FXML BorderPane在另一个BorderPane中居中

Question

所以，我一直试图将一个边框放在另一个边框（中心部分）中，但到目前为止没有成功。

我尝试过（在从FXML加载的窗格和父场景中）：

• setpadding
• setmargin
• 使用锚窗并设置顶部、底部、左侧和右侧锚
• 在主边框的顶部和左侧添加区域（无效且在调整舞台大小时不起作用）

Pane pane = loader.load();

当前布局：

我正在寻找的结果（大致）

这个想法是，即使当我调整窗口大小时，FXML布局也将留在MainBorderPane的中心；

package sample;


import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Menu;
import javafx.scene.control.MenuBar;
import javafx.scene.control.MenuItem;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;
import javafx.stage.StageStyle;

public class Main extends Application {

    private static BorderPane mainBorderPane;
    private static Scene mainScene;
    private static MenuBar mainMenuBar;
    private static Stage mainStage;

    private static Menu mainMenuFile;
    private static MenuItem mainItemMenuLock;
    private static MenuItem mainItemMenuClose;
    private static Menu mainMenuHelp;
    private static MenuItem mainItemMenuSupport;

    public static BorderPane getMainBorderPane() {
        if (mainBorderPane == null) {
            mainBorderPane = new BorderPane();
        }
        return mainBorderPane;
    }

    public static Scene getMainScene() {
        if (mainScene == null) {
            mainScene = new Scene(getMainBorderPane(), 800, 600);
        }
        return mainScene;
    }

    public static MenuBar getMainMenuBar() {
        if (mainMenuBar == null) {
            mainMenuBar = new MenuBar();

            mainMenuFile = new Menu("File");
            mainItemMenuLock = new MenuItem("Lock Screen");
            mainItemMenuClose = new MenuItem("Close");
            mainMenuFile.getItems().addAll(mainItemMenuLock, mainItemMenuClose);

            mainMenuHelp = new Menu("Help");
            mainItemMenuSupport = new MenuItem("Support");
            mainMenuHelp.getItems().addAll(mainItemMenuSupport);

            mainMenuBar.getMenus().addAll(mainMenuFile, mainMenuHelp);

        }
        return mainMenuBar;
    }

    public static Stage getMainStage() {
        if (mainStage == null) {
            getMainBorderPane().setTop(getMainMenuBar());
            mainStage = new Stage(StageStyle.DECORATED);
        }

        return mainStage;
    }

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

    @Override
    public void init() {
        //
    }

    @Override
    public void start(final Stage initStage) throws Exception{
            UtilMethods.showNewScene("login.fxml");
    }

}

package sample;

import javafx.fxml.FXMLLoader;
import javafx.geometry.Pos;
import javafx.scene.layout.Pane;

public class UtilMethods {

    public static void showNewScene(String fxmlPath) {
        try {

            FXMLLoader loader = new FXMLLoader(UtilMethods.class.getResource(fxmlPath));
            Pane pane = loader.load();
            Main.getMainBorderPane().setCenter(pane);
            Main.getMainBorderPane().setAlignment(pane, Pos.CENTER);

           Main.getMainStage().setScene(Main.getMainScene());
            Main.getMainStage().setAlwaysOnTop(false);
            Main.getMainStage().setResizable(true);
            Main.getMainStage().show();


        }catch (java.io.IOException e){
            System.out.println("Error loading screen" + e.getMessage());
        }
    }
}

LoginController.java

package sample;

import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.control.PasswordField;
import javafx.scene.control.TextField;

public class LoginController {

    @FXML private TextField userIdField;

    @FXML private PasswordField passwordField;

    public void initialize(){
            //
        }

    @FXML
    private void login(ActionEvent event) {
        System.out.println("login");
    }

    @FXML
    private void cancel(){
        userIdField.clear();
        passwordField.clear();
        userIdField.requestFocus();
    }

    @FXML
    private void registerNew(ActionEvent event) throws Exception{
        System.out.println("register new");
    }

}

login.fxml

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

<?import javafx.geometry.Insets?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<GridPane xmlns:fx="http://javafx.com/fxml/1" hgap="10" vgap="10"
          fx:controller="sample.LoginController" GridPane.halignment="CENTER" GridPane.valignment="CENTER">

    <padding>
        <Insets top="10" right="10" bottom="10" left="10"/>
    </padding>
    <children>

        <Label  text="Username:" GridPane.columnIndex="0"
                GridPane.rowIndex="0" GridPane.halignment="RIGHT" />
        <Label  text="Password:" GridPane.columnIndex="0"
                GridPane.rowIndex="1" GridPane.halignment="RIGHT" />
        <Label  text="Database connection status:" GridPane.columnIndex="0"
                GridPane.rowIndex="2" GridPane.halignment="RIGHT" />
        <Label  fx:id="labelDBStatus" text="..." GridPane.columnIndex="1"
                GridPane.rowIndex="2" GridPane.halignment="RIGHT" />

        <TextField fx:id="userIdField" GridPane.columnIndex="1" GridPane.rowIndex="0"
                   promptText="User ID" styleClass="text-field"/>

        <PasswordField fx:id="passwordField" GridPane.columnIndex="1" GridPane.rowIndex="1"
                       promptText="Password" styleClass="text-field"/>

        <HBox GridPane.columnIndex="0" GridPane.rowIndex="3"
              GridPane.columnSpan="2" alignment="CENTER" spacing="10">
            <children>
                <Button fx:id="btnLogin" text="Login" onAction="#login" />
                <Button fx:id="btnCancel" text="Cancel" onAction="#cancel"/>
                <Button fx:id="btnRegister" text="Register" onAction="#registerNew"/>
            </children>
        </HBox>

    </children>

</GridPane>

Answer 1

得到这个结果的原因是，如果某个区域不包含子组件，那么该区域可能会被其他区域占据。在这种情况下，由于GridPane是BorderPane中唯一的组件，它会自动转到左上角。为了避免这种情况，您必须在border窗格中有其他组件，或者考虑使用类似VBox（而不是gridPane）这样的东西，它继承其父维度，以便使屏幕处于中心位置。