如何在显示 JavaFX 警报对话框位置之前对其进行设置

Question

我想在显示警报对话框后在右下角设置警报对话框位置。

这是代码：

package alert;
import javafx.application.Application;
import javafx.geometry.Rectangle2D;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Alert;
import javafx.scene.control.Button;
import javafx.scene.layout.StackPane;
import javafx.stage.Screen;
import javafx.stage.Stage;
public class MainAlert extends Application {
    @Override
    public void start(Stage stage) throws Exception {
        Scene scene = new Scene(createContent());
        stage.setScene(scene);
        stage.setMaximized(true);
        stage.show();
    }
    private Parent createContent() {
        StackPane stackPane = new StackPane();
        Alert alert = new Alert(Alert.AlertType.ERROR);
        alert.setTitle("Error Dialog");
        alert.setHeaderText("Something went wrong");
        alert.setContentText("There is an error!");
        Button alertButton = new Button("Alert test");
        alertButton.setOnAction(event -> {
            Rectangle2D bounds = Screen.getPrimary().getVisualBounds();
            System.out.println("alert.getWidth() = " + alert.getWidth());
            System.out.println("alert.getHeight() = " + alert.getHeight());
            alert.setX(bounds.getMaxX() - alert.getWidth());
            alert.setY(bounds.getMaxY() - alert.getHeight());
            alert.showAndWait();
        });
        stackPane.getChildren().add(alertButton);
        return stackPane;
    }
}

但它的位置在左上角。原因是alert.getWidth()，alert.getHeight()总是返回NaN.我已经试过Platform.runLater()了，不幸的是没有用。

如何解决？

Answer 1

使用硬编码的警报宽度和高度来设置alert.setX()和alert.setY()，并在操作事件中实例化Alert

private Parent createContent() {
        StackPane stackPane = new StackPane();
        Button alertButton = new Button("Alert test");
        alertButton.setOnAction(event -> {
            Alert alert = new Alert(Alert.AlertType.ERROR);
            alert.setTitle("Error Dialog");
            alert.setHeaderText("Something went wrong");
            alert.setContentText("There is an error!");
            Rectangle2D bounds = Screen.getPrimary().getVisualBounds();
            alert.setX(bounds.getMaxX() - 366);
            alert.setY(bounds.getMaxY() - 185);
            alert.showAndWait();
        });
        stackPane.getChildren().add(alertButton);
        return stackPane;
    }

Answer 2

尝试

Alert alert = new Alert(Alert.AlertType.ERROR);
DialogPane pane = alert.getDialogPane();
pane.setPrefHeight(150.0);
alert.setWidth(pane.getWidth());
Rectangle2D bounds = Screen.getPrimary().getBounds();
alert.setX(bounds.getMaxX() - alert.getWidth());
alert.setY(bounds.getMaxY() - pane.getPrefHeight() - 25);

如果您有一个修饰的警报窗口，则需要 - 25。这很丑陋，但目前是我能想到的最好的解决方案。此外，您可能还需要考虑操作系统的任务栏。