Question

我尝试创建一个内部类来创建基于给定变量的三角形，然后在JavaFX场景中显示它。我的当前代码如下所示：

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}

当我调试代码时，它似乎突破了这一行：

public class OuterClass extends Application {
public class InnerClass extends Polygon {
    Polygon triangle;
    InnerClass(double x, double y, double side) {
        double mySideSqrt = Math.sqrt((side * side) - (side / 2 * side / 2)) / 2;
        double tX = x;
        double tY = y - mySideSqrt;
        double rX = x + side / 2;
        double rY = y + mySideSqrt;
        double lX = x - side / 2;
        double lY = y + mySideSqrt;

        Polygon triangle = new Polygon(tX, tY, rX, rY, lX, lY);
        this.triangle = triangle;
    }
}

@Override
public void start(Stage primaryStage) {
    int myWidth = 600;
    int myHeight = 519;

    primaryStage.setTitle("Triangle");
    Group root = new Group();
    Scene scene = new Scene(root, myWidth, myHeight);

    //Polygon triangle = new Polygon(100.0, 0.0, 200.0, 173.3, 0, 173.3); //100.0, 0.0, 200.0, 100.0, 0.0, 100.0
    InnerClass triangle = new InnerClass(300, 260, 196);
    triangle.setFill(Color.LIGHTGRAY);
    root.getChildren().add(triangle);
    primaryStage.setScene(scene);
    primaryStage.show();
}

因为在内部类中创建的三角形不会被拉入方法，因此不会显示在场景中。

关于我如何让它发挥作用的任何想法？

Answer 1

删除Polygon triangle;并将Polygon triangle = new Polygon(tX, tY, rX, rY, lX, lY); this.triangle = triangle;更改为getPoints().addAll(tX, tY, rX, rY, lX, lY);

全班：

public class InnerClass extends Polygon {
    InnerClass(double x, double y, double side) {
        double mySideSqrt = Math.sqrt((side * side) - (side / 2 * side / 2)) / 2;
        double tX = x;
        double tY = y - mySideSqrt;
        double rX = x + side / 2;
        double rY = y + mySideSqrt;
        double lX = x - side / 2;
        double lY = y + mySideSqrt;

        getPoints().addAll(tX, tY, rX, rY, lX, lY);
    }
}

使用内部类在JavaFX中显示三角形

1 个答案: