Java Paint 组件转换成位图

Question

我需要在位图中绘制组件及其所有子组件的内容。如果我想绘制整个组件，下面的代码可以完美地工作:

public void printComponent(Component c, String format, String filename) throws IOException {
// Create a renderable image with the same width and height as the component
BufferedImage image = new BufferedImage(c.getWidth(), c.getHeight(), BufferedImage.TYPE_INT_ARGB);

    // Render the component and all its sub components
    c.paintAll(image.getGraphics());

    // Render the component and ignoring its sub components
    c.paint(image.getGraphics());
// Save the image out to file
ImageIO.write(image, format, new File(filename));

但我没有找到只绘制该组件的一个区域的方法。有什么想法吗？

Answer 1

你需要这样翻译:

BufferedImage image = new BufferedImage(100, 100, BufferedImage.TYPE_INT_ARGB);

Graphics g = image.getGraphics();
g.translate(-100, -100);

c.paintComponent(g);

g.dispose();

---

带输出的完整示例:

public static void main(String args[]) throws Exception {

    JFrame frame = new JFrame("Test");
    frame.add(new JTable(new DefaultTableModel() {
        @Override
        public int getColumnCount() {
            return 10;
        }
        @Override
        public int getRowCount() {
            return 10;
        }
        @Override
        public Object getValueAt(int row, int column) {
            return row + " " + column;
        }
    }));

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(400, 300);
    frame.setVisible(true);

    BufferedImage image = new BufferedImage(100, 100, BufferedImage.TYPE_INT_ARGB);
    Graphics g = image.getGraphics();
    g.translate(-100, -100);

    frame.paintComponents(g);

    g.dispose();

    ImageIO.write(image, "png", new File("frame.png"));
}