JavaFx 透明舞台和仍然绘画

Question

我正在尝试制作一个透明的窗口，但我仍然可以在上面绘图并且图纸不透明。如果我把不透明放在舞台上，它会让一切变得透明。我也尝试过为组添加透明度，但这似乎并没有改变任何东西。我怎样才能做到这一点？

        GraphicsDevice gd = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice();
        DisplayMode displayMode = gd.getDisplayMode();

        Canvas canvas = new Canvas(displayMode.getWidth(), displayMode.getHeight());
        GraphicsContext gc = canvas.getGraphicsContext2D();

        Group group = new Group();
        group.getChildren().add(canvas);

        Scene secondScene = new Scene(group, displayMode.getWidth(), displayMode.getHeight());
        gc.setFill(Color.rgb(0, 0, 0, .5));
        gc.fillRect(0, 0, 100, 100);

        // New window (Stage)
        Stage newWindow = new Stage(StageStyle.UNDECORATED);
        newWindow.setOpacity(.02);
        newWindow.setTitle("Second Stage");
        newWindow.setScene(secondScene);

        // Set position of second window, related to primary window.
        newWindow.setX(0);
        newWindow.setY(0);
        //newWindow.setWidth(displayMode.getWidth());
        //newWindow.setHeight(displayMode.getHeight());

        newWindow.show();

Answer 1

所以，基于how to make transparent scene and stage in javafx?，我更新了你的代码，添加了

secondScene.setFill(Color.TRANSPARENT);

和

newWindow.initStyle(StageStyle.TRANSPARENT);

并且能够生产...

import java.awt.DisplayMode;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
import javafx.scene.paint.Color;
import javafx.stage.Stage;
import javafx.stage.StageStyle;

public class Test extends Application {

    @Override
    public void start(Stage primaryStage) {
        GraphicsDevice gd = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice();
        DisplayMode displayMode = gd.getDisplayMode();

        Canvas canvas = new Canvas(displayMode.getWidth(), displayMode.getHeight());
        GraphicsContext gc = canvas.getGraphicsContext2D();

        Group group = new Group();
        group.getChildren().add(canvas);

        Scene secondScene = new Scene(group, displayMode.getWidth(), displayMode.getHeight());
        secondScene.setFill(Color.TRANSPARENT);         gc.setFill(Color.rgb(0, 0, 0, .5));
        gc.fillRect(0, 0, 100, 100);

        // New window (Stage)
        Stage newWindow = new Stage(StageStyle.UNDECORATED);
        newWindow.initStyle(StageStyle.TRANSPARENT);

        newWindow.setTitle("Second Stage");
        newWindow.setScene(secondScene);

        // Set position of second window, related to primary window.
        newWindow.setX(0);
        newWindow.setY(0);
//      newWindow.setWidth(200);
//      newWindow.setHeight(200);

        newWindow.show();
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        launch(args);
    }

}

记住，在处理这类事情时，你需要确保层次结构中的每一层也是透明的