()”中添加来自 javaFX 窗口的按钮列表。但我只找到在显示窗口之前学习创建按钮的答案。我想添加到现有的 JavaFx 窗口。 对于这个窗口，我有一个 FXML 文件：

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

<?import javafx.scene.control.Button?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.text.Font?>
<?import javafx.scene.text.Text?>

<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" prefHeight="480.0" prefWidth="640.0" xmlns="http://javafx.com/javafx/17" xmlns:fx="http://javafx.com/fxml/1" fx:controller="FXMLsControllers.sistemalogin.cadernos.cadernoController">
   <children>
      <Text fill="#3f435a" layoutX="51.0" layoutY="88.0" strokeType="OUTSIDE" strokeWidth="0.0" text="Olá,">
         <font>
            <Font size="35.0" />
         </font>
      </Text>
      <Text fill="#3e42599b" layoutX="51.0" layoutY="115.0" strokeType="OUTSIDE" strokeWidth="0.0" text="Seus cadernos">
         <font>
            <Font size="13.0" />
         </font>
      </Text>
      <Button fx:id="voltarBtn" mnemonicParsing="false" onAction="#voltaTela" prefHeight="47.0" prefWidth="63.0" style="-fx-background-color: transparent;" text="&lt;" textFill="#3f435a">
         <font>
            <Font size="23.0" />
         </font>
      </Button>
      <Button layoutX="613.0" layoutY="1.0" mnemonicParsing="false" onAction="#fechaAba" prefHeight="31.0" prefWidth="31.0" style="-fx-background-color: transparent;" text="X" textFill="#3f435a" fx:id="xBtn">
         <font>
            <Font size="16.0" />
         </font>
      </Button>
      <Button fx:id="caderno001" alignment="TOP_LEFT" layoutX="51.0" layoutY="144.0" mnemonicParsing="false" onAction="#entraCaderno" prefHeight="146.0" prefWidth="107.0" style="-fx-background-color: #3f435a;" text="Banco de Dados" textAlignment="CENTER" textFill="WHITE">
         <font>
            <Font size="11.0" />
         </font>
      </Button>
      <Button fx:id="addCadernoBtn" layoutX="538.0" layoutY="373.0" mnemonicParsing="false" onAction="#adicionaCadernoNovo" prefHeight="50.0" prefWidth="53.0" style="-fx-background-color: transparent;" text="+" textFill="#3f435a">
         <font>
            <Font size="24.0" />
         </font>
      </Button>
      <Button fx:id="irDiarioBtn" layoutX="559.0" layoutY="50.0" mnemonicParsing="false" onAction="#abreDiario" prefHeight="12.0" prefWidth="53.0" style="-fx-background-color: #3f435a;" text="Diário" textFill="WHITE">
         <font>
            <Font size="13.0" />
         </font>
      </Button>
      <Text fx:id="nomeLabelText" fill="#3f435a" layoutX="111.0" layoutY="88.0" strokeType="OUTSIDE" strokeWidth="0.0" text="Fulano">
         <font>
            <Font size="35.0" />
         </font>
      </Text>
   </children>
</AnchorPane>

并为此 FXML 创建一个控件。这个控件：

package FXMLsControllers.sistemalogin.cadernos;

import java.io.IOException;
import application.sceneController;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.geometry.Pos;
import javafx.scene.control.Alert;
import javafx.scene.control.Button;
import javafx.scene.control.Alert.AlertType;
import javafx.scene.layout.StackPane;
import javafx.scene.text.Text;
import javafx.stage.Stage;
import javafx.scene.control.ButtonType;
import javafx.scene.control.Button;
import javafx.scene.Parent;



public class cadernoController {

    private String email;
    private String nome;

    public void initData(String email,String nome){
        setEmail(email);
        setNome(nome);
        nomeLabelText.setText(getNome());
        
    }

    @FXML
    public void initialize() throws IOException {
       
       //I want to add a button in this function
    } 

    public String getNome() {
        return nome;
    }

    public void setNome(String nome) {
        this.nome = nome;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    

    @FXML
    private Text nomeLabelText;

    @FXML
    private Button addCadernoBtn;

    @FXML
    private Button caderno001;

    @FXML
    private Button irDiarioBtn;

    @FXML
    private Button voltarBtn;

    @FXML
    private Button xBtn;

    @FXML
    void abreDiario(ActionEvent event) throws IOException {
        mostrarTelaDoDiario(event);
        
    }

    @FXML
    void adicionaCadernoNovo(ActionEvent event) {

    }

    @FXML
    void fechaAba(ActionEvent event) throws IOException {
        Alert alertaFecharApp = new Alert(AlertType.CONFIRMATION);
        alertaFecharApp.setHeaderText("Quer mesmo fechar o aplicativo?");
        alertaFecharApp.setContentText("Bloquim sentirá a sua falta.");
        if(alertaFecharApp.showAndWait().get() != ButtonType.OK){
            return;
        }
        else{
            System.exit(0);
            fecharStage();
            mostrarTelaLogin(event);
        }
    }
    

    @FXML
    void entraCaderno(ActionEvent event) throws IOException {
        mostrarTelaDeAnotação(event);
    }

    @FXML
    void voltaTela(ActionEvent event) throws IOException {
        Alert alert = new Alert(AlertType.CONFIRMATION);
        alert.setHeaderText("Quer mesmo voltar à tela de Login?");
        alert.setContentText("Voltar à tela de Login irá resultar em um processo de Logoff.");
        if(alert.showAndWait().get() != ButtonType.OK){
            return;
        }
        
    }

    private void mostrarTelaDoDiario(ActionEvent event) throws IOException{
        fecharStage();
        sceneController sc = new sceneController();
        sc.trocarParaTelaDiario(event,getEmail(),getNome());
    }
    
    private void mostrarTelaDeAnotação(ActionEvent event) throws IOException{
        fecharStage();
        sceneController sc = new sceneController();
        sc.trocarParaTelaAnotacoes(event,getEmail(),getNome());
    }

    private void mostrarTelaLogin(ActionEvent event) throws IOException{
        fecharStage();
        sceneController sc = new sceneController();
        sc.trocarParaTelaLogin(event);
    }


    private void fecharStage(){
        Stage stage = (Stage) xBtn.getScene().getWindow();
        stage.close();
    }


}
   

我可以访问所有现有元素，但我想添加一个新按钮。在我对 DB 进行咨询之后，需要加载这个按钮，并且在我需要在这个表上创建一个来自哪个注册表的按钮之后。所以，因此，我需要在加载窗口后创建一个按钮。

Answer 1

大概是您希望将按钮添加到的 AnchorPane。

将fx:id 添加到窗格 FXML 元素：

<AnchorPane fx:id="pane" ... >

将pane 的引用注入到您的控制器中：

@FXML
private AnchorPane pane;

在initialize方法中将按钮添加到窗格中；

public void initialize() throws IOException {
    Button button = new Button("New Button");
    AnchorPane.setTopAnchor(button, 10.0);
    AnchorPane.setRightAnchor(button, 10.0);
    pane.getChildren.add(button);
} 

因为它是一个AnchorPane，它不会自动定位孩子，所以您需要手动定位按钮。您应该根据需要调整按钮位置。