这是 question 的延续.

我正在尝试用 AnchorPane 覆盖图表，我称之为缓冲区。

这是一个代码示例。

package launcher;

import javafx.application.Application;
import javafx.geometry.Bounds;
import javafx.geometry.Side;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.chart.LineChart;
import javafx.scene.chart.NumberAxis;
import javafx.scene.layout.AnchorPane;
import javafx.stage.Stage;

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception {

        NumberAxis numberAxis = new NumberAxis();
        LineChart<Number, Number> chart = new LineChart<>(numberAxis, new NumberAxis());
        chart.getYAxis().setSide(Side.RIGHT);

        AnchorPane buffer = new AnchorPane();
        buffer.setStyle("-fx-background-color: gray;" +
                "-fx-opacity: 0.5");

        AnchorPane anchorPane = new AnchorPane();
        AnchorPane.setTopAnchor(chart, 0.0);
        AnchorPane.setRightAnchor(chart, 0.0);
        AnchorPane.setBottomAnchor(chart, 0.0);
        AnchorPane.setLeftAnchor(chart, 0.0);

        anchorPane.getChildren().addAll(chart, buffer);

        Scene scene = new Scene(anchorPane);
        primaryStage.setScene(scene);
        primaryStage.setMaximized(true);

        primaryStage.show();

        resetBuffer(chart, buffer, anchorPane);

        anchorPane.widthProperty().addListener((observable, oldValue, newValue) -> {

            resetBuffer(chart, buffer, anchorPane);
        });
    }

    private void resetBuffer(LineChart<Number, Number> chart, AnchorPane buffer,
                             AnchorPane anchorPane) {
        Node chartPlot = chart.lookup(".chart-plot-background");

        Bounds bounds = anchorPane.sceneToLocal(
                chartPlot.localToScene(chartPlot.getBoundsInLocal()));

        buffer.setPrefWidth(bounds.getWidth());
        buffer.setPrefHeight(bounds.getHeight());

        AnchorPane.setLeftAnchor(buffer, bounds.getMinX());
        AnchorPane.setTopAnchor(buffer, bounds.getMinY());
    }
}

在我调整舞台大小之前一切正常。当我调整 AnchorPane(缓冲区)大小时，它没有正确覆盖图表。即它不适合尺寸。

如何修复或以正确的方式进行？

最佳答案

希望这能解决问题:

第一种解决方案:

    double sideSizeWidth = (anchorPane.getWidth()-bounds.getWidth());
    double sideSizeHeight= (anchorPane.getHeight()-bounds.getHeight());

    buffer.prefWidthProperty().bind(Bindings.add(
            chart.widthProperty(),
            -sideSizeWidth
    ));
    buffer.prefHeightProperty().bind(Bindings.add(
            chart.heightProperty(),
            -sideSizeHeight
    ));

(需要在resetBuffer中，并且只需要在primaryStage.show()之后的类(class)开始时调用一次)

第二种方案:

 scene.widthProperty().addListener(new ChangeListener<Number>() {
            @Override
            public void changed(ObservableValue<? extends Number> observable, Number oldValue, Number newValue) {
                double dif =oldValue.doubleValue()-newValue.doubleValue();
                buffer.setPrefWidth(buffer.getWidth()-(dif));
            }
        });
        scene.heightProperty().addListener(new ChangeListener<Number>() {
            @Override
            public void changed(ObservableValue<? extends Number> observable, Number oldValue, Number newValue) {
                double dif =oldValue.doubleValue()-newValue.doubleValue();
                buffer.setPrefHeight(buffer.getHeight()-(dif));
            }
        });

它基于轴标签和图例中宽度和高度是永久性的这一事实，因此我们只需要计算场景大小的差异并应用于缓冲区.

全部代码:

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception {
        NumberAxis numberAxis = new NumberAxis();
        LineChart<Number, Number> chart = new LineChart<>(numberAxis, new NumberAxis());
        chart.getYAxis().setSide(Side.RIGHT);

        AnchorPane buffer = new AnchorPane();
        buffer.setStyle("-fx-background-color: gray;" +
                "-fx-opacity: 0.5");

        AnchorPane anchorPane = new AnchorPane();
        AnchorPane.setTopAnchor(chart, 0.0);
        AnchorPane.setRightAnchor(chart, 0.0);
        AnchorPane.setBottomAnchor(chart, 0.0);
        AnchorPane.setLeftAnchor(chart, 0.0);

        anchorPane.getChildren().addAll(chart, buffer);

        Scene scene = new Scene(anchorPane);
        primaryStage.setScene(scene);
        primaryStage.setMaximized(true);

        primaryStage.show();

        resetBuffer(chart, buffer, anchorPane,scene);



    }

    private void resetBuffer(LineChart<Number, Number> chart, AnchorPane buffer,
                             AnchorPane anchorPane,Scene scene) {
        Node chartPlot = chart.lookup(".chart-plot-background");

        Bounds bounds = anchorPane.sceneToLocal(
                chartPlot.localToScene(chartPlot.getBoundsInLocal()));

        buffer.setPrefWidth(bounds.getWidth());
        buffer.setPrefHeight(bounds.getHeight());

        AnchorPane.setLeftAnchor(buffer, bounds.getMinX());
        AnchorPane.setTopAnchor(buffer, bounds.getMinY());

        scene.widthProperty().addListener(new ChangeListener<Number>() {
            @Override
            public void changed(ObservableValue<? extends Number> observable, Number oldValue, Number newValue) {
                double dif =oldValue.doubleValue()-newValue.doubleValue();
                buffer.setPrefWidth(buffer.getWidth()-(dif));
            }
        });
        scene.heightProperty().addListener(new ChangeListener<Number>() {
            @Override
            public void changed(ObservableValue<? extends Number> observable, Number oldValue, Number newValue) {
                double dif =oldValue.doubleValue()-newValue.doubleValue();
                buffer.setPrefHeight(buffer.getHeight()-(dif));
            }
        });

    }
}

关于java - 如何在 JavaFX 8 中使用 AnchorPane 覆盖图表？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/52897993/