从画布中删除 GraphicsContext 形状

如何解决从画布中删除 GraphicsContext 形状

我运行了一个小游戏，我想知道如何删除/删除 GraphicsContext 中的形状。 当其中一个 if 语句适合时，我想删除一个 Rectangle 。可悲的是，我不知道是否有删除它的方法。

希望你能帮帮我

targets.setFill(Color.RED);
            //Problem area
            for (countCol = 1; countCol <= 10; countCoL++) {
                for (countRow = 1; countRow <= 3; countRow++) {
                    targets.fillRect(countRow * gapX + startX,countCol * gapY + startY,brickW,brickH);
                    if (ballXPos + rad >= (countRow * gapX + startX) && ballXPos + rad <= (countRow * gapX + startX) + brickW && ballYPos + rad == (countCol * gapY + startY)) {
                        ballYSpeed *= -1;
                    }
                    if (ballXPos + rad >= (countRow * gapX + startX) && ballXPos + rad <= (countRow * gapX + startX) + brickW && ballYPos + rad == (countCol * gapY + startY) + brickH) {
                        ballYSpeed *= -1;
                    }
                    if (ballXPos + rad == (countRow * gapX + startX) && ballYPos + rad >= (countCol * gapY + startY) && ballYPos + rad <= (countCol * gapY + startY) + brickH) {
                        ballXSpeed *= -1;
                    }
                    if (ballXPos + rad == (countRow * gapX + startX) + brickW && ballYPos + rad >= (countCol * gapY + startY) && ballYPos + rad <= (countCol * gapY + startY) + brickH) {
                        ballXSpeed *= -1;
                    }
                }
            }