Question

我试图在我使用imageIO调用的图像上绘制自定义多边形。添加多边形后，应输出图像。

以下是我的代码：

public static void setPoints(List<Integer> pointArrayX, List<Integer> pointArrayY,File dest) throws IOException{

BufferedImage image = ImageIO.read(new File(dest+""));
Graphics2D g2d = image.createGraphics();


            g2d.fillRect(0, 0, image.getWidth(), image.getHeight());
            g2d.setColor(Color.RED);
            BasicStroke bs = new BasicStroke(2);
            g2d.setStroke(bs);

                    int[] xPoly = new int[pointArrayX.size()];
                    int[] yPoly = new int[pointArrayY.size()];

            Polygon poly = new Polygon(xPoly,yPoly,xPoly.length);
            poly.getBounds();
            g2d.setPaint(Color.RED);
            g2d.drawPolygon(poly);
            g2d.fillPolygon(xPoly, yPoly, xPoly.length);
            g2d.drawPolygon(xPoly, yPoly, xPoly.length);
            g2d.setStroke(bs);
            g2d.drawPolyline(xPoly, yPoly, xPoly.length);
            g2d.drawOval(100, 100, 200, 200);

            g2d.draw(poly);


            File outputfile = new File(dest+"");
            ImageIO.write(image, "png", outputfile);

一旦运行，输出图像中出现的唯一形状就是我定义的椭圆形。它只是没有出现的Polygon。

Answer 1

您不会填充阵列。

int[] xPoly = new int[pointArrayX.size()]; //create an array and set its size
int[] yPoly = new int[pointArrayY.size()]; //create an array and set its size
Polygon poly = new Polygon(xPoly,yPoly,xPoly.length); //use the created array

您需要将数据添加到xPoly和yPoly。尝试：

int[] xPoly = new int[pointArrayX.size()]; //create an array and set its size
int[] yPoly = new int[pointArrayY.size()]; //create an array and set its size

//loop i added to copy the elements from your method arguments to the new arrays
for(int i = 0; i < xPoly.size(); i++) {
    xPoly[i] = pointArrayX.get(i);
    yPoly[i] = pointArrayY.get(i);
}

Polygon poly = new Polygon(xPoly,yPoly,xPoly.length); //use the created array

Java - 不在输出图像上绘制多边形

1 个答案: