Javafx 如何在画布上画三角形

只有三角形和椭圆形没有三角形的方法

canvas.getGraphicsContext2D()

看一看:

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;

public class BasicOpsTest extends Application {

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

    @Override
    public void start(Stage primaryStage) {
        primaryStage.setTitle("Drawing Operations Test");
        Group root = new Group();
        Canvas canvas = new Canvas(300, 250);
        GraphicsContext gc = canvas.getGraphicsContext2D();
        drawShapes(gc);
        root.getChildren().add(canvas);
        primaryStage.setScene(new Scene(root));
        primaryStage.show();
    }

    private void drawShapes(GraphicsContext gc) {

        int firstX = 90;
        int secondX = 190;
        int thirdX = 10;

        int firstY =30;
        int secondY =170;
        int thirdY =170;

                gc.setFill(Color.GREEN);
        gc.setStroke(Color.BLUE);
        gc.fillPolygon(new double[]{firstX, secondX,thirdX},
                new double[]{firstY, secondY, thirdY}, 3);

        gc.strokePolygon(new double[]{firstX, secondX,thirdX},
                new double[]{firstY, secondY, thirdY}, 3);

        gc.setFill(javafx.scene.paint.Color.BLACK);
        gc.fillText("1", firstX - 3, firstY - 4);
        gc.fillText("2", secondX - 3, secondY - 4);
        gc.fillText("3", thirdX - 3, thirdY - 4);


    }
}